Built 2026-10-17 (17 October 2026)

Summit Weather Records (USC00247978)

Record envelope, standing records and threshold days for Summit (USC00247978), Montana, United States, with 124 years of record.

Key Facts for Summit

  • Summit (USC00247978) is a weather station in Montana, United States at 48.32 latitude and -113.35 longitude, 1,595 m (5,233 ft) above sea level.
  • The station reports from 1903 to 2026, 124 years of record.
  • 1,464 records set at Summit still stand.
  • Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Summit set a daily record high maximum temperature of 30.6 C (87.1 F) on 27 August 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

  • Location: Montana, United States, 48.32 latitude, -113.35 longitude.
  • Elevation: 1,595 m (5,233 ft).
  • Period of record: 1903 to 2026, 124 years.
  • Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

10 days at or beyond a record
Daily record high and record low at Summit, with 2026 drawn through them The band shows the record high and record low for each calendar day at Summit. The lines show the 2026 daily maximum and minimum. 10 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 Summit. The lines show the 2026 daily maximum and minimum. 10 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Summit, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan12.2 C (54.0 F)-47.2 C (-53.0 F)8.3 C (46.9 F)-20.6 C (-5.1 F)
Feb13.3 C (55.9 F)-47.2 C (-53.0 F)13.3 C (55.9 F)-25.6 C (-14.1 F)
Mar16.7 C (62.1 F)-41.1 C (-42.0 F)12.8 C (55.0 F)-20.0 C (-4.0 F)
Apr25.6 C (78.1 F)-34.4 C (-29.9 F)22.8 C (73.0 F)-11.1 C (12.0 F)
May27.2 C (81.0 F)-17.8 C (0.0 F)26.7 C (80.1 F)-4.4 C (24.1 F)
Jun33.3 C (91.9 F)-9.4 C (15.1 F)23.9 C (75.0 F)-1.7 C (28.9 F)
Jul33.9 C (93.0 F)-5.6 C (21.9 F)31.1 C (88.0 F)1.7 C (35.1 F)
Aug35.6 C (96.1 F)-7.2 C (19.0 F)30.6 C (87.1 F)-1.1 C (30.0 F)
Sep33.3 C (91.9 F)-14.4 C (6.1 F)27.2 C (81.0 F)-3.9 C (25.0 F)
Oct27.8 C (82.0 F)-34.4 C (-29.9 F)21.7 C (71.1 F)-4.4 C (24.1 F)
Nov17.8 C (64.0 F)-39.4 C (-38.9 F)n/an/a
Dec13.9 C (57.0 F)-43.3 C (-45.9 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Summit by the year they were set 1,464 records at Summit still stand. 1936 holds the most, with 67. 0204060801903: 231935: 331936: 671937: 221938: 241939: 571940: 401941: 241942: 241943: 321944: 211945: 181946: 201947: 241948: 261949: 321950: 421951: 361952: 221953: 251954: 361955: 441956: 241957: 281958: 241959: 251960: 431961: 371962: 331963: 221964: 231965: 291966: 321967: 351968: 431969: 261970: 261971: 241972: 321973: 341974: 101975: 291976: 211977: 131978: 141979: 42018: 102019: 102020: 92021: 262022: 152023: 212024: 142025: 202026: 161903194019461952195819641970197620202026
1,464 records at Summit still stand. 1936 holds the most, with 67.
Standing records at Summit by the year they were set
Year setStanding records
190323
193533
193667
193722
193824
193957
194040
194124
194224
194332
194421
194518
194620
194724
194826
194932
195042
195136
195222
195325
195436
195544
195624
195728
195824
195925
196043
196137
196233
196322
196423
196529
196632
196735
196843
196926
197026
197124
197232
197334
197410
197529
197621
197713
197814
19794
201810
201910
20209
202126
202215
202321
202414
202520
202616

