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Alta Weather Records (USC00130173)

Record envelope, standing records and threshold days for Alta (USC00130173), Iowa, United States, with 67 years of record.

Key Facts for Alta

  • Alta (USC00130173) is a weather station in Iowa, United States at 42.67 latitude and -95.30 longitude, 461 m (1,512 ft) above sea level.
  • The station reports from 1893 to 1959, 67 years of record.
  • 1,464 records set at Alta still stand.
  • Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Alta set a daily record low maximum temperature of 6.1 C (43.0 F) on 11 October 1959.

About the Station

  • Location: Iowa, United States, 42.67 latitude, -95.30 longitude.
  • Elevation: 461 m (1,512 ft).
  • Period of record: 1893 to 1959, 67 years.
  • Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

0 days at or beyond a record
Daily record high and record low at Alta, with 2026 drawn through them The band shows the record high and record low for each calendar day at Alta. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -40-200204060 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Alta. 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 Alta, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan13.9 C (57.0 F)-37.8 C (-36.0 F)n/an/a
Feb23.3 C (73.9 F)-36.1 C (-33.0 F)n/an/a
Mar29.4 C (84.9 F)-27.8 C (-18.0 F)n/an/a
Apr35.0 C (95.0 F)-15.0 C (5.0 F)n/an/a
May40.6 C (105.1 F)-6.1 C (21.0 F)n/an/a
Jun41.1 C (106.0 F)1.1 C (34.0 F)n/an/a
Jul43.3 C (109.9 F)5.6 C (42.1 F)n/an/a
Aug42.2 C (108.0 F)3.9 C (39.0 F)n/an/a
Sep39.4 C (102.9 F)-6.7 C (19.9 F)n/an/a
Oct33.3 C (91.9 F)-16.7 C (1.9 F)n/an/a
Nov25.0 C (77.0 F)-22.8 C (-9.0 F)n/an/a
Dec18.3 C (64.9 F)-32.8 C (-27.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Alta by the year they were set 1,464 records at Alta still stand. 1936 holds the most, with 59. 02040601893: 261894: 251895: 191896: 271897: 291898: 191899: 321900: 231901: 241902: 271903: 221904: 131905: 241906: 141907: 141908: 211909: 261910: 311911: 251912: 311913: 321914: 231915: 281916: 211917: 311918: 201919: 201920: 161921: 261922: 131923: 201924: 311925: 311926: 101927: 191928: 281929: 141930: 421931: 341932: 141933: 231934: 381935: 211936: 591937: 261938: 181939: 281940: 131941: 191942: 201943: 111944: 161945: 151946: 251947: 251948: 121949: 141950: 171951: 181952: 141953: 121954: 181955: 191956: 131957: 51958: 121959: 81893190019071914192119281935194219491956
1,464 records at Alta still stand. 1936 holds the most, with 59.
Standing records at Alta by the year they were set
Year setStanding records
189326
189425
189519
189627
189729
189819
189932
190023
190124
190227
190322
190413
190524
190614
190714
190821
190926
191031
191125
191231
191332
191423
191528
191621
191731
191820
191920
192016
192126
192213
192320
192431
192531
192610
192719
192828
192914
193042
193134
193214
193323
193438
193521
193659
193726
193818
193928
194013
194119
194220
194311
194416
194515
194625
194725
194812
194914
195017
195118
195214
195312
195418
195519
195613
19575
195812
19598

All-Time Record Progression

4 new records
When Alta set new all-time records 4 all-time records were set at Alta between 27 July 1930 and 25 December 1945. Each dot is a new record. Record high maximum temperatureRecord daily snowfall27 July 1930: Record high maximum temperature 41.7 C (107.1 F)3 August 1930: Record high maximum temperature 42.2 C (108.0 F)4 July 1936: Record high maximum temperature 43.3 C (109.9 F)25 December 1945: Record daily snowfall 27.9 cm (11.0 in)1930193519401945
4 all-time records were set at Alta between 27 July 1930 and 25 December 1945. Each dot is a new record.
When Alta set new all-time records
DateKindDetail
1930-07-27Record high maximum temperatureRecord high maximum temperature 41.7 C (107.1 F)
1930-08-03Record high maximum temperatureRecord high maximum temperature 42.2 C (108.0 F)
1936-07-04Record high maximum temperatureRecord high maximum temperature 43.3 C (109.9 F)
1945-12-25Record daily snowfallRecord daily snowfall 27.9 cm (11.0 in)

