Record envelope, standing records and threshold days for Tonsina (USC00509385), Alaska, United States, with 108 years of record.
Key Facts for Tonsina
Tonsina (USC00509385) is a weather station in Alaska, United States at 61.65 latitude and -145.17 longitude, 481 m (1,579 ft) above sea level.
The station reports from 1907 to 2014, 108 years of record.
1,464 records set at Tonsina still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Tonsina set a daily record snow depth of 40.6 cm (16.0 in) on 26 October 2014.
About the Station
Location: Alaska, United States, 61.65 latitude, -145.17 longitude.
Elevation: 481 m (1,579 ft).
Period of record: 1907 to 2014, 108 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Tonsina. 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 Tonsina, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
7.8 C (46.0 F)
-51.1 C (-60.0 F)
n/a
n/a
Feb
8.9 C (48.0 F)
-47.2 C (-53.0 F)
n/a
n/a
Mar
12.2 C (54.0 F)
-43.3 C (-45.9 F)
n/a
n/a
Apr
18.3 C (64.9 F)
-31.1 C (-24.0 F)
n/a
n/a
May
26.1 C (79.0 F)
-14.4 C (6.1 F)
n/a
n/a
Jun
32.2 C (90.0 F)
-7.8 C (18.0 F)
n/a
n/a
Jul
32.2 C (90.0 F)
-3.3 C (26.1 F)
n/a
n/a
Aug
31.1 C (88.0 F)
-8.3 C (17.1 F)
n/a
n/a
Sep
26.1 C (79.0 F)
-18.3 C (-0.9 F)
n/a
n/a
Oct
16.7 C (62.1 F)
-30.6 C (-23.1 F)
n/a
n/a
Nov
10.6 C (51.1 F)
-41.1 C (-42.0 F)
n/a
n/a
Dec
10.0 C (50.0 F)
-51.7 C (-61.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Tonsina still stand. 1915 holds the most, with 81.
Standing records at Tonsina by the year they were set
Year set
Standing records
1907
47
1914
31
1915
81
1917
20
1919
6
1963
14
1964
63
1965
63
1966
28
1967
34
1968
31
1969
43
1970
33
1971
31
1972
46
1973
13
1974
25
1975
56
1976
18
1977
20
1978
11
1979
33
1980
42
1981
31
1982
36
1983
15
1984
14
1985
38
1986
25
1987
13
1988
15
1989
39
1990
32
1991
14
1992
39
1993
22
1994
27
1995
27
1996
41
1997
16
1998
9
1999
21
2000
8
2001
7
2002
13
2005
1
2006
6
2007
5
2008
14
2009
32
2010
17
2011
14
2012
30
2013
40
2014
14
All-Time Record Progression
4 new records
4 all-time records were set at Tonsina between 17 March 1995 and 4 February 2012. Each dot is a new record.
When Tonsina set new all-time records
Date
Kind
Detail
1995-03-17
Record snow depth
Record snow depth 106.7 cm (42.0 in)
2012-01-06
Record snow depth
Record snow depth 127.0 cm (50.0 in)
2012-02-03
Record snow depth
Record snow depth 137.2 cm (54.0 in)
2012-02-04
Record snow depth
Record snow depth 139.7 cm (55.0 in)
Wettest Day of Each Month
Nov: 63.5 mm (2.5 in)
The wettest day on record for each calendar month at Tonsina. The most was 63.5 mm (2.5 in) on 1 November 1966.