All-Time Record Progression

8 new records
When Summit set new all-time records 8 all-time records were set at Summit between 20 January 1972 and 24 February 1979. Each dot is a new record. Record daily snowfallRecord snow depth20 January 1972: Record daily snowfall 111.8 cm (44.0 in)1 February 1972: Record snow depth 482.6 cm (190.0 in)12 February 1979: Record snow depth 487.7 cm (192.0 in)13 February 1979: Record snow depth 497.8 cm (196.0 in)14 February 1979: Record snow depth 505.5 cm (199.0 in)20 February 1979: Record snow depth 508.0 cm (200.0 in)21 February 1979: Record snow depth 513.1 cm (202.0 in)24 February 1979: Record snow depth 515.6 cm (203.0 in)19751980
8 all-time records were set at Summit between 20 January 1972 and 24 February 1979. Each dot is a new record.
When Summit set new all-time records
DateKindDetail
1972-01-20Record daily snowfallRecord daily snowfall 111.8 cm (44.0 in)
1972-02-01Record snow depthRecord snow depth 482.6 cm (190.0 in)
1979-02-12Record snow depthRecord snow depth 487.7 cm (192.0 in)
1979-02-13Record snow depthRecord snow depth 497.8 cm (196.0 in)
1979-02-14Record snow depthRecord snow depth 505.5 cm (199.0 in)
1979-02-20Record snow depthRecord snow depth 508.0 cm (200.0 in)
1979-02-21Record snow depthRecord snow depth 513.1 cm (202.0 in)
1979-02-24Record snow depthRecord snow depth 515.6 cm (203.0 in)

Wettest Day of Each Month

Jun: 185.7 mm (7.3 in)
Record daily precipitation for each month at Summit The wettest day on record for each calendar month at Summit. The most was 185.7 mm (7.3 in) on 8 June 1964. 050100150200 Jan: 74.9 mm (2.9 in), 9 January 1953 Jan Feb: 63.5 mm (2.5 in), 11 February 1961 Feb Mar: 36.8 mm (1.4 in), 31 March 1945 Mar Apr: 49.8 mm (2.0 in), 30 April 1951 Apr May: 64.8 mm (2.6 in), 2 May 1964 May Jun: 185.7 mm (7.3 in), 8 June 1964 Jun Jul: 39.4 mm (1.6 in), 19 July 1972 Jul Aug: 50.8 mm (2.0 in), 2 August 1972 Aug Sep: 37.1 mm (1.5 in), 14 September 1940 Sep Oct: 39.4 mm (1.6 in), 29 October 1951 Oct Nov: 45.5 mm (1.8 in), 23 November 1942 Nov Dec: 59.2 mm (2.3 in), 11 December 2025 Dec
The wettest day on record for each calendar month at Summit. The most was 185.7 mm (7.3 in) on 8 June 1964.
Record daily precipitation for each month at Summit
MonthRecord daily precipitation (mm)Date
Jan74.9 mm (2.9 in)9 January 1953
Feb63.5 mm (2.5 in)11 February 1961
Mar36.8 mm (1.4 in)31 March 1945
Apr49.8 mm (2.0 in)30 April 1951
May64.8 mm (2.6 in)2 May 1964
Jun185.7 mm (7.3 in)8 June 1964
Jul39.4 mm (1.6 in)19 July 1972
Aug50.8 mm (2.0 in)2 August 1972
Sep37.1 mm (1.5 in)14 September 1940
Oct39.4 mm (1.6 in)29 October 1951
Nov45.5 mm (1.8 in)23 November 1942
Dec59.2 mm (2.3 in)11 December 2025