Wettest Day of Each Month

Sep: 154.9 mm (6.1 in)
Record daily precipitation for each month at Alta The wettest day on record for each calendar month at Alta. The most was 154.9 mm (6.1 in) on 18 September 1905. 050100150200 Jan: 31.0 mm (1.2 in), 5 January 1932 Jan Feb: 47.8 mm (1.9 in), 28 February 1951 Feb Mar: 68.6 mm (2.7 in), 31 March 1897 Mar Apr: 91.7 mm (3.6 in), 8 April 1896 Apr May: 106.7 mm (4.2 in), 27 May 1899 May Jun: 111.5 mm (4.4 in), 19 June 1954 Jun Jul: 103.6 mm (4.1 in), 8 July 1902 Jul Aug: 119.4 mm (4.7 in), 6 August 1898 Aug Sep: 154.9 mm (6.1 in), 18 September 1905 Sep Oct: 77.5 mm (3.1 in), 7 October 1914 Oct Nov: 50.8 mm (2.0 in), 8 November 1916 Nov Dec: 35.6 mm (1.4 in), 10 December 1911 Dec
The wettest day on record for each calendar month at Alta. The most was 154.9 mm (6.1 in) on 18 September 1905.
Record daily precipitation for each month at Alta
MonthRecord daily precipitation (mm)Date
Jan31.0 mm (1.2 in)5 January 1932
Feb47.8 mm (1.9 in)28 February 1951
Mar68.6 mm (2.7 in)31 March 1897
Apr91.7 mm (3.6 in)8 April 1896
May106.7 mm (4.2 in)27 May 1899
Jun111.5 mm (4.4 in)19 June 1954
Jul103.6 mm (4.1 in)8 July 1902
Aug119.4 mm (4.7 in)6 August 1898
Sep154.9 mm (6.1 in)18 September 1905
Oct77.5 mm (3.1 in)7 October 1914
Nov50.8 mm (2.0 in)8 November 1916
Dec35.6 mm (1.4 in)10 December 1911

Period of Record Coverage

1893 to 1959
Days with data per year at Alta 67 years of record at Alta, 1893 to 1959. 3 years have data for under 90 percent of days and are left out of rankings: 1943, 1944, 1959. 1893: 333 of 365 days1894: 351 of 365 days1895: 349 of 365 days1896: 353 of 366 days1897: 355 of 365 days1898: 356 of 365 days1899: 353 of 365 days1900: 354 of 365 days1901: 357 of 365 days1902: 363 of 365 days1903: 362 of 365 days1904: 365 of 366 days1905: 362 of 365 days1906: 360 of 365 days1907: 357 of 365 days1908: 358 of 366 days1909: 362 of 365 days1910: 350 of 365 days1911: 356 of 365 days1912: 358 of 366 days1913: 362 of 365 days1914: 357 of 365 days1915: 364 of 365 days1916: 361 of 366 days1917: 362 of 365 days1918: 364 of 365 days1919: 365 of 365 days1920: 365 of 366 days1921: 365 of 365 days1922: 365 of 365 days1923: 362 of 365 days1924: 364 of 366 days1925: 365 of 365 days1926: 364 of 365 days1927: 365 of 365 days1928: 366 of 366 days1929: 354 of 365 days1930: 364 of 365 days1931: 365 of 365 days1932: 365 of 366 days1933: 333 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: 364 of 365 days1942: 364 of 365 days1943: 208 of 365 days1944: 243 of 366 days1945: 363 of 365 days1946: 363 of 365 days1947: 364 of 365 days1948: 366 of 366 days1949: 365 of 365 days1950: 365 of 365 days1951: 365 of 365 days1952: 363 of 366 days1953: 364 of 365 days1954: 358 of 365 days1955: 365 of 365 days1956: 359 of 366 days1957: 364 of 365 days1958: 365 of 365 days1959: 296 of 365 days190019101920193019401950
67 years of record at Alta, 1893 to 1959. 3 years have data for under 90 percent of days and are left out of rankings: 1943, 1944, 1959.
Days with data per year at Alta
YearDays with dataShare of yearComplete
189333391%Yes
189435196%Yes
189534996%Yes
189635396%Yes
189735597%Yes
189835698%Yes
189935397%Yes
190035497%Yes
190135798%Yes
190236399%Yes
190336299%Yes
1904365100%Yes
190536299%Yes
190636099%Yes
190735798%Yes
190835898%Yes
190936299%Yes
191035096%Yes
191135698%Yes
191235898%Yes
191336299%Yes
191435798%Yes
1915364100%Yes
191636199%Yes
191736299%Yes
1918364100%Yes
1919365100%Yes
1920365100%Yes
1921365100%Yes
1922365100%Yes
192336299%Yes
192436499%Yes
1925365100%Yes
1926364100%Yes
1927365100%Yes
1928366100%Yes
192935497%Yes
1930364100%Yes
1931365100%Yes
1932365100%Yes
193333391%Yes
1934365100%Yes
1935365100%Yes
1936366100%Yes
1937365100%Yes
1938365100%Yes
1939365100%Yes
1940366100%Yes
1941364100%Yes
1942364100%Yes
194320857%No
194424366%No
194536399%Yes
194636399%Yes
1947364100%Yes
1948366100%Yes
1949365100%Yes
1950365100%Yes
1951365100%Yes
195236399%Yes
1953364100%Yes
195435898%Yes
1955365100%Yes
195635998%Yes
1957364100%Yes
1958365100%Yes
195929681%No

