Record envelope, standing records and threshold days for Polson (USC00246635), Montana, United States, with 110 years of record.
Key Facts for Polson
Polson (USC00246635) is a weather station in Montana, United States at 47.67 latitude and -114.19 longitude, 917 m (3,010 ft) above sea level.
The station reports from 1906 to 2015, 110 years of record.
1,464 records set at Polson still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Polson set a daily record high maximum temperature of 21.1 C (70.0 F) on 28 March 2015.
About the Station
Location: Montana, United States, 47.67 latitude, -114.19 longitude.
Elevation: 917 m (3,010 ft).
Period of record: 1906 to 2015, 110 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 Polson. 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 Polson, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
14.4 C (57.9 F)
-34.4 C (-29.9 F)
n/a
n/a
Feb
18.9 C (66.0 F)
-32.8 C (-27.0 F)
n/a
n/a
Mar
23.3 C (73.9 F)
-23.3 C (-9.9 F)
n/a
n/a
Apr
28.9 C (84.0 F)
-18.3 C (-0.9 F)
n/a
n/a
May
32.8 C (91.0 F)
-8.3 C (17.1 F)
n/a
n/a
Jun
36.7 C (98.1 F)
-3.3 C (26.1 F)
n/a
n/a
Jul
40.0 C (104.0 F)
0.0 C (32.0 F)
n/a
n/a
Aug
38.3 C (100.9 F)
-0.6 C (30.9 F)
n/a
n/a
Sep
33.9 C (93.0 F)
-8.9 C (16.0 F)
n/a
n/a
Oct
28.3 C (82.9 F)
-17.2 C (1.0 F)
n/a
n/a
Nov
21.7 C (71.1 F)
-29.4 C (-20.9 F)
n/a
n/a
Dec
16.7 C (62.1 F)
-31.7 C (-25.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Polson still stand. 1936 holds the most, with 69.
Standing records at Polson by the year they were set
Year set
Standing records
1906
5
1907
10
1909
18
1910
21
1911
10
1912
7
1913
11
1914
11
1915
7
1916
29
1917
8
1918
16
1919
36
1920
11
1921
15
1922
17
1925
11
1926
28
1927
13
1928
10
1929
15
1930
28
1931
17
1932
24
1933
21
1934
18
1935
30
1936
69
1937
23
1938
12
1939
20
1940
14
1941
7
1942
6
1943
11
1944
10
1945
8
1946
7
1947
9
1948
8
1949
22
1950
22
1951
17
1952
10
1953
15
1954
11
1955
23
1956
14
1957
15
1958
9
1959
13
1960
23
1961
10
1962
10
1963
21
1964
10
1965
14
1972
16
1973
11
1974
15
1975
12
1976
10
1977
9
1978
6
1979
12
1980
18
1981
6
1982
11
1983
16
1984
6
1985
34
1986
17
1987
2
1988
9
1989
13
1990
23
1991
8
1992
13
1993
10
1994
19
1995
8
1996
10
1997
10
1998
6
1999
10
2000
7
2001
6
2002
14
2003
41
2004
10
2005
12
2006
8
2007
16
2008
21
2009
12
2010
9
2011
6
2012
21
2013
11
2014
17
2015
3
All-Time Record Progression
3 new records
3 all-time records were set at Polson between 31 January 1950 and 30 May 1985. Each dot is a new record.
When Polson set new all-time records
Date
Kind
Detail
1950-01-31
Record low minimum temperature
Record low minimum temperature -34.4 C (-29.9 F)
1964-06-08
Record daily precipitation
Record daily precipitation 63.5 mm (2.5 in)
1985-05-30
Record daily precipitation
Record daily precipitation 66.0 mm (2.6 in)
Wettest Day of Each Month
May: 66.0 mm (2.6 in)
The wettest day on record for each calendar month at Polson. The most was 66.0 mm (2.6 in) on 30 May 1985.
