Built 2026-10-15 (15 October 2026)

Great Falls Weather Records (CA005031200)

Record envelope, standing records and threshold days for Great Falls (CA005031200), Manitoba, Canada, with 82 years of record.

Key Facts for Great Falls

  • Great Falls (CA005031200) is a weather station in Manitoba, Canada at 50.47 latitude and -96.00 longitude, 249 m (817 ft) above sea level.
  • The station reports from 1922 to 2003, 82 years of record.
  • 1,464 records set at Great Falls still stand.
  • Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
  • Great Falls set a daily record low maximum temperature of -24.5 C (-12.1 F) on 22 December 1983.

About the Station

  • Location: Manitoba, Canada, 50.47 latitude, -96.00 longitude.
  • Elevation: 249 m (817 ft).
  • Period of record: 1922 to 2003, 82 years.
  • Eligible elements: tmax, tmin, prcp, snow.

Daily Record Envelope and 2026

0 days at or beyond a record
Daily record high and record low at Great Falls, with 2026 drawn through them The band shows the record high and record low for each calendar day at Great Falls. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -60-40-2002040 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Great Falls. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Great Falls, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan6.1 C (43.0 F)-45.6 C (-50.1 F)n/an/a
Feb11.1 C (52.0 F)-45.6 C (-50.1 F)n/an/a
Mar22.2 C (72.0 F)-38.3 C (-36.9 F)n/an/a
Apr34.0 C (93.2 F)-31.7 C (-25.1 F)n/an/a
May36.0 C (96.8 F)-13.3 C (8.1 F)n/an/a
Jun37.2 C (99.0 F)-3.3 C (26.1 F)n/an/a
Jul40.0 C (104.0 F)3.9 C (39.0 F)n/an/a
Aug38.9 C (102.0 F)-2.2 C (28.0 F)n/an/a
Sep35.5 C (95.9 F)-6.1 C (21.0 F)n/an/a
Oct30.6 C (87.1 F)-16.7 C (1.9 F)n/an/a
Nov22.2 C (72.0 F)-32.8 C (-27.0 F)n/an/a
Dec8.3 C (46.9 F)-43.9 C (-47.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Great Falls by the year they were set 1,464 records at Great Falls still stand. 1936 holds the most, with 60. 02040601922: 91923: 581924: 251925: 181926: 181927: 191928: 261929: 141930: 211931: 271932: 431933: 431934: 351935: 331936: 601937: 151938: 211939: 221940: 181941: 301942: 241943: 161944: 131945: 291946: 211947: 231948: 91949: 281950: 331951: 171952: 281953: 291954: 171955: 171956: 221957: 81958: 311959: 181960: 141961: 171962: 221963: 311964: 291965: 141966: 201967: 241968: 241969: 191970: 201971: 121972: 281973: 111974: 201975: 191976: 191977: 421978: 141979: 251980: 241981: 251982: 181983: 35192219291936194319501957196419711978
1,464 records at Great Falls still stand. 1936 holds the most, with 60.
Standing records at Great Falls by the year they were set
Year setStanding records
19229
192358
192425
192518
192618
192719
192826
192914
193021
193127
193243
193343
193435
193533
193660
193715
193821
193922
194018
194130
194224
194316
194413
194529
194621
194723
19489
194928
195033
195117
195228
195329
195417
195517
195622
19578
195831
195918
196014
196117
196222
196331
196429
196514
196620
196724
196824
196919
197020
197112
197228
197311
197420
197519
197619
197742
197814
197925
198024
198125
198218
198335

All-Time Record Progression

3 new records
When Great Falls set new all-time records 3 all-time records were set at Great Falls between 20 December 1955 and 14 June 1973. Each dot is a new record. Record daily snowfallRecord low maximum temperatureRecord daily precipitation20 December 1955: Record daily snowfall 35.6 cm (14.0 in)14 January 1972: Record low maximum temperature -33.9 C (-29.0 F)14 June 1973: Record daily precipitation 73.9 mm (2.9 in)1955196019651970
3 all-time records were set at Great Falls between 20 December 1955 and 14 June 1973. Each dot is a new record.
When Great Falls set new all-time records
DateKindDetail
1955-12-20Record daily snowfallRecord daily snowfall 35.6 cm (14.0 in)
1972-01-14Record low maximum temperatureRecord low maximum temperature -33.9 C (-29.0 F)
1973-06-14Record daily precipitationRecord daily precipitation 73.9 mm (2.9 in)

