Built 2026-10-18 (18 October 2026)

Shemya USAF Base Weather Records (USW00045715)

Record envelope, standing records and threshold days for Shemya USAF Base (USW00045715), Alaska, United States, with 84 years of record.

Key Facts for Shemya USAF Base

  • Shemya USAF Base (USW00045715) is a weather station in Alaska, United States at 52.72 latitude and 174.10 longitude, 37 m (122 ft) above sea level.
  • The station reports from 1943 to 2026, 84 years of record.
  • 1,464 records set at Shemya USAF Base still stand.
  • Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Shemya USAF Base set a daily record high minimum temperature of 9.0 C (48.2 F) on 7 October 2026 (provisional).

Provisional Records

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

About the Station

  • Location: Alaska, United States, 52.72 latitude, 174.10 longitude.
  • Elevation: 37 m (122 ft).
  • Period of record: 1943 to 2026, 84 years.
  • Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

35 days at or beyond a record
Daily record high and record low at Shemya USAF Base, with 2026 drawn through them The band shows the record high and record low for each calendar day at Shemya USAF Base. The lines show the 2026 daily maximum and minimum. 35 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -20-1001020 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Shemya USAF Base. The lines show the 2026 daily maximum and minimum. 35 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Shemya USAF Base, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan6.7 C (44.1 F)-12.8 C (9.0 F)6.4 C (43.5 F)-10.2 C (13.6 F)
Feb6.7 C (44.1 F)-13.9 C (7.0 F)6.2 C (43.2 F)-5.9 C (21.4 F)
Mar6.5 C (43.7 F)-11.7 C (10.9 F)6.0 C (42.8 F)-6.4 C (20.5 F)
Apr8.3 C (46.9 F)-7.8 C (18.0 F)6.5 C (43.7 F)-2.0 C (28.4 F)
May9.6 C (49.3 F)-4.4 C (24.1 F)8.2 C (46.8 F)0.1 C (32.2 F)
Jun13.9 C (57.0 F)-1.7 C (28.9 F)10.0 C (50.0 F)3.0 C (37.4 F)
Jul17.8 C (64.0 F)1.2 C (34.2 F)12.0 C (53.6 F)5.8 C (42.4 F)
Aug17.2 C (63.0 F)3.3 C (37.9 F)15.5 C (59.9 F)8.0 C (46.4 F)
Sep15.0 C (59.0 F)0.6 C (33.1 F)13.4 C (56.1 F)-2.5 C (27.5 F)
Oct13.2 C (55.8 F)-3.3 C (26.1 F)11.7 C (53.1 F)4.6 C (40.3 F)
Nov8.9 C (48.0 F)-9.4 C (15.1 F)n/an/a
Dec8.9 C (48.0 F)-13.9 C (7.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Shemya USAF Base by the year they were set 1,464 records at Shemya USAF Base still stand. 2025 holds the most, with 144. 0501001501943: 201944: 421945: 221946: 351947: 751948: 251949: 151950: 571951: 171952: 191953: 271954: 171958: 51959: 141960: 271961: 191962: 221963: 271964: 511965: 121966: 221967: 241968: 261969: 201970: 231971: 431972: 361973: 91974: 141975: 411976: 291977: 411978: 41979: 151980: 301981: 731982: 361983: 121984: 141985: 191986: 301987: 111988: 101989: 131990: 391991: 391992: 81993: 221994: 121995: 52025: 1442026: 52194319491958196419701976198219881994
1,464 records at Shemya USAF Base still stand. 2025 holds the most, with 144.
Standing records at Shemya USAF Base by the year they were set
Year setStanding records
194320
194442
194522
194635
194775
194825
194915
195057
195117
195219
195327
195417
19585
195914
196027
196119
196222
196327
196451
196512
196622
196724
196826
196920
197023
197143
197236
19739
197414
197541
197629
197741
19784
197915
198030
198173
198236
198312
198414
198519
198630
198711
198810
198913
199039
199139
19928
199322
199412
19955
2025144
202652