Record daily precipitation for each month at Polson
Month
Record daily precipitation (mm)
Date
Jan
24.9 mm (1.0 in)
7 January 1948
Feb
30.0 mm (1.2 in)
3 February 1915
Mar
26.4 mm (1.0 in)
29 March 1934
Apr
42.2 mm (1.7 in)
30 April 1951
May
66.0 mm (2.6 in)
30 May 1985
Jun
63.5 mm (2.5 in)
8 June 1964
Jul
44.7 mm (1.8 in)
3 July 1956
Aug
46.0 mm (1.8 in)
31 August 1986
Sep
35.1 mm (1.4 in)
9 September 1986
Oct
54.4 mm (2.1 in)
2 October 1946
Nov
28.4 mm (1.1 in)
2 November 2014
Dec
27.2 mm (1.1 in)
12 December 1929
Period of Record Coverage
1906 to 2015
Complete yearUnder 90 percent of days
102 years of record at Polson, 1906 to 2015. 19 years have data for under 90 percent of days and are left out of rankings: 1906, 1907, 1910, 1913, 1922, 1925, 1934, 1937 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 71 complete years at Polson, 1909 to 2014. Blue stripes are years cooler than the station's own mean of 7.6 C (45.7 F); red stripes are warmer. The coolest year was 1916, at 5.0 C (41.0 F), and the warmest was 1994, at 9.3 C (48.7 F). The strongest colour marks a difference of 2.6 C (4.7 F).
Annual mean temperature at Polson as warming stripes, 1909 to 2014
Year
Annual mean temperature
Difference from the station mean
1909
6.6 C
-0.99 C
1912
7.4 C
-0.25 C
1914
8.3 C
+0.67 C
1915
7.9 C
+0.27 C
1916
5.0 C
-2.59 C
1917
7.3 C
-0.30 C
1920
7.3 C
-0.26 C
1921
8.0 C
+0.35 C
1926
8.5 C
+0.86 C
1927
6.6 C
-1.03 C
1929
6.6 C
-0.99 C
1930
7.3 C
-0.27 C
1931
8.2 C
+0.55 C
1932
7.2 C
-0.41 C
1933
7.4 C
-0.20 C
1936
8.0 C
+0.37 C
1939
8.8 C
+1.22 C
1940
8.2 C
+0.56 C
1941
8.2 C
+0.63 C
1942
7.1 C
-0.51 C
1943
6.6 C
-1.00 C
1944
7.9 C
+0.32 C
1945
8.2 C
+0.60 C
1946
7.9 C
+0.34 C
1947
8.0 C
+0.43 C
1948
6.8 C
-0.85 C
1949
6.5 C
-1.11 C
1950
6.4 C
-1.20 C
1951
6.4 C
-1.24 C
1952
7.3 C
-0.32 C
1953
8.7 C
+1.09 C
1954
7.2 C
-0.40 C
1955
6.1 C
-1.53 C
1956
7.0 C
-0.61 C
1957
6.9 C
-0.71 C
1960
7.4 C
-0.25 C
1961
8.0 C
+0.36 C
1962
7.3 C
-0.35 C
1963
7.5 C
-0.07 C
1964
7.2 C
-0.43 C
1965
7.5 C
-0.09 C
1973
8.1 C
+0.45 C
1974
8.2 C
+0.61 C
1975
7.2 C
-0.43 C
1976
8.2 C
+0.59 C
1977
7.7 C
+0.08 C
1978
6.9 C
-0.66 C
1981
8.5 C
+0.90 C
1982
7.5 C
-0.09 C
1983
8.3 C
+0.71 C
1984
8.1 C
+0.50 C
1985
6.5 C
-1.06 C
1986
8.6 C
+0.97 C
1991
8.3 C
+0.68 C
1994
9.3 C
+1.67 C
1999
9.0 C
+1.43 C
2000
8.0 C
+0.40 C
2001
8.1 C
+0.45 C
2002
7.5 C
-0.13 C
2003
8.7 C
+1.13 C
2004
8.2 C
+0.63 C
2005
7.6 C
-0.04 C
2006
8.4 C
+0.76 C
2007
8.5 C
+0.90 C
2008
7.2 C
-0.45 C
2009
7.3 C
-0.26 C
2010
7.3 C
-0.29 C
2011
7.1 C
-0.51 C
2012
7.8 C
+0.18 C
2013
7.7 C
+0.12 C
2014
7.6 C
-0.04 C
The annual mean temperature here has risen by 0.07 C (0.02 to 0.13) per decade over 1909 to 2014. In Fahrenheit: 0.13 F (0.03 to 0.23) per decade. The slope is a straight line fitted to 71 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Polson
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.07 C (0.02 to 0.13) per decade
0.13 F (0.03 to 0.23) per decade
1909 to 2014
71
Rise
Mean daily maximum
0.08 C (0.01 to 0.14) per decade
0.14 F (0.03 to 0.24) per decade