Record daily precipitation for each month at Tonsina
Month
Record daily precipitation (mm)
Date
Jan
51.3 mm (2.0 in)
15 January 1981
Feb
45.7 mm (1.8 in)
19 February 1977
Mar
31.5 mm (1.2 in)
16 March 1995
Apr
33.3 mm (1.3 in)
26 April 1976
May
19.6 mm (0.8 in)
4 May 1977
Jun
25.4 mm (1.0 in)
12 June 1965
Jul
35.8 mm (1.4 in)
11 July 1974
Aug
28.2 mm (1.1 in)
22 August 1997
Sep
50.8 mm (2.0 in)
4 September 1914
Oct
58.4 mm (2.3 in)
10 October 1965
Nov
63.5 mm (2.5 in)
1 November 1966
Dec
32.5 mm (1.3 in)
24 December 1985
Period of Record Coverage
1907 to 2014
Complete yearUnder 90 percent of days
55 years of record at Tonsina, 1907 to 2014. 16 years have data for under 90 percent of days and are left out of rankings: 1907, 1914, 1915, 1917, 1919, 1963, 1966, 1967 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 35 complete years at Tonsina, 1964 to 2013. Blue stripes are years cooler than the station's own mean of -2.9 C (26.8 F); red stripes are warmer. The coolest year was 1996, at -5.3 C (22.5 F), and the warmest was 1981, at -0.9 C (30.3 F). The strongest colour marks a difference of 2.5 C (4.5 F).
Annual mean temperature at Tonsina as warming stripes, 1964 to 2013
Year
Annual mean temperature
Difference from the station mean
1964
-3.1 C
-0.26 C
1965
-3.4 C
-0.53 C
1968
-3.0 C
-0.14 C
1969
-2.6 C
+0.29 C
1970
-2.7 C
+0.16 C
1971
-4.1 C
-1.24 C
1972
-5.2 C
-2.36 C
1974
-4.0 C
-1.08 C
1977
-1.7 C
+1.20 C
1978
-1.9 C
+1.01 C
1979
-2.3 C
+0.62 C
1980
-3.0 C
-0.08 C
1981
-0.9 C
+1.95 C
1982
-4.5 C
-1.59 C
1983
-3.0 C
-0.16 C
1984
-2.4 C
+0.49 C
1985
-3.1 C
-0.21 C
1986
-2.3 C
+0.59 C
1987
-1.1 C
+1.80 C
1988
-2.5 C
+0.38 C
1989
-2.9 C
-0.03 C
1990
-3.0 C
-0.13 C
1991
-2.5 C
+0.39 C
1992
-3.3 C
-0.38 C
1993
-1.1 C
+1.79 C
1994
-2.7 C
+0.21 C
1996
-5.3 C
-2.42 C
1997
-2.3 C
+0.54 C
1998
-3.0 C
-0.15 C
1999
-3.7 C
-0.83 C
2009
-2.5 C
+0.35 C
2010
-2.7 C
+0.21 C
2011
-2.8 C
+0.10 C
2012
-4.6 C
-1.76 C
2013
-1.7 C
+1.19 C
The fitted trend in annual mean temperature here over 1964 to 2013 is 0.1 C (-0.2 to 0.3) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.4 to 0.6) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Tonsina
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (-0.2 to 0.3) per decade
0.1 F (-0.4 to 0.6) per decade
1964 to 2013
35
Not clearly different from zero
Mean daily maximum
-0.2 C (-0.4 to 0.1) per decade
-0.3 F (-0.7 to 0.1) per decade
1964 to 2013
35
Not clearly different from zero
Mean daily minimum
0.3 C (-0.1 to 0.6) per decade
0.5 F (-0.1 to 1.1) per decade
1964 to 2013
35
Not 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
1907 to 2014
Yearly extremes at Tonsina: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
32.2 C (90.0 F)
1915
28.3 C (82.9 F)
55
Coldest night (TNn)
-51.7 C (-61.1 F)
1964
-41.1 C (-42.0 F)
55
Wettest day (Rx1day)
63.5 mm (2.5 in)
1966
25.3 mm (1.0 in)
54
Wettest five days (Rx5day)
101.6 mm (4.0 in)
1914
37.0 mm (1.5 in)
52
Longest dry spell (CDD)
84 days
1974
33 days
53
Hottest day (TXx)
The hottest day of the year at Tonsina, 1907 to 2014. The record is 32.2 C (90.0 F) in 1915, marked on the chart; the median year is 28.3 C (82.9 F).