Latest Records

20
Latest records at Alta
DateStationRecordValueBeat old record byOld record stoodSignificance
11 October 1959Alta, USdaily low max6.1 C (43.0 F)0.6 C (1.1 F)12 years9 of 100 (Routine)
2 October 1959Alta, USdaily low max8.3 C (46.9 F)2.8 C (5.0 F)48 years24 of 100 (Routine)
1 October 1959Alta, USdaily low max8.3 C (46.9 F)2.8 C (5.0 F)52 years25 of 100 (Routine)
16 September 1959Alta, USdaily low max9.4 C (48.9 F)2.8 C (5.0 F)42 years22 of 100 (Routine)
21 August 1959Alta, USdaily high min (Tie)23.3 C (73.9 F)tie42 years4 of 100 (Routine)
8 August 1959Alta, USdaily low max (Tie)21.7 C (71.1 F)tie36 years4 of 100 (Routine)
2 August 1959Alta, USdaily rain49.0 mm (1.9 in)7.6 mm (0.30 in)8 years13 of 100 (Routine)
2 July 1959Alta, USdaily low min (Tie)9.4 C (48.9 F)tie54 years5 of 100 (Routine)
1 July 1959Alta, USdaily low min7.2 C (45.0 F)1.7 C (3.1 F)8 years13 of 100 (Routine)
30 June 1959Alta, USdaily low max12.8 C (55.0 F)5.5 C (9.9 F)36 years26 of 100 (Routine)
30 June 1959Alta, USdaily rain38.9 mm (1.5 in)11.0 mm (0.4 in)20 years19 of 100 (Routine)
29 June 1959Alta, USdaily low min (Tie)7.8 C (46.0 F)tie36 years4 of 100 (Routine)
28 June 1959Alta, USdaily rain43.2 mm (1.7 in)0.5 mm (0.02 in)34 years16 of 100 (Routine)
25 June 1959Alta, USdaily high min (Tie)23.3 C (73.9 F)tie4 years1 of 100 (Routine)
31 May 1959Alta, USdaily rain48.3 mm (1.9 in)6.9 mm (0.27 in)58 years28 of 100 (Routine)
15 May 1959Alta, USdaily low min (Tie)-0.6 C (30.9 F)tie52 years5 of 100 (Routine)
7 May 1959Alta, USdaily rain21.1 mm (0.8 in)3.3 mm (0.13 in)6 years10 of 100 (Routine)
6 May 1959Alta, USdaily rain26.4 mm (1.0 in)7.6 mm (0.30 in)26 years20 of 100 (Routine)
2 May 1959Alta, USdaily high min (Tie)17.8 C (64.0 F)tie20 years3 of 100 (Routine)
1 May 1959Alta, USdaily high max32.2 C (90.0 F)1.6 C (2.9 F)57 years25 of 100 (Routine)