1909 to 2014
71
Rise
Mean daily minimum
0.07 C (0.01 to 0.13) per decade
0.13 F (0.02 to 0.24) per decade
1909 to 2014
71
Rise
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
1906 to 2015
Yearly extremes at Polson: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
1919
35.0 C (95.0 F)
102
Coldest night (TNn)
-34.4 C (-29.9 F)
1950
-23.0 C (-9.5 F)
102
Wettest day (Rx1day)
66.0 mm (2.6 in)
1985
25.8 mm (1.0 in)
102
Wettest five days (Rx5day)
118.1 mm (4.6 in)
1980
40.6 mm (1.6 in)
102
Longest dry spell (CDD)
64 days
1931
28 days
102
Hottest day (TXx)
The hottest day of the year at Polson, 1906 to 2015. The record is 40.0 C (104.0 F) in 1919, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Polson by year
Year
Hottest day (TXx)
1906
35.6 C (96.1 F)
1907
32.2 C (90.0 F)
1909
33.3 C (91.9 F)
1910
36.7 C (98.1 F)
1911
31.7 C (89.1 F)
1912
32.8 C (91.0 F)
1913
36.1 C (97.0 F)
1914
36.7 C (98.1 F)
1915
33.9 C (93.0 F)
1916
31.7 C (89.1 F)
1917
35.6 C (96.1 F)
1918
34.4 C (93.9 F)
1919
40.0 C (104.0 F)
1920
36.1 C (97.0 F)
1921
37.8 C (100.0 F)
1922
36.1 C (97.0 F)
1925
34.4 C (93.9 F)
1926
37.8 C (100.0 F)
1927
33.9 C (93.0 F)
1928
35.6 C (96.1 F)
1929
36.1 C (97.0 F)
1930
36.7 C (98.1 F)
1931
37.8 C (100.0 F)
1932
35.0 C (95.0 F)
1933
36.7 C (98.1 F)
1934
40.0 C (104.0 F)
1935
33.3 C (91.9 F)
1936
38.9 C (102.0 F)
1937
35.0 C (95.0 F)
1938
37.8 C (100.0 F)
1939
37.2 C (99.0 F)
1940
33.9 C (93.0 F)
1941
35.6 C (96.1 F)
1942
35.0 C (95.0 F)
1943
34.4 C (93.9 F)
1944
34.4 C (93.9 F)
1945
35.6 C (96.1 F)
1946
36.1 C (97.0 F)
1947
32.2 C (90.0 F)
1948
31.1 C (88.0 F)
1949
35.6 C (96.1 F)
1950
32.2 C (90.0 F)
1951
33.3 C (91.9 F)
1952
32.8 C (91.0 F)
1953
35.6 C (96.1 F)
1954
33.9 C (93.0 F)
1955
33.3 C (91.9 F)
1956
32.8 C (91.0 F)
1957
31.1 C (88.0 F)
1958
35.0 C (95.0 F)
1959
35.0 C (95.0 F)
1960
40.0 C (104.0 F)
1961
38.3 C (100.9 F)
1962
33.3 C (91.9 F)
1963
36.7 C (98.1 F)
1964
33.3 C (91.9 F)
1965
32.2 C (90.0 F)
1966
11.7 C (53.1 F)
1972
35.0 C (95.0 F)
1973
35.0 C (95.0 F)
1974
33.9 C (93.0 F)
1975
36.7 C (98.1 F)
1976
33.3 C (91.9 F)
1977
34.4 C (93.9 F)
1978
35.6 C (96.1 F)
1979
33.9 C (93.0 F)
1980
33.3 C (91.9 F)
1981
35.0 C (95.0 F)
1982
33.9 C (93.0 F)
1983
37.2 C (99.0 F)
1984
35.6 C (96.1 F)
1985
36.7 C (98.1 F)
1986
35.6 C (96.1 F)
1987
33.9 C (93.0 F)
1988
35.6 C (96.1 F)
1989
35.6 C (96.1 F)
1990
35.6 C (96.1 F)
1991
34.4 C (93.9 F)
1992
36.1 C (97.0 F)
1993
32.2 C (90.0 F)
1994
35.0 C (95.0 F)
1995
33.9 C (93.0 F)
1996
36.1 C (97.0 F)
1997
31.7 C (89.1 F)
1998
33.9 C (93.0 F)
1999
36.1 C (97.0 F)
2000
35.0 C (95.0 F)
2001
34.4 C (93.9 F)
2002
34.4 C (93.9 F)
2003
38.9 C (102.0 F)
2004
34.4 C (93.9 F)
2005
34.4 C (93.9 F)
2006
37.2 C (99.0 F)
2007
38.9 C (102.0 F)
2008
36.7 C (98.1 F)
2009
33.9 C (93.0 F)
2010
35.0 C (95.0 F)
2011
33.9 C (93.0 F)
2012
32.8 C (91.0 F)
2013
35.0 C (95.0 F)
2014
33.9 C (93.0 F)
2015
21.1 C (70.0 F)
Coldest night (TNn)
The coldest night of the year at Polson, 1906 to 2015. The record is -34.4 C (-29.9 F) in 1950, marked on the chart; the median year is -23.0 C (-9.5 F).