All-Time Record Progression

2 new records
When Shemya USAF Base set new all-time records 2 all-time records were set at Shemya USAF Base between 13 August 1981 and 28 July 1989. Each dot is a new record. Record high minimum temperatureRecord high maximum temperature13 August 1981: Record high minimum temperature 12.2 C (54.0 F)28 July 1989: Record high maximum temperature 17.8 C (64.0 F)19851990
2 all-time records were set at Shemya USAF Base between 13 August 1981 and 28 July 1989. Each dot is a new record.
When Shemya USAF Base set new all-time records
DateKindDetail
1981-08-13Record high minimum temperatureRecord high minimum temperature 12.2 C (54.0 F)
1989-07-28Record high maximum temperatureRecord high maximum temperature 17.8 C (64.0 F)

Wettest Day of Each Month

Oct: 132.1 mm (5.2 in)
Record daily precipitation for each month at Shemya USAF Base The wettest day on record for each calendar month at Shemya USAF Base. The most was 132.1 mm (5.2 in) on 11 October 1962. 050100150 Jan: 31.2 mm (1.2 in), 2 January 1987 Jan Feb: 39.6 mm (1.6 in), 26 February 1954 Feb Mar: 36.6 mm (1.4 in), 30 March 1954 Mar Apr: 39.4 mm (1.6 in), 8 April 1950 Apr May: 35.3 mm (1.4 in), 15 May 1954 May Jun: 47.8 mm (1.9 in), 18 June 1993 Jun Jul: 48.0 mm (1.9 in), 23 July 1987 Jul Aug: 56.9 mm (2.2 in), 19 August 1963 Aug Sep: 52.8 mm (2.1 in), 12 September 1993 Sep Oct: 132.1 mm (5.2 in), 11 October 1962 Oct Nov: 62.5 mm (2.5 in), 23 November 1994 Nov Dec: 39.9 mm (1.6 in), 14 December 1987 Dec
The wettest day on record for each calendar month at Shemya USAF Base. The most was 132.1 mm (5.2 in) on 11 October 1962.
Record daily precipitation for each month at Shemya USAF Base
MonthRecord daily precipitation (mm)Date
Jan31.2 mm (1.2 in)2 January 1987
Feb39.6 mm (1.6 in)26 February 1954
Mar36.6 mm (1.4 in)30 March 1954
Apr39.4 mm (1.6 in)8 April 1950
May35.3 mm (1.4 in)15 May 1954
Jun47.8 mm (1.9 in)18 June 1993
Jul48.0 mm (1.9 in)23 July 1987
Aug56.9 mm (2.2 in)19 August 1963
Sep52.8 mm (2.1 in)12 September 1993
Oct132.1 mm (5.2 in)11 October 1962
Nov62.5 mm (2.5 in)23 November 1994
Dec39.9 mm (1.6 in)14 December 1987