Hottest day (TXx) at Tonsina by year
Year
Hottest day (TXx)
1907
30.6 C (87.1 F)
1914
21.1 C (70.0 F)
1915
32.2 C (90.0 F)
1917
26.7 C (80.1 F)
1919
7.8 C (46.0 F)
1963
28.3 C (82.9 F)
1964
25.6 C (78.1 F)
1965
26.7 C (80.1 F)
1966
30.6 C (87.1 F)
1967
26.7 C (80.1 F)
1968
29.4 C (84.9 F)
1969
32.2 C (90.0 F)
1970
27.8 C (82.0 F)
1971
30.6 C (87.1 F)
1972
30.0 C (86.0 F)
1973
26.7 C (80.1 F)
1974
26.7 C (80.1 F)
1975
30.0 C (86.0 F)
1976
31.1 C (88.0 F)
1977
28.3 C (82.9 F)
1978
30.0 C (86.0 F)
1979
28.9 C (84.0 F)
1980
29.4 C (84.9 F)
1981
25.6 C (78.1 F)
1982
28.9 C (84.0 F)
1983
28.3 C (82.9 F)
1984
27.2 C (81.0 F)
1985
27.2 C (81.0 F)
1986
28.3 C (82.9 F)
1987
28.3 C (82.9 F)
1988
26.7 C (80.1 F)
1989
30.0 C (86.0 F)
1990
30.6 C (87.1 F)
1991
31.1 C (88.0 F)
1992
30.0 C (86.0 F)
1993
30.6 C (87.1 F)
1994
30.6 C (87.1 F)
1995
29.4 C (84.9 F)
1996
27.8 C (82.0 F)
1997
28.9 C (84.0 F)
1998
28.3 C (82.9 F)
1999
28.9 C (84.0 F)
2000
25.6 C (78.1 F)
2001
19.4 C (66.9 F)
2002
27.8 C (82.0 F)
2005
11.7 C (53.1 F)
2006
26.1 C (79.0 F)
2007
7.8 C (46.0 F)
2008
26.1 C (79.0 F)
2009
31.1 C (88.0 F)
2010
27.8 C (82.0 F)
2011
26.1 C (79.0 F)
2012
27.2 C (81.0 F)
2013
32.2 C (90.0 F)
2014
26.1 C (79.0 F)
Coldest night (TNn)
The coldest night of the year at Tonsina, 1907 to 2014. The record is -51.7 C (-61.1 F) in 1964, marked on the chart; the median year is -41.1 C (-42.0 F).
Coldest night (TNn) at Tonsina by year
Year
Coldest night (TNn)
1907
-31.1 C (-24.0 F)
1914
-38.3 C (-36.9 F)
1915
-38.3 C (-36.9 F)
1917
-23.3 C (-9.9 F)
1919
-38.9 C (-38.0 F)
1963
-37.8 C (-36.0 F)
1964
-51.7 C (-61.1 F)
1965
-42.2 C (-44.0 F)
1966
-46.7 C (-52.1 F)
1967
-41.1 C (-42.0 F)
1968
-47.2 C (-53.0 F)
1969
-45.6 C (-50.1 F)
1970
-48.9 C (-56.0 F)
1971
-48.9 C (-56.0 F)
1972
-50.0 C (-58.0 F)
1973
-45.0 C (-49.0 F)
1974
-43.3 C (-45.9 F)
1975
-51.1 C (-60.0 F)
1976
-41.7 C (-43.1 F)
1977
-43.3 C (-45.9 F)
1978
-37.2 C (-35.0 F)
1979
-43.9 C (-47.0 F)
1980
-46.7 C (-52.1 F)
1981
-44.4 C (-47.9 F)
1982
-44.4 C (-47.9 F)
1983
-36.7 C (-34.1 F)
1984
-43.3 C (-45.9 F)
1985
-39.4 C (-38.9 F)
1986
-33.9 C (-29.0 F)
1987
-41.1 C (-42.0 F)
1988
-37.8 C (-36.0 F)
1989
-44.4 C (-47.9 F)
1990
-43.9 C (-47.0 F)
1991
-40.0 C (-40.0 F)
1992
-38.3 C (-36.9 F)
1993
-45.6 C (-50.1 F)
1994
-37.8 C (-36.0 F)
1995
-37.2 C (-35.0 F)
1996
-45.0 C (-49.0 F)
1997
-45.0 C (-49.0 F)
1998
-41.1 C (-42.0 F)
1999
-45.0 C (-49.0 F)
2000
-38.3 C (-36.9 F)
2001
-30.0 C (-22.0 F)
2002
-40.0 C (-40.0 F)
2005
-40.0 C (-40.0 F)
2006
-40.0 C (-40.0 F)
2007
-21.1 C (-6.0 F)
2008
-40.0 C (-40.0 F)
2009
-43.3 C (-45.9 F)
2010
-39.4 C (-38.9 F)
2011
-42.2 C (-44.0 F)
2012
-41.1 C (-42.0 F)
2013
-39.4 C (-38.9 F)
2014
-35.6 C (-32.1 F)
Wettest day (Rx1day)
The wettest day of the year at Tonsina, 1907 to 2014. The record is 63.5 mm (2.5 in) in 1966, marked on the chart; the median year is 25.3 mm (1.0 in).