Climate Trend

61 complete years, 1894 to 1958
Annual mean temperature at Alta as warming stripes, 1894 to 1958 One stripe for each of 61 complete years at Alta, 1894 to 1958. Blue stripes are years cooler than the station's own mean of 8.2 C (46.8 F); red stripes are warmer. The coolest year was 1917, at 5.7 C (42.3 F), and the warmest was 1931, at 11.1 C (52.0 F). The strongest colour marks a difference of 2.9 C (5.2 F). 1894: 8.8 C, +0.5 C from the station mean1895: 7.7 C, -0.5 C from the station mean1896: 8.0 C, -0.2 C from the station mean1897: 7.5 C, -0.7 C from the station mean1898: 7.9 C, -0.3 C from the station mean1899: 7.4 C, -0.8 C from the station mean1900: 8.5 C, +0.3 C from the station mean1901: 8.5 C, +0.3 C from the station mean1902: 7.4 C, -0.9 C from the station mean1903: 7.1 C, -1.1 C from the station mean1904: 6.8 C, -1.5 C from the station mean1905: 7.3 C, -0.9 C from the station mean1906: 7.9 C, -0.4 C from the station mean1907: 7.1 C, -1.1 C from the station mean1908: 8.1 C, -0.1 C from the station mean1909: 6.9 C, -1.4 C from the station mean1910: 8.2 C, 0.0 C from the station mean1911: 8.2 C, 0.0 C from the station mean1912: 6.7 C, -1.5 C from the station mean1913: 8.5 C, +0.3 C from the station mean1914: 8.1 C, -0.1 C from the station mean1915: 7.5 C, -0.7 C from the station mean1916: 6.9 C, -1.3 C from the station mean1917: 5.7 C, -2.5 C from the station mean1918: 8.2 C, 0.0 C from the station mean1919: 8.0 C, -0.2 C from the station mean1920: 8.0 C, -0.3 C from the station mean1921: 10.0 C, +1.8 C from the station mean1922: 8.8 C, +0.6 C from the station mean1923: 8.4 C, +0.2 C from the station mean1924: 6.7 C, -1.5 C from the station mean1925: 8.5 C, +0.3 C from the station mean1926: 8.3 C, +0.1 C from the station mean1927: 8.1 C, -0.1 C from the station mean1928: 8.9 C, +0.6 C from the station mean1930: 9.3 C, +1.1 C from the station mean1931: 11.1 C, +2.9 C from the station mean1932: 7.8 C, -0.4 C from the station mean1934: 9.8 C, +1.5 C from the station mean1935: 8.6 C, +0.3 C from the station mean1936: 8.1 C, -0.1 C from the station mean1937: 7.7 C, -0.5 C from the station mean1938: 9.6 C, +1.4 C from the station mean1939: 9.9 C, +1.6 C from the station mean1940: 8.0 C, -0.2 C from the station mean1941: 9.6 C, +1.4 C from the station mean1942: 8.6 C, +0.4 C from the station mean1945: 8.1 C, -0.1 C from the station mean1946: 9.8 C, +1.5 C from the station mean1947: 8.7 C, +0.5 C from the station mean1948: 8.8 C, +0.6 C from the station mean1949: 8.8 C, +0.6 C from the station mean1950: 6.9 C, -1.4 C from the station mean1951: 6.4 C, -1.8 C from the station mean1952: 8.4 C, +0.2 C from the station mean1953: 9.3 C, +1.0 C from the station mean1954: 9.3 C, +1.0 C from the station mean1955: 8.8 C, +0.5 C from the station mean1956: 8.9 C, +0.6 C from the station mean1957: 8.4 C, +0.1 C from the station mean1958: 8.4 C, +0.1 C from the station mean1894190019101920193019401950
One stripe for each of 61 complete years at Alta, 1894 to 1958. Blue stripes are years cooler than the station's own mean of 8.2 C (46.8 F); red stripes are warmer. The coolest year was 1917, at 5.7 C (42.3 F), and the warmest was 1931, at 11.1 C (52.0 F). The strongest colour marks a difference of 2.9 C (5.2 F).
Annual mean temperature at Alta as warming stripes, 1894 to 1958
YearAnnual mean temperatureDifference from the station mean
18948.8 C+0.53 C
18957.7 C-0.51 C
18968.0 C-0.24 C
18977.5 C-0.72 C
18987.9 C-0.31 C
18997.4 C-0.78 C
19008.5 C+0.26 C
19018.5 C+0.30 C
19027.4 C-0.87 C
19037.1 C-1.10 C
19046.8 C-1.45 C
19057.3 C-0.92 C
19067.9 C-0.35 C
19077.1 C-1.08 C
19088.1 C-0.10 C
19096.9 C-1.36 C
19108.2 C+0.02 C
19118.2 C-0.02 C
19126.7 C-1.53 C
19138.5 C+0.28 C
19148.1 C-0.12 C
19157.5 C-0.74 C
19166.9 C-1.32 C
19175.7 C-2.50 C
19188.2 C+0.02 C
19198.0 C-0.20 C
19208.0 C-0.26 C
192110.0 C+1.81 C
19228.8 C+0.61 C
19238.4 C+0.18 C
19246.7 C-1.52 C
19258.5 C+0.27 C
19268.3 C+0.09 C
19278.1 C-0.11 C
19288.9 C+0.65 C
19309.3 C+1.09 C
193111.1 C+2.88 C
19327.8 C-0.39 C
19349.8 C+1.55 C
19358.6 C+0.34 C
19368.1 C-0.11 C
19377.7 C-0.50 C
19389.6 C+1.41 C
19399.9 C+1.65 C
19408.0 C-0.24 C
19419.6 C+1.42 C
19428.6 C+0.42 C
19458.1 C-0.10 C
19469.8 C+1.53 C
19478.7 C+0.52 C
19488.8 C+0.61 C
19498.8 C+0.58 C
19506.9 C-1.35 C
19516.4 C-1.79 C
19528.4 C+0.18 C
19539.3 C+1.04 C
19549.3 C+1.03 C
19558.8 C+0.54 C
19568.9 C+0.64 C
19578.4 C+0.15 C
19588.4 C+0.13 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1894 to 1958. In Fahrenheit: 0.4 F (0.1 to 0.6) per decade. The slope is a straight line fitted to 61 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Alta
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.2 C (0.1 to 0.3) per decade0.4 F (0.1 to 0.6) per decade1894 to 195861Rise
Mean daily maximum0.17 C (0.02 to 0.31) per decade0.30 F (0.04 to 0.56) per decade1894 to 195861Rise
Mean daily minimum0.2 C (0.1 to 0.3) per decade0.4 F (0.2 to 0.6) per decade1894 to 195861Rise