Period of Record Coverage

1943 to 2026
Days with data per year at Shemya USAF Base 52 years of record at Shemya USAF Base, 1943 to 2026. 11 years have data for under 90 percent of days and are left out of rankings: 1943, 1954, 1958, 1973, 1974, 1977, 1978, 1992 and others. 1943: 184 of 365 days1944: 366 of 366 days1945: 363 of 365 days1946: 362 of 365 days1947: 360 of 365 days1948: 366 of 366 days1949: 365 of 365 days1950: 365 of 365 days1951: 363 of 365 days1952: 365 of 366 days1953: 365 of 365 days1954: 212 of 365 days1958: 120 of 365 days1959: 354 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: 116 of 365 days1974: 245 of 365 days1975: 365 of 365 days1976: 366 of 366 days1977: 304 of 365 days1978: 152 of 365 days1979: 365 of 365 days1980: 366 of 366 days1981: 364 of 365 days1982: 364 of 365 days1983: 362 of 365 days1984: 364 of 366 days1985: 363 of 365 days1986: 364 of 365 days1987: 364 of 365 days1988: 366 of 366 days1989: 334 of 365 days1990: 364 of 365 days1991: 364 of 365 days1992: 176 of 366 days1993: 303 of 365 days1994: 333 of 365 days1995: 89 of 365 days2025: 343 of 365 days2026: 258 of 365 days19501960197019801990
52 years of record at Shemya USAF Base, 1943 to 2026. 11 years have data for under 90 percent of days and are left out of rankings: 1943, 1954, 1958, 1973, 1974, 1977, 1978, 1992 and others.
Days with data per year at Shemya USAF Base
YearDays with dataShare of yearComplete
194318450%No
1944366100%Yes
194536399%Yes
194636299%Yes
194736099%Yes
1948366100%Yes
1949365100%Yes
1950365100%Yes
195136399%Yes
1952365100%Yes
1953365100%Yes
195421258%No
195812033%No
195935497%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
197311632%No
197424567%No
1975365100%Yes
1976366100%Yes
197730483%No
197815242%No
1979365100%Yes
1980366100%Yes
1981364100%Yes
1982364100%Yes
198336299%Yes
198436499%Yes
198536399%Yes
1986364100%Yes
1987364100%Yes
1988366100%Yes
198933492%Yes
1990364100%Yes
1991364100%Yes
199217648%No
199330383%No
199433391%Yes
19958924%No
202534394%Yes
202625871%No

Latest Records

20
Latest records at Shemya USAF Base
DateStationRecordValueBeat old record byOld record stoodSignificance
7 October 2026Shemya USAF Base, USdaily high min (Provisional)9.0 C (48.2 F)1.2 C (2.2 F)48 years27 of 100 (Routine)
7 October 2026Shemya USAF Base, USdaily high max (Provisional)11.0 C (51.8 F)0.4 C (0.7 F)40 years22 of 100 (Routine)
1 October 2026Shemya USAF Base, USdaily high min (Provisional)10.0 C (50.0 F)1.7 C (3.1 F)83 years39 of 100 (Notable)
30 September 2026Shemya USAF Base, USdaily high min (Provisional)9.0 C (48.2 F)0.7 C (1.3 F)52 years27 of 100 (Routine)
19 September 2026Shemya USAF Base, USdaily high min (Provisional)10.1 C (50.2 F)0.7 C (1.3 F)37 years23 of 100 (Routine)
18 September 2026Shemya USAF Base, USdaily high min (Tie, Provisional)10.0 C (50.0 F)tie44 years5 of 100 (Routine)
17 September 2026Shemya USAF Base, USmonthly low min (Provisional)-2.5 C (27.5 F)3.1 C (5.6 F)55 years51 of 100 (Notable)
16 September 2026Shemya USAF Base, USdaily high min (Provisional)10.5 C (50.9 F)0.2 C (0.4 F)0 years9 of 100 (Routine)
10 September 2026Shemya USAF Base, USdaily high min (Provisional)10.9 C (51.6 F)0.9 C (1.6 F)44 years26 of 100 (Routine)
9 September 2026Shemya USAF Base, USdaily high min (Provisional)11.0 C (51.8 F)0.4 C (0.7 F)48 years24 of 100 (Routine)
1 September 2026Shemya USAF Base, USmonthly high min (Provisional)11.8 C (53.2 F)0.1 C (0.2 F)48 years32 of 100 (Routine)
31 August 2026Shemya USAF Base, USdaily high max (Provisional)15.0 C (59.0 F)2.2 C (4.0 F)83 years46 of 100 (Notable)
31 August 2026Shemya USAF Base, USall-time high min (Provisional)12.6 C (54.7 F)0.4 C (0.7 F)45 years44 of 100 (Notable)
27 August 2026Shemya USAF Base, USdaily high min (Provisional)11.9 C (53.4 F)0.8 C (1.4 F)44 years27 of 100 (Routine)
26 August 2026Shemya USAF Base, USdaily high min (Provisional)12.0 C (53.6 F)1.4 C (2.5 F)44 years32 of 100 (Routine)
25 August 2026Shemya USAF Base, USdaily high min (Provisional)11.5 C (52.7 F)0.4 C (0.7 F)44 years24 of 100 (Routine)
22 August 2026Shemya USAF Base, USdaily high min (Provisional)12.0 C (53.6 F)0.4 C (0.7 F)0 years11 of 100 (Routine)
21 August 2026Shemya USAF Base, USdaily high max (Provisional)15.5 C (59.9 F)2.5 C (4.5 F)0 years24 of 100 (Routine)
21 August 2026Shemya USAF Base, USdaily high min (Provisional)11.8 C (53.2 F)0.1 C (0.2 F)44 years21 of 100 (Routine)
20 August 2026Shemya USAF Base, USdaily high min (Provisional)11.8 C (53.2 F)0.7 C (1.3 F)67 years33 of 100 (Routine)