Period of Record Coverage

1903 to 2026
Days with data per year at Summit 55 years of record at Summit, 1903 to 2026. 10 years have data for under 90 percent of days and are left out of rankings: 1903, 1945, 1953, 1956, 1966, 1968, 1977, 1978 and others. 1903: 258 of 365 days1935: 334 of 365 days1936: 366 of 366 days1937: 364 of 365 days1938: 364 of 365 days1939: 365 of 365 days1940: 363 of 366 days1941: 363 of 365 days1942: 365 of 365 days1943: 364 of 365 days1944: 365 of 366 days1945: 309 of 365 days1946: 341 of 365 days1947: 360 of 365 days1948: 364 of 366 days1949: 362 of 365 days1950: 361 of 365 days1951: 356 of 365 days1952: 366 of 366 days1953: 305 of 365 days1954: 359 of 365 days1955: 363 of 365 days1956: 321 of 366 days1957: 348 of 365 days1958: 361 of 365 days1959: 358 of 365 days1960: 365 of 366 days1961: 363 of 365 days1962: 361 of 365 days1963: 364 of 365 days1964: 357 of 366 days1965: 358 of 365 days1966: 325 of 365 days1967: 352 of 365 days1968: 299 of 366 days1969: 363 of 365 days1970: 364 of 365 days1971: 354 of 365 days1972: 356 of 366 days1973: 364 of 365 days1974: 332 of 365 days1975: 363 of 365 days1976: 365 of 366 days1977: 303 of 365 days1978: 271 of 365 days1979: 119 of 365 days2018: 349 of 365 days2019: 330 of 365 days2020: 351 of 366 days2021: 346 of 365 days2022: 340 of 365 days2023: 354 of 365 days2024: 352 of 366 days2025: 345 of 365 days2026: 275 of 365 days19401950196019702020
55 years of record at Summit, 1903 to 2026. 10 years have data for under 90 percent of days and are left out of rankings: 1903, 1945, 1953, 1956, 1966, 1968, 1977, 1978 and others.
Days with data per year at Summit
YearDays with dataShare of yearComplete
190325871%No
193533492%Yes
1936366100%Yes
1937364100%Yes
1938364100%Yes
1939365100%Yes
194036399%Yes
194136399%Yes
1942365100%Yes
1943364100%Yes
1944365100%Yes
194530985%No
194634193%Yes
194736099%Yes
194836499%Yes
194936299%Yes
195036199%Yes
195135698%Yes
1952366100%Yes
195330584%No
195435998%Yes
195536399%Yes
195632188%No
195734895%Yes
195836199%Yes
195935898%Yes
1960365100%Yes
196136399%Yes
196236199%Yes
1963364100%Yes
196435798%Yes
196535898%Yes
196632589%No
196735296%Yes
196829982%No
196936399%Yes
1970364100%Yes
197135497%Yes
197235697%Yes
1973364100%Yes
197433291%Yes
197536399%Yes
1976365100%Yes
197730383%No
197827174%No
197911933%No
201834996%Yes
201933090%Yes
202035196%Yes
202134695%Yes
202234093%Yes
202335497%Yes
202435296%Yes
202534595%Yes
202627575%No