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

1893 to 1959
Yearly extremes at Alta: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)43.3 C (109.9 F)193636.1 C (97.0 F)67
Coldest night (TNn)-37.8 C (-36.0 F)1912-28.3 C (-18.9 F)67
Wettest day (Rx1day)154.9 mm (6.1 in)190557.2 mm (2.3 in)67
Wettest five days (Rx5day)173.7 mm (6.8 in)191492.2 mm (3.6 in)67
Longest dry spell (CDD)53 days195226 days67

Hottest day (TXx)

Hottest day (TXx) at Alta by year The hottest day of the year at Alta, 1893 to 1959. The record is 43.3 C (109.9 F) in 1936, marked on the chart; the median year is 36.1 C (97.0 F). 30354045190019201940Record: 43.3 C (109.9 F) in 1936
The hottest day of the year at Alta, 1893 to 1959. The record is 43.3 C (109.9 F) in 1936, marked on the chart; the median year is 36.1 C (97.0 F).
Hottest day (TXx) at Alta by year
YearHottest day (TXx)
189335.0 C (95.0 F)
189441.1 C (106.0 F)
189536.7 C (98.1 F)
189635.0 C (95.0 F)
189735.6 C (96.1 F)
189835.6 C (96.1 F)
189936.7 C (98.1 F)
190034.4 C (93.9 F)
190140.6 C (105.1 F)
190232.2 C (90.0 F)
190331.7 C (89.1 F)
190433.3 C (91.9 F)
190535.6 C (96.1 F)
190635.0 C (95.0 F)
190733.9 C (93.0 F)
190834.4 C (93.9 F)
190934.4 C (93.9 F)
191035.6 C (96.1 F)
191138.9 C (102.0 F)
191235.6 C (96.1 F)
191338.3 C (100.9 F)
191436.1 C (97.0 F)
191531.7 C (89.1 F)
191635.6 C (96.1 F)
191736.7 C (98.1 F)
191837.2 C (99.0 F)
191935.0 C (95.0 F)
192033.3 C (91.9 F)
192136.1 C (97.0 F)
192235.6 C (96.1 F)
192333.9 C (93.0 F)
192433.3 C (91.9 F)
192539.4 C (102.9 F)
192638.3 C (100.9 F)
192735.0 C (95.0 F)
192836.7 C (98.1 F)
192936.7 C (98.1 F)
193042.2 C (108.0 F)
193138.9 C (102.0 F)
193236.7 C (98.1 F)
193341.1 C (106.0 F)
193440.6 C (105.1 F)
193540.0 C (104.0 F)
193643.3 C (109.9 F)
193740.0 C (104.0 F)
193836.7 C (98.1 F)
193938.9 C (102.0 F)
194040.6 C (105.1 F)
194139.4 C (102.9 F)
194236.7 C (98.1 F)
194336.1 C (97.0 F)
194435.0 C (95.0 F)
194535.6 C (96.1 F)
194637.8 C (100.0 F)
194740.0 C (104.0 F)
194837.2 C (99.0 F)
194935.0 C (95.0 F)
195032.8 C (91.0 F)
195132.8 C (91.0 F)
195235.6 C (96.1 F)
195335.6 C (96.1 F)
195437.2 C (99.0 F)
195540.6 C (105.1 F)
195637.2 C (99.0 F)
195736.1 C (97.0 F)
195833.9 C (93.0 F)
195933.9 C (93.0 F)