Climate Trend

38 complete years, 1944 to 1991
Annual mean temperature at Shemya USAF Base as warming stripes, 1944 to 1991 One stripe for each of 38 complete years at Shemya USAF Base, 1944 to 1991. Blue stripes are years cooler than the station's own mean of 3.7 C (38.6 F); red stripes are warmer. The coolest year was 1964, at 3.0 C (37.4 F), and the warmest was 1991, at 4.6 C (40.3 F). The strongest colour marks a difference of 1.0 C (1.8 F). 1944: 3.8 C, +0.1 C from the station mean1945: 3.9 C, +0.2 C from the station mean1946: 3.6 C, -0.1 C from the station mean1947: 3.0 C, -0.7 C from the station mean1948: 4.0 C, +0.3 C from the station mean1949: 3.4 C, -0.3 C from the station mean1950: 4.2 C, +0.5 C from the station mean1951: 4.1 C, +0.4 C from the station mean1952: 3.6 C, 0.0 C from the station mean1953: 3.2 C, -0.5 C from the station mean1959: 3.9 C, +0.2 C from the station mean1960: 3.6 C, -0.1 C from the station mean1961: 3.4 C, -0.3 C from the station mean1962: 4.1 C, +0.4 C from the station mean1963: 4.1 C, +0.4 C from the station mean1964: 3.0 C, -0.7 C from the station mean1965: 3.7 C, +0.1 C from the station mean1966: 3.4 C, -0.3 C from the station mean1967: 3.6 C, -0.1 C from the station mean1968: 3.4 C, -0.3 C from the station mean1969: 3.6 C, -0.1 C from the station mean1970: 3.6 C, -0.1 C from the station mean1971: 3.0 C, -0.7 C from the station mean1972: 3.8 C, +0.1 C from the station mean1975: 3.2 C, -0.5 C from the station mean1976: 3.1 C, -0.5 C from the station mean1979: 3.6 C, -0.1 C from the station mean1980: 3.3 C, -0.4 C from the station mean1981: 4.0 C, +0.3 C from the station mean1982: 3.9 C, +0.3 C from the station mean1983: 3.9 C, +0.2 C from the station mean1984: 4.0 C, +0.3 C from the station mean1985: 3.7 C, 0.0 C from the station mean1986: 4.6 C, +0.9 C from the station mean1987: 3.5 C, -0.2 C from the station mean1988: 3.5 C, -0.2 C from the station mean1990: 4.6 C, +0.9 C from the station mean1991: 4.6 C, +0.9 C from the station mean1944195019551960196519701975198019851990
One stripe for each of 38 complete years at Shemya USAF Base, 1944 to 1991. Blue stripes are years cooler than the station's own mean of 3.7 C (38.6 F); red stripes are warmer. The coolest year was 1964, at 3.0 C (37.4 F), and the warmest was 1991, at 4.6 C (40.3 F). The strongest colour marks a difference of 1.0 C (1.8 F).
Annual mean temperature at Shemya USAF Base as warming stripes, 1944 to 1991
YearAnnual mean temperatureDifference from the station mean
19443.8 C+0.07 C
19453.9 C+0.24 C
19463.6 C-0.12 C
19473.0 C-0.67 C
19484.0 C+0.26 C
19493.4 C-0.28 C
19504.2 C+0.51 C
19514.1 C+0.40 C
19523.6 C-0.05 C
19533.2 C-0.49 C
19593.9 C+0.17 C
19603.6 C-0.11 C
19613.4 C-0.27 C
19624.1 C+0.38 C
19634.1 C+0.42 C
19643.0 C-0.71 C
19653.7 C+0.05 C
19663.4 C-0.33 C
19673.6 C-0.11 C
19683.4 C-0.29 C
19693.6 C-0.11 C
19703.6 C-0.14 C
19713.0 C-0.69 C
19723.8 C+0.07 C
19753.2 C-0.51 C
19763.1 C-0.55 C
19793.6 C-0.12 C
19803.3 C-0.44 C
19814.0 C+0.26 C
19823.9 C+0.25 C
19833.9 C+0.17 C
19844.0 C+0.30 C
19853.7 C-0.02 C
19864.6 C+0.94 C
19873.5 C-0.18 C
19883.5 C-0.18 C
19904.6 C+0.92 C
19914.6 C+0.94 C