Wettest Day of Each Month

Jun: 73.9 mm (2.9 in)
Record daily precipitation for each month at Great Falls The wettest day on record for each calendar month at Great Falls. The most was 73.9 mm (2.9 in) on 14 June 1973. 020406080 Jan: 27.9 mm (1.1 in), 23 January 1943 Jan Feb: 25.4 mm (1.0 in), 12 February 1961 Feb Mar: 27.9 mm (1.1 in), 5 March 1944 Mar Apr: 24.9 mm (1.0 in), 28 April 1954 Apr May: 49.0 mm (1.9 in), 19 May 1974 May Jun: 73.9 mm (2.9 in), 14 June 1973 Jun Jul: 59.4 mm (2.3 in), 2 July 1935 Jul Aug: 55.4 mm (2.2 in), 30 August 1944 Aug Sep: 61.5 mm (2.4 in), 3 September 1941 Sep Oct: 49.8 mm (2.0 in), 10 October 1949 Oct Nov: 22.9 mm (0.9 in), 15 November 1955 Nov Dec: 35.6 mm (1.4 in), 20 December 1955 Dec
The wettest day on record for each calendar month at Great Falls. The most was 73.9 mm (2.9 in) on 14 June 1973.
Record daily precipitation for each month at Great Falls
MonthRecord daily precipitation (mm)Date
Jan27.9 mm (1.1 in)23 January 1943
Feb25.4 mm (1.0 in)12 February 1961
Mar27.9 mm (1.1 in)5 March 1944
Apr24.9 mm (1.0 in)28 April 1954
May49.0 mm (1.9 in)19 May 1974
Jun73.9 mm (2.9 in)14 June 1973
Jul59.4 mm (2.3 in)2 July 1935
Aug55.4 mm (2.2 in)30 August 1944
Sep61.5 mm (2.4 in)3 September 1941
Oct49.8 mm (2.0 in)10 October 1949
Nov22.9 mm (0.9 in)15 November 1955
Dec35.6 mm (1.4 in)20 December 1955

Period of Record Coverage

1922 to 1983
Days with data per year at Great Falls 62 years of record at Great Falls, 1922 to 1983. 3 years have data for under 90 percent of days and are left out of rankings: 1922, 1925, 1926. 1922: 122 of 365 days1923: 364 of 365 days1924: 364 of 366 days1925: 198 of 365 days1926: 307 of 365 days1927: 365 of 365 days1928: 366 of 366 days1929: 365 of 365 days1930: 365 of 365 days1931: 365 of 365 days1932: 335 of 366 days1933: 365 of 365 days1934: 365 of 365 days1935: 365 of 365 days1936: 366 of 366 days1937: 365 of 365 days1938: 365 of 365 days1939: 365 of 365 days1940: 366 of 366 days1941: 365 of 365 days1942: 363 of 365 days1943: 365 of 365 days1944: 366 of 366 days1945: 365 of 365 days1946: 365 of 365 days1947: 364 of 365 days1948: 366 of 366 days1949: 365 of 365 days1950: 365 of 365 days1951: 365 of 365 days1952: 366 of 366 days1953: 365 of 365 days1954: 364 of 365 days1955: 365 of 365 days1956: 336 of 366 days1957: 365 of 365 days1958: 364 of 365 days1959: 365 of 365 days1960: 366 of 366 days1961: 365 of 365 days1962: 365 of 365 days1963: 365 of 365 days1964: 366 of 366 days1965: 365 of 365 days1966: 365 of 365 days1967: 365 of 365 days1968: 366 of 366 days1969: 365 of 365 days1970: 365 of 365 days1971: 365 of 365 days1972: 366 of 366 days1973: 365 of 365 days1974: 365 of 365 days1975: 365 of 365 days1976: 366 of 366 days1977: 360 of 365 days1978: 360 of 365 days1979: 365 of 365 days1980: 364 of 366 days1981: 333 of 365 days1982: 333 of 365 days1983: 363 of 365 days193019401950196019701980
62 years of record at Great Falls, 1922 to 1983. 3 years have data for under 90 percent of days and are left out of rankings: 1922, 1925, 1926.
Days with data per year at Great Falls
YearDays with dataShare of yearComplete
192212233%No
1923364100%Yes
192436499%Yes
192519854%No
192630784%No
1927365100%Yes
1928366100%Yes
1929365100%Yes
1930365100%Yes
1931365100%Yes
193233592%Yes
1933365100%Yes
1934365100%Yes
1935365100%Yes
1936366100%Yes
1937365100%Yes
1938365100%Yes
1939365100%Yes
1940366100%Yes
1941365100%Yes
194236399%Yes
1943365100%Yes
1944366100%Yes
1945365100%Yes
1946365100%Yes
1947364100%Yes
1948366100%Yes
1949365100%Yes
1950365100%Yes
1951365100%Yes
1952366100%Yes
1953365100%Yes
1954364100%Yes
1955365100%Yes
195633692%Yes
1957365100%Yes
1958364100%Yes
1959365100%Yes
1960366100%Yes
1961365100%Yes
1962365100%Yes
1963365100%Yes
1964366100%Yes
1965365100%Yes
1966365100%Yes
1967365100%Yes
1968366100%Yes
1969365100%Yes
1970365100%Yes
1971365100%Yes
1972366100%Yes
1973365100%Yes
1974365100%Yes
1975365100%Yes
1976366100%Yes
197736099%Yes
197836099%Yes
1979365100%Yes
198036499%Yes
198133391%Yes
198233391%Yes
198336399%Yes