Coldest night (TNn) at Polson by year
Year
Coldest night (TNn)
1906
-10.6 C (12.9 F)
1907
-24.4 C (-11.9 F)
1909
-27.2 C (-17.0 F)
1910
-25.0 C (-13.0 F)
1911
-20.0 C (-4.0 F)
1912
-21.7 C (-7.1 F)
1913
-20.6 C (-5.1 F)
1914
-26.7 C (-16.1 F)
1915
-19.4 C (-2.9 F)
1916
-27.8 C (-18.0 F)
1917
-17.8 C (0.0 F)
1918
-23.3 C (-9.9 F)
1919
-27.8 C (-18.0 F)
1920
-13.9 C (7.0 F)
1921
-19.4 C (-2.9 F)
1922
-22.2 C (-8.0 F)
1925
-7.8 C (18.0 F)
1926
-20.6 C (-5.1 F)
1927
-30.0 C (-22.0 F)
1928
-25.0 C (-13.0 F)
1929
-30.0 C (-22.0 F)
1930
-28.9 C (-20.0 F)
1931
-16.7 C (1.9 F)
1932
-25.6 C (-14.1 F)
1933
-31.1 C (-24.0 F)
1934
-14.4 C (6.1 F)
1935
-29.4 C (-20.9 F)
1936
-32.8 C (-27.0 F)
1937
-31.7 C (-25.1 F)
1938
-21.1 C (-6.0 F)
1939
-26.1 C (-15.0 F)
1940
-22.8 C (-9.0 F)
1941
-18.9 C (-2.0 F)
1942
-23.9 C (-11.0 F)
1943
-30.0 C (-22.0 F)
1944
-20.0 C (-4.0 F)
1945
-18.3 C (-0.9 F)
1946
-16.7 C (1.9 F)
1947
-15.6 C (3.9 F)
1948
-22.2 C (-8.0 F)
1949
-30.6 C (-23.1 F)
1950
-34.4 C (-29.9 F)
1951
-23.9 C (-11.0 F)
1952
-23.9 C (-11.0 F)
1953
-9.4 C (15.1 F)
1954
-22.8 C (-9.0 F)
1955
-27.8 C (-18.0 F)
1956
-27.8 C (-18.0 F)
1957
-32.2 C (-26.0 F)
1958
-12.8 C (9.0 F)
1959
-29.4 C (-20.9 F)
1960
-22.8 C (-9.0 F)
1961
-25.0 C (-13.0 F)
1962
-26.7 C (-16.1 F)
1963
-28.3 C (-18.9 F)
1964
-31.7 C (-25.1 F)
1965
-20.0 C (-4.0 F)
1966
-16.1 C (3.0 F)
1972
-26.7 C (-16.1 F)
1973
-23.3 C (-9.9 F)
1974
-26.1 C (-15.0 F)
1975
-18.9 C (-2.0 F)
1976
-16.1 C (3.0 F)
1977
-17.8 C (0.0 F)
1978
-26.7 C (-16.1 F)
1979
-28.9 C (-20.0 F)
1980
-13.9 C (7.0 F)
1981
-26.7 C (-16.1 F)
1982
-23.3 C (-9.9 F)
1983
-30.6 C (-23.1 F)
1984
-22.2 C (-8.0 F)
1985
-25.0 C (-13.0 F)
1986
-18.3 C (-0.9 F)
1987
-15.0 C (5.0 F)
1988
-13.3 C (8.1 F)
1989
-22.8 C (-9.0 F)
1990
-31.1 C (-24.0 F)
1991
-18.9 C (-2.0 F)
1992
-16.7 C (1.9 F)
1993
-22.2 C (-8.0 F)
1994
-23.9 C (-11.0 F)
1995
-15.0 C (5.0 F)
1996
-25.6 C (-14.1 F)
1997
-16.7 C (1.9 F)
1998
-24.4 C (-11.9 F)
1999
-12.2 C (10.0 F)
2000
-13.9 C (7.0 F)
2001
-13.9 C (7.0 F)
2002
-22.2 C (-8.0 F)
2003
-17.8 C (0.0 F)
2004
-25.6 C (-14.1 F)
2005
-21.1 C (-6.0 F)
2006
-25.0 C (-13.0 F)
2007
-17.8 C (0.0 F)
2008
-23.3 C (-9.9 F)
2009
-22.2 C (-8.0 F)
2010
-23.3 C (-9.9 F)
2011
-23.3 C (-9.9 F)
2012
-12.2 C (10.0 F)
2013
-25.0 C (-13.0 F)
2014
-30.0 C (-22.0 F)
2015
-20.0 C (-4.0 F)
Wettest day (Rx1day)
The wettest day of the year at Polson, 1906 to 2015. The record is 66.0 mm (2.6 in) in 1985, marked on the chart; the median year is 25.8 mm (1.0 in).