The fitted trend in annual mean temperature here over 1944 to 1991 is 0.07 C (-0.03 to 0.16) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.3) per decade. The slope is a straight line fitted to 38 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Shemya USAF Base
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.07 C (-0.03 to 0.16) per decade0.1 F (-0.1 to 0.3) per decade1944 to 199138Not clearly different from zero
Mean daily maximum0.05 C (-0.05 to 0.15) per decade0.1 F (-0.1 to 0.3) per decade1944 to 199138Not clearly different from zero
Mean daily minimum0.09 C (-0.03 to 0.20) per decade0.2 F (-0.1 to 0.4) per decade1944 to 199138Not clearly different from zero

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

1943 to 2026
Yearly extremes at Shemya USAF Base: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)17.8 C (64.0 F)198914.4 C (57.9 F)52
Coldest night (TNn)-13.9 C (7.0 F)1971-7.8 C (18.0 F)52
Wettest day (Rx1day)132.1 mm (5.2 in)196233.1 mm (1.3 in)52
Wettest five days (Rx5day)173.0 mm (6.8 in)196256.6 mm (2.2 in)51
Longest dry spell (CDD)32 days194615 days52

Hottest day (TXx)

Hottest day (TXx) at Shemya USAF Base by year The hottest day of the year at Shemya USAF Base, 1943 to 2026. The record is 17.8 C (64.0 F) in 1989, marked on the chart; the median year is 14.4 C (57.9 F). 051015201960198020002020Record: 17.8 C (64.0 F) in 1989
The hottest day of the year at Shemya USAF Base, 1943 to 2026. The record is 17.8 C (64.0 F) in 1989, marked on the chart; the median year is 14.4 C (57.9 F).
Hottest day (TXx) at Shemya USAF Base by year
YearHottest day (TXx)
194315.6 C (60.1 F)
194415.6 C (60.1 F)
194517.2 C (63.0 F)
194617.2 C (63.0 F)
194711.1 C (52.0 F)
194814.4 C (57.9 F)
194912.8 C (55.0 F)
195013.9 C (57.0 F)
195114.4 C (57.9 F)
195214.4 C (57.9 F)
195313.9 C (57.0 F)
195414.4 C (57.9 F)
195812.2 C (54.0 F)
195915.6 C (60.1 F)
196014.4 C (57.9 F)
196113.9 C (57.0 F)
196212.2 C (54.0 F)
196312.8 C (55.0 F)
196415.0 C (59.0 F)
196512.8 C (55.0 F)
196613.3 C (55.9 F)
196715.0 C (59.0 F)
196815.6 C (60.1 F)
196915.6 C (60.1 F)
197015.0 C (59.0 F)
197111.1 C (52.0 F)
197215.6 C (60.1 F)
19734.4 C (39.9 F)
197412.2 C (54.0 F)
197514.4 C (57.9 F)
197611.7 C (53.1 F)
197716.1 C (61.0 F)
197812.8 C (55.0 F)
197915.0 C (59.0 F)
198013.3 C (55.9 F)
198116.1 C (61.0 F)
198213.3 C (55.9 F)
198315.0 C (59.0 F)
198414.4 C (57.9 F)
198513.9 C (57.0 F)
198616.1 C (61.0 F)
198711.7 C (53.1 F)
198814.4 C (57.9 F)
198917.8 C (64.0 F)
199015.0 C (59.0 F)
199112.8 C (55.0 F)
199210.6 C (51.1 F)
199315.6 C (60.1 F)
199412.8 C (55.0 F)
19954.4 C (39.9 F)
202516.0 C (60.8 F)
202615.5 C (59.9 F)

Coldest night (TNn)