Latest Records

20
Latest records at Great Falls
DateStationRecordValueBeat old record byOld record stoodSignificance
22 December 1983Great Falls, CAdaily low max-24.5 C (-12.1 F)3.9 C (7.0 F)37 years22 of 100 (Routine)
18 December 1983Great Falls, CAdaily low max (Tie)-25.0 C (-13.0 F)tie32 years3 of 100 (Routine)
16 December 1983Great Falls, CAdaily low max-23.5 C (-10.3 F)0.2 C (0.4 F)58 years23 of 100 (Routine)
19 November 1983Great Falls, CAdaily high min2.0 C (35.6 F)2.0 C (3.6 F)46 years22 of 100 (Routine)
1 November 1983Great Falls, CAdaily high min9.0 C (48.2 F)3.4 C (6.1 F)36 years20 of 100 (Routine)
23 October 1983Great Falls, CAdaily rain14.0 mm (0.6 in)12.2 mm (0.5 in)2 years20 of 100 (Routine)
27 September 1983Great Falls, CAdaily high min14.5 C (58.1 F)1.7 C (3.1 F)60 years27 of 100 (Routine)
22 September 1983Great Falls, CAdaily low max7.0 C (44.6 F)0.8 C (1.4 F)54 years23 of 100 (Routine)
2 September 1983Great Falls, CAmonthly high max35.5 C (95.9 F)1.6 C (2.9 F)42 years30 of 100 (Routine)
1 September 1983Great Falls, CAmonthly high min22.0 C (71.6 F)0.9 C (1.6 F)34 years27 of 100 (Routine)
17 August 1983Great Falls, CAdaily high max32.0 C (89.6 F)0.9 C (1.6 F)48 years22 of 100 (Routine)
4 August 1983Great Falls, CAdaily high max37.0 C (98.6 F)3.1 C (5.6 F)52 years27 of 100 (Routine)
4 August 1983Great Falls, CAdaily high min22.0 C (71.6 F)0.3 C (0.5 F)36 years16 of 100 (Routine)
15 July 1983Great Falls, CAdaily high min24.5 C (76.1 F)3.4 C (6.1 F)8 years18 of 100 (Routine)
15 July 1983Great Falls, CAdaily high max34.5 C (94.1 F)0.1 C (0.2 F)36 years16 of 100 (Routine)
5 July 1983Great Falls, CAdaily low min5.0 C (41.0 F)0.6 C (1.1 F)48 years21 of 100 (Routine)
4 July 1983Great Falls, CAdaily low max16.0 C (60.8 F)0.1 C (0.2 F)26 years14 of 100 (Routine)
21 June 1983Great Falls, CAdaily rain40.0 mm (1.6 in)20.9 mm (0.8 in)8 years31 of 100 (Routine)
15 June 1983Great Falls, CAdaily low max12.0 C (53.6 F)0.2 C (0.4 F)44 years19 of 100 (Routine)
12 June 1983Great Falls, CAdaily high min18.0 C (64.4 F)0.2 C (0.4 F)32 years15 of 100 (Routine)