Latest Records

20
Latest records at Summit
DateStationRecordValueBeat old record byOld record stoodSignificance
27 August 2026Summit, USdaily high max (Provisional)30.6 C (87.1 F)0.6 C (1.1 F)55 years27 of 100 (Routine)
27 July 2026Summit, USdaily high min13.9 C (57.0 F)1.7 C (3.1 F)72 years35 of 100 (Notable)
26 July 2026Summit, USdaily high max31.1 C (88.0 F)2.2 C (4.0 F)67 years34 of 100 (Routine)
19 July 2026Summit, USdaily high min15.0 C (59.0 F)2.8 C (5.0 F)71 years38 of 100 (Notable)
17 July 2026Summit, USdaily high max (Tie)30.6 C (87.1 F)tie89 years9 of 100 (Routine)
30 May 2026Summit, USdaily high min (Tie)8.3 C (46.9 F)tie3 years2 of 100 (Routine)
11 April 2026Summit, USdaily high max16.7 C (62.1 F)0.6 C (1.1 F)3 years11 of 100 (Routine)
7 April 2026Summit, USdaily high max (Tie)15.0 C (59.0 F)tie48 years6 of 100 (Routine)
20 March 2026Summit, USdaily high min (Tie)4.4 C (39.9 F)tie87 years9 of 100 (Routine)
19 March 2026Summit, USdaily high min (Tie)3.9 C (39.0 F)tie87 years9 of 100 (Routine)
18 March 2026Summit, USdaily high min3.9 C (39.0 F)3.3 C (5.9 F)53 years30 of 100 (Routine)
17 March 2026Summit, USdaily rain29.0 mm (1.1 in)12.5 mm (0.5 in)52 years50 of 100 (Notable)
12 March 2026Summit, USdaily rain23.4 mm (0.9 in)8.2 mm (0.32 in)61 years20 of 100 (Routine)
16 February 2026Summit, USdaily high min (Tie)-2.8 C (27.0 F)tie76 years8 of 100 (Routine)
8 February 2026Summit, USdaily high min1.7 C (35.1 F)1.7 C (3.1 F)80 years35 of 100 (Notable)
7 February 2026Summit, USdaily high max10.6 C (51.1 F)1.7 C (3.1 F)72 years33 of 100 (Routine)
6 February 2026Summit, USmonthly high max (Tie)13.3 C (55.9 F)tie67 years10 of 100 (Routine)
5 February 2026Summit, USdaily high min3.9 C (39.0 F)4.5 C (8.1 F)63 years33 of 100 (Routine)
5 February 2026Summit, USdaily high max8.9 C (48.0 F)1.1 C (2.0 F)63 years29 of 100 (Routine)
15 January 2026Summit, USdaily high min2.2 C (36.0 F)0.5 C (0.9 F)88 years36 of 100 (Notable)

Climate Trend

39 complete years, 1936 to 2024
Annual mean temperature at Summit as warming stripes, 1936 to 2024 One stripe for each of 39 complete years at Summit, 1936 to 2024. Blue stripes are years cooler than the station's own mean of 2.3 C (36.2 F); red stripes are warmer. The coolest year was 1951, at 0.4 C (32.6 F), and the warmest was 2024, at 4.7 C (40.5 F). The strongest colour marks a difference of 2.5 C (4.5 F). 1936: 1.9 C, -0.4 C from the station mean1937: 1.1 C, -1.3 C from the station mean1938: 2.6 C, +0.3 C from the station mean1939: 3.5 C, +1.1 C from the station mean1940: 3.0 C, +0.7 C from the station mean1941: 3.0 C, +0.7 C from the station mean1942: 2.3 C, -0.1 C from the station mean1943: 1.9 C, -0.4 C from the station mean1944: 2.2 C, -0.1 C from the station mean1947: 2.6 C, +0.3 C from the station mean1948: 1.5 C, -0.8 C from the station mean1949: 1.6 C, -0.8 C from the station mean1950: 0.8 C, -1.6 C from the station mean1951: 0.4 C, -2.0 C from the station mean1952: 2.8 C, +0.4 C from the station mean1954: 2.0 C, -0.4 C from the station mean1955: 1.1 C, -1.2 C from the station mean1957: 2.0 C, -0.3 C from the station mean1958: 3.1 C, +0.8 C from the station mean1959: 2.0 C, -0.4 C from the station mean1960: 2.5 C, +0.1 C from the station mean1961: 3.0 C, +0.6 C from the station mean1962: 1.8 C, -0.5 C from the station mean1963: 3.1 C, +0.8 C from the station mean1964: 1.7 C, -0.6 C from the station mean1965: 1.3 C, -1.1 C from the station mean1967: 2.3 C, 0.0 C from the station mean1969: 2.1 C, -0.2 C from the station mean1970: 1.9 C, -0.5 C from the station mean1971: 1.4 C, -1.0 C from the station mean1972: 2.1 C, -0.2 C from the station mean1973: 2.1 C, -0.3 C from the station mean1975: 0.7 C, -1.7 C from the station mean1976: 3.4 C, +1.1 C from the station mean2018: 3.2 C, +0.9 C from the station mean2020: 4.1 C, +1.8 C from the station mean2022: 4.1 C, +1.7 C from the station mean2023: 4.5 C, +2.2 C from the station mean2024: 4.7 C, +2.4 C from the station mean1936194019501960197019801990200020102020
One stripe for each of 39 complete years at Summit, 1936 to 2024. Blue stripes are years cooler than the station's own mean of 2.3 C (36.2 F); red stripes are warmer. The coolest year was 1951, at 0.4 C (32.6 F), and the warmest was 2024, at 4.7 C (40.5 F). The strongest colour marks a difference of 2.5 C (4.5 F).
Annual mean temperature at Summit as warming stripes, 1936 to 2024
YearAnnual mean temperatureDifference from the station mean
19361.9 C-0.44 C
19371.1 C-1.27 C
19382.6 C+0.25 C
19393.5 C+1.14 C
19403.0 C+0.70 C
19413.0 C+0.65 C
19422.3 C-0.07 C
19431.9 C-0.42 C
19442.2 C-0.11 C
19472.6 C+0.27 C
19481.5 C-0.82 C
19491.6 C-0.76 C
19500.8 C-1.57 C
19510.4 C-1.99 C
19522.8 C+0.44 C
19542.0 C-0.36 C
19551.1 C-1.20 C
19572.0 C-0.32 C
19583.1 C+0.77 C
19592.0 C-0.39 C
19602.5 C+0.12 C
19613.0 C+0.64 C
19621.8 C-0.50 C
19633.1 C+0.77 C
19641.7 C-0.65 C
19651.3 C-1.08 C
19672.3 C-0.05 C
19692.1 C-0.24 C
19701.9 C-0.47 C
19711.4 C-0.96 C
19722.1 C-0.22 C
19732.1 C-0.26 C
19750.7 C-1.66 C
19763.4 C+1.05 C
20183.2 C+0.88 C
20204.1 C+1.80 C
20224.1 C+1.71 C
20234.5 C+2.18 C
20244.7 C+2.40 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1936 to 2024. In Fahrenheit: 0.4 F (0.2 to 0.6) per decade. The slope is a straight line fitted to 39 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Summit
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.2 C (0.1 to 0.3) per decade0.4 F (0.2 to 0.6) per decade1936 to 202439Rise
Mean daily maximum0.14 C (0.02 to 0.27) per decade0.26 F (0.03 to 0.49) per decade1936 to 202439Rise
Mean daily minimum0.3 C (0.2 to 0.4) per decade0.6 F (0.4 to 0.8) per decade1936 to 202439Rise