Coldest night (TNn) at Shemya USAF Base by year The coldest night of the year at Shemya USAF Base, 1943 to 2026. The record is -13.9 C (7.0 F) in 1971, marked on the chart; the median year is -7.8 C (18.0 F). -15-12.5-10-7.5-5-2.51960198020002020Record: -13.9 C (7.0 F) in 1971
The coldest night of the year at Shemya USAF Base, 1943 to 2026. The record is -13.9 C (7.0 F) in 1971, marked on the chart; the median year is -7.8 C (18.0 F).
Coldest night (TNn) at Shemya USAF Base by year
YearColdest night (TNn)
1943-6.7 C (19.9 F)
1944-7.8 C (18.0 F)
1945-7.2 C (19.0 F)
1946-7.2 C (19.0 F)
1947-6.7 C (19.9 F)
1948-5.6 C (21.9 F)
1949-7.8 C (18.0 F)
1950-6.7 C (19.9 F)
1951-5.6 C (21.9 F)
1952-6.7 C (19.9 F)
1953-6.7 C (19.9 F)
1954-6.7 C (19.9 F)
1958-5.0 C (23.0 F)
1959-7.8 C (18.0 F)
1960-7.2 C (19.0 F)
1961-7.2 C (19.0 F)
1962-6.1 C (21.0 F)
1963-6.1 C (21.0 F)
1964-8.9 C (16.0 F)
1965-6.7 C (19.9 F)
1966-8.3 C (17.1 F)
1967-8.3 C (17.1 F)
1968-6.1 C (21.0 F)
1969-7.8 C (18.0 F)
1970-11.1 C (12.0 F)
1971-13.9 C (7.0 F)
1972-9.4 C (15.1 F)
1973-12.2 C (10.0 F)
1974-12.2 C (10.0 F)
1975-12.8 C (9.0 F)
1976-13.9 C (7.0 F)
1977-11.1 C (12.0 F)
1978-4.4 C (24.1 F)
1979-8.3 C (17.1 F)
1980-10.6 C (12.9 F)
1981-12.8 C (9.0 F)
1982-9.4 C (15.1 F)
1983-8.9 C (16.0 F)
1984-10.0 C (14.0 F)
1985-7.2 C (19.0 F)
1986-6.7 C (19.9 F)
1987-6.7 C (19.9 F)
1988-7.2 C (19.0 F)
1989-6.7 C (19.9 F)
1990-7.8 C (18.0 F)
1991-5.6 C (21.9 F)
1992-7.8 C (18.0 F)
1993-6.1 C (21.0 F)
1994-11.1 C (12.0 F)
1995-8.3 C (17.1 F)
2025-8.5 C (16.7 F)
2026-10.2 C (13.6 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Shemya USAF Base by year The wettest day of the year at Shemya USAF Base, 1943 to 2026. The record is 132.1 mm (5.2 in) in 1962, marked on the chart; the median year is 33.1 mm (1.3 in). 0501001501960198020002020Record: 132.1 mm (5.2 in) in 1962
The wettest day of the year at Shemya USAF Base, 1943 to 2026. The record is 132.1 mm (5.2 in) in 1962, marked on the chart; the median year is 33.1 mm (1.3 in).
Wettest day (Rx1day) at Shemya USAF Base by year
YearWettest day (Rx1day)
194321.3 mm (0.8 in)
194423.1 mm (0.9 in)
194523.4 mm (0.9 in)
194620.8 mm (0.8 in)
194727.2 mm (1.1 in)
194841.9 mm (1.6 in)
194929.0 mm (1.1 in)
195043.4 mm (1.7 in)
195113.7 mm (0.5 in)
195244.7 mm (1.8 in)
195340.4 mm (1.6 in)
195439.6 mm (1.6 in)
195822.9 mm (0.9 in)
195933.5 mm (1.3 in)
196034.3 mm (1.4 in)
196138.4 mm (1.5 in)
1962132.1 mm (5.2 in)
196356.9 mm (2.2 in)
196444.2 mm (1.7 in)
196529.2 mm (1.1 in)
196629.7 mm (1.2 in)
196750.5 mm (2.0 in)
196826.7 mm (1.1 in)
196937.1 mm (1.5 in)
197033.3 mm (1.3 in)
197144.5 mm (1.8 in)
197224.6 mm (1.0 in)
197318.5 mm (0.7 in)
197440.1 mm (1.6 in)
197537.6 mm (1.5 in)
197628.7 mm (1.1 in)
197731.0 mm (1.2 in)
197840.6 mm (1.6 in)
197932.8 mm (1.3 in)
198043.2 mm (1.7 in)
198140.6 mm (1.6 in)
198238.4 mm (1.5 in)
198322.1 mm (0.9 in)
198431.5 mm (1.2 in)
198530.7 mm (1.2 in)
198637.6 mm (1.5 in)
198752.6 mm (2.1 in)
198824.1 mm (0.9 in)