Climate Trend

55 complete years, 1923 to 1983
Annual mean temperature at Great Falls as warming stripes, 1923 to 1983 One stripe for each of 55 complete years at Great Falls, 1923 to 1983. Blue stripes are years cooler than the station's own mean of 2.2 C (35.9 F); red stripes are warmer. The coolest year was 1950, at -0.4 C (31.2 F), and the warmest was 1931, at 4.5 C (40.2 F). The strongest colour marks a difference of 2.6 C (4.7 F). 1923: 2.7 C, +0.5 C from the station mean1924: 1.9 C, -0.3 C from the station mean1927: 1.8 C, -0.4 C from the station mean1928: 2.9 C, +0.7 C from the station mean1929: 0.6 C, -1.6 C from the station mean1930: 2.3 C, +0.1 C from the station mean1931: 4.5 C, +2.4 C from the station mean1933: 0.9 C, -1.2 C from the station mean1934: 1.7 C, -0.4 C from the station mean1935: 1.4 C, -0.8 C from the station mean1936: 0.4 C, -1.8 C from the station mean1937: 1.4 C, -0.8 C from the station mean1938: 2.9 C, +0.7 C from the station mean1939: 2.5 C, +0.3 C from the station mean1940: 2.9 C, +0.7 C from the station mean1941: 3.5 C, +1.3 C from the station mean1942: 2.7 C, +0.5 C from the station mean1943: 1.8 C, -0.4 C from the station mean1944: 3.3 C, +1.1 C from the station mean1945: 1.6 C, -0.6 C from the station mean1946: 2.0 C, -0.2 C from the station mean1947: 1.8 C, -0.4 C from the station mean1948: 2.4 C, +0.3 C from the station mean1949: 1.9 C, -0.3 C from the station mean1950: -0.4 C, -2.6 C from the station mean1951: 1.0 C, -1.2 C from the station mean1952: 3.2 C, +1.1 C from the station mean1953: 3.1 C, +1.0 C from the station mean1954: 2.1 C, -0.1 C from the station mean1955: 1.7 C, -0.5 C from the station mean1957: 1.8 C, -0.3 C from the station mean1958: 2.1 C, -0.1 C from the station mean1959: 1.3 C, -0.8 C from the station mean1960: 2.4 C, +0.2 C from the station mean1961: 3.1 C, +1.0 C from the station mean1962: 2.4 C, +0.2 C from the station mean1963: 3.3 C, +1.1 C from the station mean1964: 2.7 C, +0.5 C from the station mean1965: 1.5 C, -0.7 C from the station mean1966: 1.5 C, -0.7 C from the station mean1967: 1.7 C, -0.5 C from the station mean1968: 2.3 C, +0.1 C from the station mean1969: 2.8 C, +0.7 C from the station mean1970: 1.9 C, -0.3 C from the station mean1971: 2.3 C, +0.1 C from the station mean1972: 1.0 C, -1.2 C from the station mean1973: 3.5 C, +1.4 C from the station mean1974: 1.8 C, -0.3 C from the station mean1975: 2.6 C, +0.4 C from the station mean1976: 2.5 C, +0.3 C from the station mean1977: 3.4 C, +1.2 C from the station mean1978: 1.7 C, -0.4 C from the station mean1979: 1.0 C, -1.2 C from the station mean1980: 2.6 C, +0.5 C from the station mean1983: 3.7 C, +1.5 C from the station mean1923193019401950196019701980
One stripe for each of 55 complete years at Great Falls, 1923 to 1983. Blue stripes are years cooler than the station's own mean of 2.2 C (35.9 F); red stripes are warmer. The coolest year was 1950, at -0.4 C (31.2 F), and the warmest was 1931, at 4.5 C (40.2 F). The strongest colour marks a difference of 2.6 C (4.7 F).
Annual mean temperature at Great Falls as warming stripes, 1923 to 1983
YearAnnual mean temperatureDifference from the station mean
19232.7 C+0.51 C
19241.9 C-0.31 C
19271.8 C-0.40 C
19282.9 C+0.68 C
19290.6 C-1.58 C
19302.3 C+0.09 C
19314.5 C+2.37 C
19330.9 C-1.24 C
19341.7 C-0.44 C
19351.4 C-0.75 C
19360.4 C-1.78 C
19371.4 C-0.76 C
19382.9 C+0.75 C
19392.5 C+0.28 C
19402.9 C+0.74 C
19413.5 C+1.34 C
19422.7 C+0.55 C
19431.8 C-0.39 C
19443.3 C+1.10 C
19451.6 C-0.60 C
19462.0 C-0.19 C
19471.8 C-0.39 C
19482.4 C+0.26 C
19491.9 C-0.27 C
1950-0.4 C-2.59 C
19511.0 C-1.15 C
19523.2 C+1.07 C
19533.1 C+0.97 C
19542.1 C-0.06 C
19551.7 C-0.46 C
19571.8 C-0.33 C
19582.1 C-0.05 C
19591.3 C-0.84 C
19602.4 C+0.18 C
19613.1 C+0.97 C
19622.4 C+0.22 C
19633.3 C+1.09 C
19642.7 C+0.54 C
19651.5 C-0.68 C
19661.5 C-0.67 C
19671.7 C-0.49 C
19682.3 C+0.11 C
19692.8 C+0.67 C
19701.9 C-0.27 C
19712.3 C+0.14 C
19721.0 C-1.16 C
19733.5 C+1.36 C
19741.8 C-0.34 C
19752.6 C+0.45 C
19762.5 C+0.33 C
19773.4 C+1.20 C
19781.7 C-0.43 C
19791.0 C-1.16 C
19802.6 C+0.46 C
19833.7 C+1.51 C