Coldest night (TNn)

Coldest night (TNn) at Alta by year The coldest night of the year at Alta, 1893 to 1959. The record is -37.8 C (-36.0 F) in 1912, marked on the chart; the median year is -28.3 C (-18.9 F). -40-35-30-25-20190019201940Record: -37.8 C (-36.0 F) in 1912
The coldest night of the year at Alta, 1893 to 1959. The record is -37.8 C (-36.0 F) in 1912, marked on the chart; the median year is -28.3 C (-18.9 F).
Coldest night (TNn) at Alta by year
YearColdest night (TNn)
1893-30.0 C (-22.0 F)
1894-33.9 C (-29.0 F)
1895-31.7 C (-25.1 F)
1896-26.1 C (-15.0 F)
1897-31.1 C (-24.0 F)
1898-28.3 C (-18.9 F)
1899-36.1 C (-33.0 F)
1900-26.7 C (-16.1 F)
1901-32.8 C (-27.0 F)
1902-28.9 C (-20.0 F)
1903-28.9 C (-20.0 F)
1904-32.2 C (-26.0 F)
1905-36.1 C (-33.0 F)
1906-26.7 C (-16.1 F)
1907-28.9 C (-20.0 F)
1908-26.1 C (-15.0 F)
1909-30.0 C (-22.0 F)
1910-27.8 C (-18.0 F)
1911-32.2 C (-26.0 F)
1912-37.8 C (-36.0 F)
1913-27.2 C (-17.0 F)
1914-28.9 C (-20.0 F)
1915-30.6 C (-23.1 F)
1916-32.2 C (-26.0 F)
1917-35.0 C (-31.0 F)
1918-36.1 C (-33.0 F)
1919-30.6 C (-23.1 F)
1920-25.0 C (-13.0 F)
1921-24.4 C (-11.9 F)
1922-26.7 C (-16.1 F)
1923-26.7 C (-16.1 F)
1924-35.0 C (-31.0 F)
1925-27.2 C (-17.0 F)
1926-26.1 C (-15.0 F)
1927-27.8 C (-18.0 F)
1928-25.6 C (-14.1 F)
1929-28.3 C (-18.9 F)
1930-30.6 C (-23.1 F)
1931-22.8 C (-9.0 F)
1932-28.9 C (-20.0 F)
1933-31.7 C (-25.1 F)
1934-25.0 C (-13.0 F)
1935-31.1 C (-24.0 F)
1936-32.2 C (-26.0 F)
1937-28.3 C (-18.9 F)
1938-25.0 C (-13.0 F)
1939-26.7 C (-16.1 F)
1940-31.7 C (-25.1 F)
1941-22.8 C (-9.0 F)
1942-32.2 C (-26.0 F)
1943-30.0 C (-22.0 F)
1944-20.6 C (-5.1 F)
1945-24.4 C (-11.9 F)
1946-25.6 C (-14.1 F)
1947-25.0 C (-13.0 F)
1948-26.7 C (-16.1 F)
1949-26.7 C (-16.1 F)
1950-29.4 C (-20.9 F)
1951-28.3 C (-18.9 F)
1952-27.2 C (-17.0 F)
1953-28.3 C (-18.9 F)
1954-29.4 C (-20.9 F)
1955-28.3 C (-18.9 F)
1956-28.3 C (-18.9 F)
1957-26.1 C (-15.0 F)
1958-27.2 C (-17.0 F)
1959-27.8 C (-18.0 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Alta by year The wettest day of the year at Alta, 1893 to 1959. The record is 154.9 mm (6.1 in) in 1905, marked on the chart; the median year is 57.2 mm (2.3 in). 050100150200190019201940Record: 154.9 mm (6.1 in) in 1905
The wettest day of the year at Alta, 1893 to 1959. The record is 154.9 mm (6.1 in) in 1905, marked on the chart; the median year is 57.2 mm (2.3 in).
Wettest day (Rx1day) at Alta by year
YearWettest day (Rx1day)
189376.2 mm (3.0 in)
189439.9 mm (1.6 in)
189591.4 mm (3.6 in)
189691.7 mm (3.6 in)
189768.6 mm (2.7 in)
1898119.4 mm (4.7 in)
1899106.7 mm (4.2 in)
1900108.0 mm (4.3 in)
190157.2 mm (2.3 in)
1902103.6 mm (4.1 in)
190358.4 mm (2.3 in)
190452.6 mm (2.1 in)
1905154.9 mm (6.1 in)
190645.7 mm (1.8 in)
190753.8 mm (2.1 in)
190878.0 mm (3.1 in)
190948.3 mm (1.9 in)
191027.4 mm (1.1 in)
191184.3 mm (3.3 in)
191290.7 mm (3.6 in)
191355.4 mm (2.2 in)
1914103.6 mm (4.1 in)
191557.2 mm (2.3 in)
191650.8 mm (2.0 in)
191752.3 mm (2.1 in)
191850.8 mm (2.0 in)
191978.7 mm (3.1 in)
192045.7 mm (1.8 in)
192176.2 mm (3.0 in)
192245.7 mm (1.8 in)
192352.1 mm (2.1 in)
192446.2 mm (1.8 in)
192551.6 mm (2.0 in)
192674.9 mm (2.9 in)
192744.5 mm (1.8 in)
192850.8 mm (2.0 in)
192938.1 mm (1.5 in)
193043.2 mm (1.7 in)
193155.9 mm (2.2 in)
193255.9 mm (2.2 in)
1933123.2 mm (4.9 in)
193463.0 mm (2.5 in)
193533.5 mm (1.3 in)
193645.7 mm (1.8 in)
193764.8 mm (2.6 in)
193895.0 mm (3.7 in)
193946.2 mm (1.8 in)
194068.1 mm (2.7 in)
194170.6 mm (2.8 in)
194250.8 mm (2.0 in)
194366.8 mm (2.6 in)
194481.0 mm (3.2 in)
194581.5 mm (3.2 in)