198928.7 mm (1.1 in)
199051.1 mm (2.0 in)
199132.5 mm (1.3 in)
199213.0 mm (0.5 in)
199352.8 mm (2.1 in)
199462.5 mm (2.5 in)
199519.3 mm (0.8 in)
202511.8 mm (0.5 in)
202610.0 mm (0.4 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Shemya USAF Base by year The wettest five days of the year at Shemya USAF Base, 1943 to 2026. The record is 173.0 mm (6.8 in) in 1962, marked on the chart; the median year is 56.6 mm (2.2 in). 0501001502001960198020002020Record: 173.0 mm (6.8 in) in 1962
The wettest five days of the year at Shemya USAF Base, 1943 to 2026. The record is 173.0 mm (6.8 in) in 1962, marked on the chart; the median year is 56.6 mm (2.2 in).
Wettest five days (Rx5day) at Shemya USAF Base by year
YearWettest five days (Rx5day)
194342.9 mm (1.7 in)
194433.8 mm (1.3 in)
194539.4 mm (1.6 in)
194626.6 mm (1.0 in)
194749.5 mm (1.9 in)
194864.3 mm (2.5 in)
194946.5 mm (1.8 in)
195049.3 mm (1.9 in)
195125.6 mm (1.0 in)
195280.7 mm (3.2 in)
195376.5 mm (3.0 in)
195447.5 mm (1.9 in)
195845.2 mm (1.8 in)
195962.2 mm (2.4 in)
196051.4 mm (2.0 in)
196152.3 mm (2.1 in)
1962173.0 mm (6.8 in)
1963100.8 mm (4.0 in)
196463.5 mm (2.5 in)
196551.1 mm (2.0 in)
196650.5 mm (2.0 in)
1967104.6 mm (4.1 in)
196838.1 mm (1.5 in)
196985.6 mm (3.4 in)
197056.6 mm (2.2 in)
197168.9 mm (2.7 in)
197242.6 mm (1.7 in)
197329.2 mm (1.1 in)
197491.6 mm (3.6 in)
1975122.0 mm (4.8 in)
197660.2 mm (2.4 in)
197740.6 mm (1.6 in)
197876.1 mm (3.0 in)
197954.1 mm (2.1 in)
198075.7 mm (3.0 in)
198162.4 mm (2.5 in)
198265.5 mm (2.6 in)
198344.0 mm (1.7 in)
198471.4 mm (2.8 in)
198561.9 mm (2.4 in)
198667.1 mm (2.6 in)
198774.4 mm (2.9 in)
198840.6 mm (1.6 in)
198942.4 mm (1.7 in)
1990116.1 mm (4.6 in)
199174.8 mm (2.9 in)
199229.2 mm (1.1 in)
199373.8 mm (2.9 in)
199483.0 mm (3.3 in)
199533.5 mm (1.3 in)
2025n/a
202610.0 mm (0.4 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Shemya USAF Base by year The longest dry spell of the year at Shemya USAF Base, 1943 to 2026. The record is 32 days in 1946, marked on the chart; the median year is 15 days. 0102030401960198020002020Record: 32 days in 1946
The longest dry spell of the year at Shemya USAF Base, 1943 to 2026. The record is 32 days in 1946, marked on the chart; the median year is 15 days.
Longest dry spell (CDD) at Shemya USAF Base by year
YearLongest dry spell (CDD)
19438 days
194417 days
194517 days
194632 days
194715 days
194815 days
194913 days
195011 days
195119 days
195214 days
195325 days
195417 days
195820 days
195922 days
196012 days
196116 days
196226 days
196318 days
196425 days
196514 days
196627 days
196718 days
196815 days
196912 days
197015 days
197122 days
197212 days
197319 days
197417 days
197512 days
197613 days
197720 days
197812 days
197911 days
198022 days
198122 days
198222 days
198322 days
198411 days
198515 days
198617 days
198711 days
198814 days
198919 days
199013 days
199113 days
19929 days
199316 days
199415 days
19956 days
20251 day
20267 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