The fitted trend in annual mean temperature here over 1923 to 1983 is 0.1 C (-0.1 to 0.2) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.2 to 0.4) per decade. The slope is a straight line fitted to 55 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Great Falls
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.1 C (-0.1 to 0.2) per decade0.1 F (-0.2 to 0.4) per decade1923 to 198355Not clearly different from zero
Mean daily maximum-0.13 C (-0.28 to 0.02) per decade-0.24 F (-0.51 to 0.03) per decade1923 to 198355Not clearly different from zero
Mean daily minimum0.3 C (0.1 to 0.4) per decade0.5 F (0.2 to 0.7) per decade1923 to 198355Rise

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1922 to 1983
Yearly extremes at Great Falls: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)40.0 C (104.0 F)193633.3 C (91.9 F)62
Coldest night (TNn)-45.6 C (-50.1 F)1933-38.9 C (-38.0 F)62
Wettest day (Rx1day)73.9 mm (2.9 in)197335.1 mm (1.4 in)62
Wettest five days (Rx5day)126.0 mm (5.0 in)197452.1 mm (2.1 in)62
Longest dry spell (CDD)54 days197327 days62

Hottest day (TXx)

Hottest day (TXx) at Great Falls by year The hottest day of the year at Great Falls, 1922 to 1983. The record is 40.0 C (104.0 F) in 1936, marked on the chart; the median year is 33.3 C (91.9 F). 25303540194019601980Record: 40.0 C (104.0 F) in 1936
The hottest day of the year at Great Falls, 1922 to 1983. The record is 40.0 C (104.0 F) in 1936, marked on the chart; the median year is 33.3 C (91.9 F).
Hottest day (TXx) at Great Falls by year
YearHottest day (TXx)
192230.6 C (87.1 F)
192336.1 C (97.0 F)
192432.8 C (91.0 F)
192525.6 C (78.1 F)
192634.4 C (93.9 F)
192730.0 C (86.0 F)
192833.3 C (91.9 F)
192932.8 C (91.0 F)
193033.3 C (91.9 F)
193135.0 C (95.0 F)
193233.3 C (91.9 F)
193336.7 C (98.1 F)
193432.2 C (90.0 F)
193532.8 C (91.0 F)
193640.0 C (104.0 F)
193735.6 C (96.1 F)
193833.3 C (91.9 F)
193935.0 C (95.0 F)
194036.7 C (98.1 F)
194136.7 C (98.1 F)
194231.7 C (89.1 F)
194334.4 C (93.9 F)
194432.2 C (90.0 F)
194537.2 C (99.0 F)
194633.9 C (93.0 F)
194736.1 C (97.0 F)
194832.2 C (90.0 F)
194938.9 C (102.0 F)
195032.8 C (91.0 F)
195133.3 C (91.9 F)
195235.0 C (95.0 F)
195333.3 C (91.9 F)
195431.7 C (89.1 F)
195534.4 C (93.9 F)
195635.6 C (96.1 F)
195733.3 C (91.9 F)
195835.0 C (95.0 F)
195932.8 C (91.0 F)
196033.9 C (93.0 F)
196134.4 C (93.9 F)
196233.3 C (91.9 F)
196332.2 C (90.0 F)
196433.9 C (93.0 F)
196532.8 C (91.0 F)
196632.8 C (91.0 F)
196735.0 C (95.0 F)
196830.6 C (87.1 F)
196934.4 C (93.9 F)
197033.3 C (91.9 F)
197133.3 C (91.9 F)
197233.3 C (91.9 F)
197329.4 C (84.9 F)
197433.3 C (91.9 F)
197535.0 C (95.0 F)
197636.7 C (98.1 F)
197731.7 C (89.1 F)
197832.8 C (91.0 F)
197933.3 C (91.9 F)
198036.0 C (96.8 F)
198137.0 C (98.6 F)
198231.0 C (87.8 F)
198337.0 C (98.6 F)