194658.2 mm (2.3 in)
194739.4 mm (1.6 in)
194879.8 mm (3.1 in)
194945.5 mm (1.8 in)
195043.2 mm (1.7 in)
195165.8 mm (2.6 in)
1952102.4 mm (4.0 in)
195367.8 mm (2.7 in)
1954111.5 mm (4.4 in)
195529.5 mm (1.2 in)
195635.8 mm (1.4 in)
195754.6 mm (2.1 in)
195850.8 mm (2.0 in)
195949.0 mm (1.9 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Alta by year The wettest five days of the year at Alta, 1893 to 1959. The record is 173.7 mm (6.8 in) in 1914, marked on the chart; the median year is 92.2 mm (3.6 in). 050100150200190019201940Record: 173.7 mm (6.8 in) in 1914
The wettest five days of the year at Alta, 1893 to 1959. The record is 173.7 mm (6.8 in) in 1914, marked on the chart; the median year is 92.2 mm (3.6 in).
Wettest five days (Rx5day) at Alta by year
YearWettest five days (Rx5day)
189388.1 mm (3.5 in)
189457.7 mm (2.3 in)
1895161.7 mm (6.4 in)
1896121.9 mm (4.8 in)
1897106.7 mm (4.2 in)
1898137.9 mm (5.4 in)
1899139.9 mm (5.5 in)
1900115.6 mm (4.6 in)
190180.0 mm (3.1 in)
1902169.1 mm (6.7 in)
190397.8 mm (3.9 in)
190477.5 mm (3.1 in)
1905168.3 mm (6.6 in)
190680.0 mm (3.1 in)
190787.5 mm (3.4 in)
1908123.7 mm (4.9 in)
190983.9 mm (3.3 in)
191043.1 mm (1.7 in)
191190.7 mm (3.6 in)
191296.1 mm (3.8 in)
191384.6 mm (3.3 in)
1914173.7 mm (6.8 in)
191574.8 mm (2.9 in)
191662.2 mm (2.4 in)
191775.7 mm (3.0 in)
1918110.7 mm (4.4 in)
1919151.9 mm (6.0 in)
192083.6 mm (3.3 in)
192197.8 mm (3.9 in)
192296.0 mm (3.8 in)
192393.5 mm (3.7 in)
192474.5 mm (2.9 in)
192587.9 mm (3.5 in)
1926147.1 mm (5.8 in)
192779.8 mm (3.1 in)
192868.1 mm (2.7 in)
192963.8 mm (2.5 in)
193070.6 mm (2.8 in)
1931100.9 mm (4.0 in)
193270.1 mm (2.8 in)
1933136.4 mm (5.4 in)
1934128.5 mm (5.1 in)
193547.1 mm (1.9 in)
193653.6 mm (2.1 in)
193797.0 mm (3.8 in)
1938140.0 mm (5.5 in)
193984.3 mm (3.3 in)
194090.7 mm (3.6 in)
1941161.5 mm (6.4 in)
194298.4 mm (3.9 in)
1943102.1 mm (4.0 in)
1944130.1 mm (5.1 in)
1945118.3 mm (4.7 in)
194662.6 mm (2.5 in)
194761.0 mm (2.4 in)
194881.1 mm (3.2 in)
194971.8 mm (2.8 in)
195076.0 mm (3.0 in)
195199.8 mm (3.9 in)
1952104.2 mm (4.1 in)
1953101.6 mm (4.0 in)
1954161.5 mm (6.4 in)
195544.5 mm (1.8 in)
195666.5 mm (2.6 in)
195783.1 mm (3.3 in)
195892.2 mm (3.6 in)
1959125.9 mm (5.0 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Alta by year The longest dry spell of the year at Alta, 1893 to 1959. The record is 53 days in 1952, marked on the chart; the median year is 26 days. 102030405060190019201940Record: 53 days in 1952
The longest dry spell of the year at Alta, 1893 to 1959. The record is 53 days in 1952, marked on the chart; the median year is 26 days.
Longest dry spell (CDD) at Alta by year
YearLongest dry spell (CDD)
189324 days
189424 days
189536 days
189624 days
189727 days
189827 days
189943 days
190028 days
190125 days
190219 days
190326 days
190435 days
190521 days
190626 days
190726 days
190825 days
190916 days
191046 days
191137 days
191225 days
191326 days
191447 days
191522 days
191641 days
191726 days
191822 days
191923 days
192021 days
192127 days
192219 days
192347 days
192432 days
192525 days
192621 days
192722 days
192819 days
192923 days
193030 days
193141 days
193221 days
193325 days
193442 days
193524 days
193627 days
193729 days
193828 days
193925 days
194020 days
194117 days
194237 days
194314 days
194414 days
194530 days
194628 days
194744 days
194837 days
194948 days
195026 days
195129 days
195253 days
195324 days
195434 days
195529 days
195623 days
195727 days
195837 days
195919 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