Wettest day (Rx1day) at Tonsina by year
Year
Wettest day (Rx1day)
1907
12.7 mm (0.5 in)
1914
50.8 mm (2.0 in)
1915
n/a
1917
12.7 mm (0.5 in)
1919
0.0 mm (0.00 in)
1963
25.4 mm (1.0 in)
1964
32.3 mm (1.3 in)
1965
58.4 mm (2.3 in)
1966
63.5 mm (2.5 in)
1967
27.4 mm (1.1 in)
1968
40.6 mm (1.6 in)
1969
26.4 mm (1.0 in)
1970
12.7 mm (0.5 in)
1971
21.6 mm (0.9 in)
1972
17.8 mm (0.7 in)
1973
25.4 mm (1.0 in)
1974
35.8 mm (1.4 in)
1975
17.0 mm (0.7 in)
1976
40.1 mm (1.6 in)
1977
45.7 mm (1.8 in)
1978
22.1 mm (0.9 in)
1979
18.8 mm (0.7 in)
1980
25.1 mm (1.0 in)
1981
51.3 mm (2.0 in)
1982
13.2 mm (0.5 in)
1983
22.6 mm (0.9 in)
1984
19.8 mm (0.8 in)
1985
33.8 mm (1.3 in)
1986
17.5 mm (0.7 in)
1987
21.6 mm (0.9 in)
1988
25.4 mm (1.0 in)
1989
27.9 mm (1.1 in)
1990
26.4 mm (1.0 in)
1991
27.9 mm (1.1 in)
1992
26.4 mm (1.0 in)
1993
22.6 mm (0.9 in)
1994
15.2 mm (0.6 in)
1995
33.5 mm (1.3 in)
1996
15.5 mm (0.6 in)
1997
32.3 mm (1.3 in)
1998
23.4 mm (0.9 in)
1999
29.0 mm (1.1 in)
2000
22.6 mm (0.9 in)
2001
29.5 mm (1.2 in)
2002
14.2 mm (0.6 in)
2005
10.2 mm (0.4 in)
2006
16.0 mm (0.6 in)
2007
5.1 mm (0.20 in)
2008
24.6 mm (1.0 in)
2009
17.3 mm (0.7 in)
2010
29.0 mm (1.1 in)
2011
12.2 mm (0.5 in)
2012
26.7 mm (1.1 in)
2013
25.4 mm (1.0 in)
2014
34.3 mm (1.4 in)
Wettest five days (Rx5day)
The wettest five days of the year at Tonsina, 1907 to 2014. The record is 101.6 mm (4.0 in) in 1914, marked on the chart; the median year is 37.0 mm (1.5 in).