38 years with a frost

Across 38 years with a frost, the median last spring frost at Shemya USAF Base falls on 6 May and the median first autumn frost on 29 October, which leaves a median of 177 days between them.

Fitted over all years, the growing season changes by +2.5 days per decade at this station.

Frost dates and growing season at Shemya USAF Base
MeasureMedian, all yearsEarliest periodRecent period (1952 to 1991)Recent against earliestFitted trend
Last spring frost6 Mayn/a4 Mayn/a-0.5 days per decade
First autumn frost29 Octobern/a27 Octobern/a+2.0 days per decade
Growing days177 daysn/a181 daysn/a+2.5 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

39 years, 1944 to 1994

A day with at least 34.0 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 101.8 mm (4.0 in) of rain is expected about once in 100 years.

Rainfall return levels at Shemya USAF Base: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years34.0 mm (1.3 in)
5 years47.1 mm (1.9 in)
10 years57.4 mm (2.3 in)
25 years72.9 mm (2.9 in)
50 years86.4 mm (3.4 in)Longer than the 39 years of record
100 years101.8 mm (4.0 in)Longer than the 39 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, 39 years of values from 1944 to 1994.

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: 132.1 mm (5.2 in) in 1962; 62.5 mm (2.5 in) in 1994; 56.9 mm (2.2 in) in 1963.

Download the Data

  • Data for Shemya USAF Base standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Shemya USAF Base 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-16).