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

1903 to 2026
Yearly extremes at Summit: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)35.6 C (96.1 F)196131.1 C (88.0 F)55
Coldest night (TNn)-47.2 C (-53.0 F)1936-36.1 C (-33.0 F)56
Wettest day (Rx1day)185.7 mm (7.3 in)196438.1 mm (1.5 in)49
Wettest five days (Rx5day)205.5 mm (8.1 in)196475.7 mm (3.0 in)48
Longest dry spell (CDD)44 days195519 days49

Hottest day (TXx)

Hottest day (TXx) at Summit by year The hottest day of the year at Summit, 1903 to 2026. The record is 35.6 C (96.1 F) in 1961, marked on the chart; the median year is 31.1 C (88.0 F). 152025303540192019401960198020002020Record: 35.6 C (96.1 F) in 1961
The hottest day of the year at Summit, 1903 to 2026. The record is 35.6 C (96.1 F) in 1961, marked on the chart; the median year is 31.1 C (88.0 F).
Hottest day (TXx) at Summit by year
YearHottest day (TXx)
190328.9 C (84.0 F)
193532.2 C (90.0 F)
193632.2 C (90.0 F)
193729.4 C (84.9 F)
193829.4 C (84.9 F)
193932.2 C (90.0 F)
194034.4 C (93.9 F)
194131.1 C (88.0 F)
194229.4 C (84.9 F)
194328.9 C (84.0 F)
194428.9 C (84.0 F)
194530.0 C (86.0 F)
194631.1 C (88.0 F)
194731.1 C (88.0 F)
194828.3 C (82.9 F)
194932.2 C (90.0 F)
195032.8 C (91.0 F)
195131.1 C (88.0 F)
195228.3 C (82.9 F)
195332.2 C (90.0 F)
195430.0 C (86.0 F)
195532.2 C (90.0 F)
195629.4 C (84.9 F)
195728.9 C (84.0 F)
195829.4 C (84.9 F)
195932.2 C (90.0 F)
196033.9 C (93.0 F)
196135.6 C (96.1 F)
196227.8 C (82.0 F)
196331.1 C (88.0 F)
196429.4 C (84.9 F)
196529.4 C (84.9 F)
196631.1 C (88.0 F)
196733.3 C (91.9 F)
196831.1 C (88.0 F)
196935.6 C (96.1 F)
197030.0 C (86.0 F)
197131.7 C (89.1 F)
197229.4 C (84.9 F)
197331.1 C (88.0 F)
197430.6 C (87.1 F)
197530.6 C (87.1 F)
197628.3 C (82.9 F)
197730.0 C (86.0 F)
197832.2 C (90.0 F)
197915.6 C (60.1 F)
2017n/a
201835.0 C (95.0 F)
201932.2 C (90.0 F)
202030.6 C (87.1 F)
202133.3 C (91.9 F)
202232.2 C (90.0 F)
202333.3 C (91.9 F)
202432.8 C (91.0 F)
202530.6 C (87.1 F)
202631.1 C (88.0 F)

Coldest night (TNn)