Wettest five days (Rx5day) at Tonsina by year
Year
Wettest five days (Rx5day)
1907
17.8 mm (0.7 in)
1914
101.6 mm (4.0 in)
1915
n/a
1917
n/a
1919
n/a
1963
32.2 mm (1.3 in)
1964
65.4 mm (2.6 in)
1965
58.4 mm (2.3 in)
1966
44.0 mm (1.7 in)
1967
32.3 mm (1.3 in)
1968
88.9 mm (3.5 in)
1969
28.7 mm (1.1 in)
1970
22.9 mm (0.9 in)
1971
30.3 mm (1.2 in)
1972
24.6 mm (1.0 in)
1973
34.3 mm (1.4 in)
1974
44.5 mm (1.8 in)
1975
36.9 mm (1.5 in)
1976
78.0 mm (3.1 in)
1977
45.7 mm (1.8 in)
1978
32.8 mm (1.3 in)
1979
37.1 mm (1.5 in)
1980
37.4 mm (1.5 in)
1981
58.9 mm (2.3 in)
1982
22.6 mm (0.9 in)
1983
40.5 mm (1.6 in)
1984
30.8 mm (1.2 in)
1985
45.4 mm (1.8 in)
1986
25.7 mm (1.0 in)
1987
37.3 mm (1.5 in)
1988
37.5 mm (1.5 in)
1989
28.2 mm (1.1 in)
1990
29.5 mm (1.2 in)
1991
40.8 mm (1.6 in)
1992
30.0 mm (1.2 in)
1993
35.6 mm (1.4 in)
1994
23.6 mm (0.9 in)
1995
56.6 mm (2.2 in)
1996
47.7 mm (1.9 in)
1997
40.9 mm (1.6 in)
1998
42.7 mm (1.7 in)
1999
65.2 mm (2.6 in)
2000
42.2 mm (1.7 in)
2001
37.6 mm (1.5 in)
2002
32.1 mm (1.3 in)
2005
10.2 mm (0.4 in)
2006
32.3 mm (1.3 in)
2007
10.5 mm (0.4 in)
2008
45.7 mm (1.8 in)
2009
26.4 mm (1.0 in)
2010
31.5 mm (1.2 in)
2011
26.2 mm (1.0 in)
2012
33.8 mm (1.3 in)
2013
42.1 mm (1.7 in)
2014
44.5 mm (1.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Tonsina, 1907 to 2014. The record is 84 days in 1974, marked on the chart; the median year is 33 days.
Longest dry spell (CDD) at Tonsina by year
Year
Longest dry spell (CDD)
1907
16 days
1914
24 days
1915
n/a
1917
n/a
1919
1 day
1963
18 days
1964
19 days
1965
18 days
1966
34 days
1967
30 days
1968
34 days
1969
42 days
1970
34 days
1971
36 days
1972
36 days
1973
44 days
1974
84 days
1975
32 days
1976
38 days
1977
33 days
1978
54 days
1979
54 days
1980
62 days
1981
41 days
1982
30 days
1983
33 days
1984
40 days
1985
33 days
1986
28 days
1987
30 days
1988
55 days
1989
54 days
1990
54 days
1991
42 days
1992
31 days
1993
44 days
1994
59 days
1995
24 days
1996
49 days
1997
33 days
1998
76 days
1999
20 days
2000
57 days
2001
17 days
2002
23 days
2005
25 days
2006
19 days
2007
23 days
2008
13 days
2009
31 days
2010
41 days
2011
38 days
2012
30 days
2013
28 days
2014
68 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
35 years with a frost
Across 35 years with a frost, the median last spring frost at Tonsina falls on 19 June and the median first autumn frost on 2 August, which leaves a median of 44 days between them.
Fitted over all years, the growing season changes by +4.6 days per decade at this station.
Frost dates and growing season at Tonsina
Measure
Median, all years
Earliest period
Recent period (1971 to 2013)
Recent against earliest
Fitted trend
Last spring frost
19 June
n/a
19 June
n/a
-0.4 days per decade
First autumn frost
2 August
n/a
8 August
n/a
+4.2 days per decade
Growing days
44 days
n/a
44 days
n/a
+4.6 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
37 years, 1964 to 2013
A day with at least 24.7 mm (1.0 in) of rain is expected about once in 2 years. A day with at least 53.2 mm (2.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Tonsina: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
24.7 mm (1.0 in)
5 years
32.8 mm (1.3 in)
10 years
38.0 mm (1.5 in)
25 years
44.3 mm (1.7 in)
50 years
48.8 mm (1.9 in)
Longer than the 37 years of record
100 years
53.2 mm (2.1 in)
Longer than the 37 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, 37 years of values from 1964 to 2013.
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: 51.3 mm (2.0 in) in 1981; 45.7 mm (1.8 in) in 1977; 40.6 mm (1.6 in) in 1968.
Download the Data
Data for Tonsina standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Tonsina 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.