61 years with a frost

Across 61 years with a frost, the median last spring frost at Alta falls on 3 May and the median first autumn frost on 6 October, which leaves a median of 153 days between them.

In 1925 to 1958 the median growing season was 158 days. That is 9 days more than in 1894 to 1923.

Fitted over all years, the growing season changes by +2.7 days per decade at this station.

Frost dates and growing season at Alta
MeasureMedian, all yearsEarliest period (1894 to 1923)Recent period (1925 to 1958)Recent against earliestFitted trend
Last spring frost3 May4 May3 May1 day earlier-1.2 days per decade
First autumn frost6 October6 October6 Octoberno change+1.4 days per decade
Growing days153 days149 days158 days9 days more+2.7 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

61 years, 1893 to 1958

A day with at least 58.7 mm (2.3 in) of rain is expected about once in 2 years. A day with at least 162.8 mm (6.4 in) of rain is expected about once in 100 years.

Rainfall return levels at Alta: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years58.7 mm (2.3 in)
5 years81.0 mm (3.2 in)
10 years97.7 mm (3.8 in)
25 years121.5 mm (4.8 in)
50 years141.2 mm (5.6 in)
100 years162.8 mm (6.4 in)Longer than the 61 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, 61 years of values from 1893 to 1958.

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: 154.9 mm (6.1 in) in 1905; 123.2 mm (4.9 in) in 1933; 119.4 mm (4.7 in) in 1898.

Station Changes

No change in the annual mean temperature of this station was found against its neighbours.

Download the Data

  • Data for Alta standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Alta 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2025-12-31).