Coldest night (TNn)

Coldest night (TNn) at Great Falls by year The coldest night of the year at Great Falls, 1922 to 1983. The record is -45.6 C (-50.1 F) in 1933, marked on the chart; the median year is -38.9 C (-38.0 F). -50-45-40-35-30194019601980Record: -45.6 C (-50.1 F) in 1933
The coldest night of the year at Great Falls, 1922 to 1983. The record is -45.6 C (-50.1 F) in 1933, marked on the chart; the median year is -38.9 C (-38.0 F).
Coldest night (TNn) at Great Falls by year
YearColdest night (TNn)
1922-35.0 C (-31.0 F)
1923-38.9 C (-38.0 F)
1924-38.9 C (-38.0 F)
1925-40.6 C (-41.1 F)
1926-38.3 C (-36.9 F)
1927-40.0 C (-40.0 F)
1928-37.8 C (-36.0 F)
1929-37.2 C (-35.0 F)
1930-42.8 C (-45.0 F)
1931-33.9 C (-29.0 F)
1932-38.9 C (-38.0 F)
1933-45.6 C (-50.1 F)
1934-45.6 C (-50.1 F)
1935-42.2 C (-44.0 F)
1936-45.6 C (-50.1 F)
1937-41.1 C (-42.0 F)
1938-41.1 C (-42.0 F)
1939-40.6 C (-41.1 F)
1940-39.4 C (-38.9 F)
1941-43.9 C (-47.0 F)
1942-37.2 C (-35.0 F)
1943-45.0 C (-49.0 F)
1944-38.3 C (-36.9 F)
1945-36.1 C (-33.0 F)
1946-38.9 C (-38.0 F)
1947-40.0 C (-40.0 F)
1948-38.9 C (-38.0 F)
1949-42.8 C (-45.0 F)
1950-43.3 C (-45.9 F)
1951-41.7 C (-43.1 F)
1952-36.7 C (-34.1 F)
1953-36.7 C (-34.1 F)
1954-41.1 C (-42.0 F)
1955-43.9 C (-47.0 F)
1956-37.8 C (-36.0 F)
1957-37.8 C (-36.0 F)
1958-38.9 C (-38.0 F)
1959-36.7 C (-34.1 F)
1960-34.4 C (-29.9 F)
1961-35.6 C (-32.1 F)
1962-42.8 C (-45.0 F)
1963-37.8 C (-36.0 F)
1964-34.4 C (-29.9 F)
1965-37.2 C (-35.0 F)
1966-45.6 C (-50.1 F)
1967-40.0 C (-40.0 F)
1968-42.2 C (-44.0 F)
1969-40.0 C (-40.0 F)
1970-38.3 C (-36.9 F)
1971-37.2 C (-35.0 F)
1972-40.0 C (-40.0 F)
1973-38.9 C (-38.0 F)
1974-41.1 C (-42.0 F)
1975-36.7 C (-34.1 F)
1976-34.4 C (-29.9 F)
1977-37.8 C (-36.0 F)
1978-38.3 C (-36.9 F)
1979-40.0 C (-40.0 F)
1980-36.0 C (-32.8 F)
1981-40.0 C (-40.0 F)
1982-38.5 C (-37.3 F)
1983-37.0 C (-34.6 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Great Falls by year The wettest day of the year at Great Falls, 1922 to 1983. The record is 73.9 mm (2.9 in) in 1973, marked on the chart; the median year is 35.1 mm (1.4 in). 020406080194019601980Record: 73.9 mm (2.9 in) in 1973
The wettest day of the year at Great Falls, 1922 to 1983. The record is 73.9 mm (2.9 in) in 1973, marked on the chart; the median year is 35.1 mm (1.4 in).
Wettest day (Rx1day) at Great Falls by year
YearWettest day (Rx1day)
192231.0 mm (1.2 in)
192331.2 mm (1.2 in)
192429.2 mm (1.1 in)
192538.1 mm (1.5 in)
192648.5 mm (1.9 in)
192745.5 mm (1.8 in)
192817.5 mm (0.7 in)
192910.2 mm (0.4 in)
193015.2 mm (0.6 in)
19317.6 mm (0.30 in)
193210.2 mm (0.4 in)
193320.3 mm (0.8 in)
19346.4 mm (0.25 in)
193559.4 mm (2.3 in)
193635.1 mm (1.4 in)
193727.7 mm (1.1 in)
193836.8 mm (1.4 in)
193926.9 mm (1.1 in)
194023.9 mm (0.9 in)
194161.5 mm (2.4 in)
194250.0 mm (2.0 in)
194330.2 mm (1.2 in)
194455.4 mm (2.2 in)
194533.8 mm (1.3 in)
194635.8 mm (1.4 in)
194735.1 mm (1.4 in)
194820.6 mm (0.8 in)
194966.3 mm (2.6 in)
195036.8 mm (1.4 in)
195123.1 mm (0.9 in)
195230.7 mm (1.2 in)
195344.7 mm (1.8 in)
195433.5 mm (1.3 in)
195547.2 mm (1.9 in)
195624.6 mm (1.0 in)
195722.9 mm (0.9 in)
195842.7 mm (1.7 in)
195944.5 mm (1.8 in)
196026.4 mm (1.0 in)
196125.4 mm (1.0 in)
196238.1 mm (1.5 in)
196323.9 mm (0.9 in)
196436.1 mm (1.4 in)
196533.3 mm (1.3 in)
196623.4 mm (0.9 in)
196731.5 mm (1.2 in)
196835.6 mm (1.4 in)
196924.4 mm (1.0 in)