Coldest night (TNn) at Summit by year The coldest night of the year at Summit, 1903 to 2026. The record is -47.2 C (-53.0 F) in 1936, marked on the chart; the median year is -36.1 C (-33.0 F). -50-40-30-20192019401960198020002020Record: -47.2 C (-53.0 F) in 1936
The coldest night of the year at Summit, 1903 to 2026. The record is -47.2 C (-53.0 F) in 1936, marked on the chart; the median year is -36.1 C (-33.0 F).
Coldest night (TNn) at Summit by year
YearColdest night (TNn)
1903-30.6 C (-23.1 F)
1935-34.4 C (-29.9 F)
1936-47.2 C (-53.0 F)
1937-40.6 C (-41.1 F)
1938-43.9 C (-47.0 F)
1939-43.9 C (-47.0 F)
1940-39.4 C (-38.9 F)
1941-28.9 C (-20.0 F)
1942-40.6 C (-41.1 F)
1943-47.2 C (-53.0 F)
1944-33.3 C (-27.9 F)
1945-41.1 C (-42.0 F)
1946-27.8 C (-18.0 F)
1947-35.6 C (-32.1 F)
1948-40.6 C (-41.1 F)
1949-42.2 C (-44.0 F)
1950-42.8 C (-45.0 F)
1951-40.0 C (-40.0 F)
1952-36.1 C (-33.0 F)
1953-29.4 C (-20.9 F)
1954-47.2 C (-53.0 F)
1955-39.4 C (-38.9 F)
1956-41.7 C (-43.1 F)
1957-33.3 C (-27.9 F)
1958-30.0 C (-22.0 F)
1959-39.4 C (-38.9 F)
1960-41.1 C (-42.0 F)
1961-41.7 C (-43.1 F)
1962-41.7 C (-43.1 F)
1963-42.8 C (-45.0 F)
1964-37.8 C (-36.0 F)
1965-40.6 C (-41.1 F)
1966-35.6 C (-32.1 F)
1967-30.6 C (-23.1 F)
1968-43.3 C (-45.9 F)
1969-35.6 C (-32.1 F)
1970-36.1 C (-33.0 F)
1971-34.4 C (-29.9 F)
1972-41.1 C (-42.0 F)
1973-38.3 C (-36.9 F)
1974-26.1 C (-15.0 F)
1975-41.1 C (-42.0 F)
1976-37.2 C (-35.0 F)
1977-27.2 C (-17.0 F)
1978-31.7 C (-25.1 F)
1979-32.2 C (-26.0 F)
2017-22.2 C (-8.0 F)
2018-25.6 C (-14.1 F)
2019-25.6 C (-14.1 F)
2020-28.3 C (-18.9 F)
2021-25.0 C (-13.0 F)
2022-28.3 C (-18.9 F)
2023-28.9 C (-20.0 F)
2024-29.4 C (-20.9 F)
2025-27.2 C (-17.0 F)
2026-25.6 C (-14.1 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Summit by year The wettest day of the year at Summit, 1903 to 2026. The record is 185.7 mm (7.3 in) in 1964, marked on the chart; the median year is 38.1 mm (1.5 in). 050100150200192019401960198020002020Record: 185.7 mm (7.3 in) in 1964
The wettest day of the year at Summit, 1903 to 2026. The record is 185.7 mm (7.3 in) in 1964, marked on the chart; the median year is 38.1 mm (1.5 in).
Wettest day (Rx1day) at Summit by year
YearWettest day (Rx1day)
190366.0 mm (2.6 in)
193538.1 mm (1.5 in)
193625.7 mm (1.0 in)
193736.3 mm (1.4 in)
193847.0 mm (1.9 in)
193919.6 mm (0.8 in)
194037.1 mm (1.5 in)
194134.8 mm (1.4 in)
194245.5 mm (1.8 in)
194357.4 mm (2.3 in)
194431.0 mm (1.2 in)
194536.8 mm (1.4 in)
194644.2 mm (1.7 in)
194738.6 mm (1.5 in)
194830.7 mm (1.2 in)
194941.7 mm (1.6 in)
195041.1 mm (1.6 in)
195151.8 mm (2.0 in)
195232.3 mm (1.3 in)
195374.9 mm (2.9 in)
195435.6 mm (1.4 in)
195536.8 mm (1.4 in)
195632.5 mm (1.3 in)
195736.1 mm (1.4 in)
195829.2 mm (1.1 in)
195927.9 mm (1.1 in)
196040.6 mm (1.6 in)
196163.5 mm (2.5 in)
196231.8 mm (1.3 in)
196336.8 mm (1.4 in)
1964185.7 mm (7.3 in)
196543.2 mm (1.7 in)
196650.8 mm (2.0 in)
196749.3 mm (1.9 in)
196857.2 mm (2.3 in)
196953.3 mm (2.1 in)
197056.1 mm (2.2 in)
197147.0 mm (1.9 in)
197267.3 mm (2.6 in)