197054.6 mm (2.1 in)
197138.9 mm (1.5 in)
197226.9 mm (1.1 in)
197373.9 mm (2.9 in)
197449.0 mm (1.9 in)
197554.6 mm (2.1 in)
197632.3 mm (1.3 in)
197742.2 mm (1.7 in)
197844.5 mm (1.8 in)
197939.1 mm (1.5 in)
198046.0 mm (1.8 in)
198150.7 mm (2.0 in)
198250.0 mm (2.0 in)
198340.0 mm (1.6 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Great Falls by year The wettest five days of the year at Great Falls, 1922 to 1983. The record is 126.0 mm (5.0 in) in 1974, marked on the chart; the median year is 52.1 mm (2.1 in). 050100150194019601980Record: 126.0 mm (5.0 in) in 1974
The wettest five days of the year at Great Falls, 1922 to 1983. The record is 126.0 mm (5.0 in) in 1974, marked on the chart; the median year is 52.1 mm (2.1 in).
Wettest five days (Rx5day) at Great Falls by year
YearWettest five days (Rx5day)
192242.7 mm (1.7 in)
192351.8 mm (2.0 in)
192436.0 mm (1.4 in)
192538.9 mm (1.5 in)
192668.6 mm (2.7 in)
192782.6 mm (3.3 in)
192817.8 mm (0.7 in)
192913.9 mm (0.5 in)
193029.2 mm (1.1 in)
19319.7 mm (0.38 in)
193216.6 mm (0.7 in)
193321.6 mm (0.9 in)
193415.8 mm (0.6 in)
193583.6 mm (3.3 in)
193642.7 mm (1.7 in)
193734.1 mm (1.3 in)
193842.6 mm (1.7 in)
193975.7 mm (3.0 in)
194030.4 mm (1.2 in)
1941124.5 mm (4.9 in)
194265.5 mm (2.6 in)
194347.7 mm (1.9 in)
194481.8 mm (3.2 in)
194559.1 mm (2.3 in)
194652.4 mm (2.1 in)
194773.8 mm (2.9 in)
194849.0 mm (1.9 in)
194971.4 mm (2.8 in)
195068.2 mm (2.7 in)
195133.3 mm (1.3 in)
195231.7 mm (1.2 in)
195354.1 mm (2.1 in)
195440.6 mm (1.6 in)
195582.7 mm (3.3 in)
195665.8 mm (2.6 in)
195729.0 mm (1.1 in)
195857.9 mm (2.3 in)
195965.5 mm (2.6 in)
196046.8 mm (1.8 in)
196139.4 mm (1.6 in)
196258.9 mm (2.3 in)
196340.5 mm (1.6 in)
196453.6 mm (2.1 in)
196561.0 mm (2.4 in)
196643.2 mm (1.7 in)
196739.6 mm (1.6 in)
196858.6 mm (2.3 in)
196937.3 mm (1.5 in)
197065.5 mm (2.6 in)
197151.3 mm (2.0 in)
197239.6 mm (1.6 in)
197382.7 mm (3.3 in)
1974126.0 mm (5.0 in)
197580.3 mm (3.2 in)
197659.9 mm (2.4 in)
197749.3 mm (1.9 in)
197866.6 mm (2.6 in)
197961.7 mm (2.4 in)
198047.6 mm (1.9 in)
198168.4 mm (2.7 in)
198262.4 mm (2.5 in)
198378.6 mm (3.1 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Great Falls by year The longest dry spell of the year at Great Falls, 1922 to 1983. The record is 54 days in 1973, marked on the chart; the median year is 27 days. 0204060194019601980Record: 54 days in 1973
The longest dry spell of the year at Great Falls, 1922 to 1983. The record is 54 days in 1973, marked on the chart; the median year is 27 days.
Longest dry spell (CDD) at Great Falls by year
YearLongest dry spell (CDD)
192220 days
192323 days
192420 days
192524 days
192639 days
192736 days
192848 days
192917 days
193023 days
193127 days
193249 days
193315 days
193428 days
193529 days
193620 days
193714 days
193824 days
193942 days
194030 days
194120 days
194220 days
194323 days
194441 days
194523 days
194618 days
194716 days
194831 days
194920 days
195013 days
195118 days
195219 days
195325 days
195424 days
195536 days
195632 days
195732 days
195826 days
195921 days
196037 days
196125 days
196226 days
196327 days
196423 days
196527 days
196626 days
196727 days
196841 days
196948 days
197040 days
197115 days
197223 days
197354 days
197424 days
197530 days
197653 days
197728 days
197841 days
197927 days
198033 days
198148 days
198232 days
198339 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