197322.9 mm (0.9 in)
197438.1 mm (1.5 in)
197594.0 mm (3.7 in)
197626.7 mm (1.1 in)
197725.4 mm (1.0 in)
197828.2 mm (1.1 in)
197938.1 mm (1.5 in)
2017n/a
20180.0 mm (0.00 in)
2019n/a
2020n/a
2021n/a
2022n/a
2023n/a
2024n/a
202559.2 mm (2.3 in)
202629.0 mm (1.1 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Summit by year The wettest five days of the year at Summit, 1903 to 2026. The record is 205.5 mm (8.1 in) in 1964, marked on the chart; the median year is 75.7 mm (3.0 in). 050100150200250192019401960198020002020Record: 205.5 mm (8.1 in) in 1964
The wettest five days of the year at Summit, 1903 to 2026. The record is 205.5 mm (8.1 in) in 1964, marked on the chart; the median year is 75.7 mm (3.0 in).
Wettest five days (Rx5day) at Summit by year
YearWettest five days (Rx5day)
1903101.5 mm (4.0 in)
193549.0 mm (1.9 in)
193661.0 mm (2.4 in)
193789.9 mm (3.5 in)
193881.2 mm (3.2 in)
193972.8 mm (2.9 in)
194080.1 mm (3.2 in)
194166.2 mm (2.6 in)
194265.5 mm (2.6 in)
194377.0 mm (3.0 in)
194453.6 mm (2.1 in)
194573.9 mm (2.9 in)
194693.6 mm (3.7 in)
194772.9 mm (2.9 in)
194873.5 mm (2.9 in)
194986.4 mm (3.4 in)
1950104.6 mm (4.1 in)
195178.7 mm (3.1 in)
195249.6 mm (2.0 in)
1953169.5 mm (6.7 in)
195465.3 mm (2.6 in)
195590.7 mm (3.6 in)
195669.6 mm (2.7 in)
195766.5 mm (2.6 in)
195873.9 mm (2.9 in)
195969.9 mm (2.8 in)
196077.9 mm (3.1 in)
1961113.1 mm (4.5 in)
196255.9 mm (2.2 in)
196368.6 mm (2.7 in)
1964205.5 mm (8.1 in)
196576.3 mm (3.0 in)
196669.8 mm (2.7 in)
196775.3 mm (3.0 in)
196876.0 mm (3.0 in)
1969111.0 mm (4.4 in)
197084.9 mm (3.3 in)
1971104.6 mm (4.1 in)
1972152.9 mm (6.0 in)
197368.6 mm (2.7 in)
1974101.6 mm (4.0 in)
1975190.5 mm (7.5 in)
197660.6 mm (2.4 in)
197745.7 mm (1.8 in)
197862.7 mm (2.5 in)
1979106.7 mm (4.2 in)
2017n/a
2018n/a
2019n/a
2020n/a
2021n/a
2022n/a
2023n/a
2024n/a
2025127.5 mm (5.0 in)
202650.6 mm (2.0 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Summit by year The longest dry spell of the year at Summit, 1903 to 2026. The record is 44 days in 1955, marked on the chart; the median year is 19 days. 0204060192019401960198020002020Record: 44 days in 1955
The longest dry spell of the year at Summit, 1903 to 2026. The record is 44 days in 1955, marked on the chart; the median year is 19 days.
Longest dry spell (CDD) at Summit by year
YearLongest dry spell (CDD)
190316 days
193516 days
193613 days
193714 days
193819 days
193918 days
194025 days
194120 days
194220 days
194318 days
194425 days
194521 days
194619 days
194712 days
194828 days
194926 days
195021 days
195128 days
195223 days
195327 days
195414 days
195544 days
195615 days
195724 days
195813 days
195937 days
196031 days
196126 days
196214 days
196341 days
196414 days
196514 days
196612 days
196731 days
196815 days
196931 days
197031 days
197119 days
197214 days
197337 days
197422 days
197517 days
197622 days
197722 days
197813 days
197915 days
2017n/a
20181 day
2019n/a
2020n/a
2021n/a
2022n/a
2023n/a
2024n/a
202511 days
20264 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

39 years with a frost

Across 39 years with a frost, the median last spring frost at Summit falls on 23 June and the median first autumn frost on 7 July, which leaves a median of 14 days between them.

Fitted over all years, the growing season changes by +8.0 days per decade at this station.

Frost dates and growing season at Summit
MeasureMedian, all yearsEarliest periodRecent period (1947 to 2024)Recent against earliestFitted trend
Last spring frost23 Junen/a24 Junen/a-0.8 days per decade
First autumn frost7 Julyn/a5 Julyn/a+7.2 days per decade
Growing days14 daysn/a14 daysn/a+8.0 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

40 years, 1935 to 1976

A day with at least 37.8 mm (1.5 in) of rain is expected about once in 2 years. A day with at least 147.9 mm (5.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Summit: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years37.8 mm (1.5 in)
5 years52.7 mm (2.1 in)
10 years66.7 mm (2.6 in)
25 years91.1 mm (3.6 in)
50 years115.9 mm (4.6 in)Longer than the 40 years of record
100 years147.9 mm (5.8 in)Longer than the 40 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, 40 years of values from 1935 to 1976.

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: 185.7 mm (7.3 in) in 1964; 94.0 mm (3.7 in) in 1975; 67.3 mm (2.6 in) in 1972.

Download the Data

  • Data for Summit standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Summit 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-15).