55 years with a frost

Across 55 years with a frost, the median last spring frost at Great Falls falls on 18 May and the median first autumn frost on 25 September, which leaves a median of 130 days between them.

Fitted over all years, the growing season changes by +0.3 days per decade at this station.

Frost dates and growing season at Great Falls
MeasureMedian, all yearsEarliest periodRecent period (1951 to 1983)Recent against earliestFitted trend
Last spring frost18 Mayn/a17 Mayn/a-1.0 days per decade
First autumn frost25 Septembern/a24 Septembern/a-0.7 days per decade
Growing days130 daysn/a128 daysn/a+0.3 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

50 years, 1925 to 1983

A day with at least 36.4 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 75.8 mm (3.0 in) of rain is expected about once in 100 years.

Rainfall return levels at Great Falls: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years36.4 mm (1.4 in)
5 years47.5 mm (1.9 in)
10 years54.6 mm (2.1 in)
25 years63.3 mm (2.5 in)
50 years69.6 mm (2.7 in)
100 years75.8 mm (3.0 in)Longer than the 50 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 50 years of values from 1925 to 1983.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 73.9 mm (2.9 in) in 1973; 66.3 mm (2.6 in) in 1949; 61.5 mm (2.4 in) in 1941.

Station Changes

2 suspected

2 changes were suspected in the annual mean temperature of Great Falls, at 1930 and 1960. Each is measured against neighbouring stations.

  • Relative to 5 neighbouring stations, the station's annual mean temperature from 1930 ran 0.7 C (1.3 F) lower than in the years before (likely change).
  • Relative to 5 neighbouring stations, the station's annual mean temperature from 1960 ran 0.4 C (0.7 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Great Falls, against neighbouring stations
YearShift (C)Shift (F)StrengthNeighbours
1930-0.7-1.3likely5
1960+0.4+0.7likely5

Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.

Download the Data

  • Data for Great Falls standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Great Falls threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-14 (14 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-14).