Wettest day (Rx1day) at Polson by year
Year
Wettest day (Rx1day)
1906
20.6 mm (0.8 in)
1907
18.3 mm (0.7 in)
1909
40.1 mm (1.6 in)
1910
24.9 mm (1.0 in)
1911
38.1 mm (1.5 in)
1912
24.1 mm (0.9 in)
1913
17.8 mm (0.7 in)
1914
23.4 mm (0.9 in)
1915
30.0 mm (1.2 in)
1916
61.7 mm (2.4 in)
1917
27.9 mm (1.1 in)
1918
15.7 mm (0.6 in)
1919
22.9 mm (0.9 in)
1920
18.3 mm (0.7 in)
1921
34.3 mm (1.4 in)
1922
26.7 mm (1.1 in)
1925
21.3 mm (0.8 in)
1926
22.9 mm (0.9 in)
1927
20.3 mm (0.8 in)
1928
16.5 mm (0.6 in)
1929
27.2 mm (1.1 in)
1930
34.3 mm (1.4 in)
1931
20.8 mm (0.8 in)
1932
26.9 mm (1.1 in)
1933
26.7 mm (1.1 in)
1934
34.3 mm (1.4 in)
1935
19.8 mm (0.8 in)
1936
20.3 mm (0.8 in)
1937
27.9 mm (1.1 in)
1938
16.0 mm (0.6 in)
1939
16.8 mm (0.7 in)
1940
26.7 mm (1.1 in)
1941
19.3 mm (0.8 in)
1942
23.6 mm (0.9 in)
1943
19.6 mm (0.8 in)
1944
27.4 mm (1.1 in)
1945
23.1 mm (0.9 in)
1946
54.4 mm (2.1 in)
1947
45.2 mm (1.8 in)
1948
46.5 mm (1.8 in)
1949
20.6 mm (0.8 in)
1950
23.6 mm (0.9 in)
1951
42.2 mm (1.7 in)
1952
20.1 mm (0.8 in)
1953
20.8 mm (0.8 in)
1954
25.4 mm (1.0 in)
1955
29.5 mm (1.2 in)
1956
44.7 mm (1.8 in)
1957
31.0 mm (1.2 in)
1958
45.7 mm (1.8 in)
1959
25.4 mm (1.0 in)
1960
36.8 mm (1.4 in)
1961
33.0 mm (1.3 in)
1962
23.6 mm (0.9 in)
1963
33.3 mm (1.3 in)
1964
63.5 mm (2.5 in)
1965
24.1 mm (0.9 in)
1966
7.6 mm (0.30 in)
1972
16.3 mm (0.6 in)
1973
34.0 mm (1.3 in)
1974
19.6 mm (0.8 in)
1975
22.4 mm (0.9 in)
1976
25.1 mm (1.0 in)
1977
27.2 mm (1.1 in)
1978
31.5 mm (1.2 in)
1979
18.8 mm (0.7 in)
1980
42.9 mm (1.7 in)
1981
21.6 mm (0.9 in)
1982
19.6 mm (0.8 in)
1983
25.4 mm (1.0 in)
1984
33.8 mm (1.3 in)
1985
66.0 mm (2.6 in)
1986
46.0 mm (1.8 in)
1987
25.7 mm (1.0 in)
1988
24.9 mm (1.0 in)
1989
19.6 mm (0.8 in)
1990
14.7 mm (0.6 in)
1991
46.0 mm (1.8 in)
1992
28.7 mm (1.1 in)
1993
24.1 mm (0.9 in)
1994
28.4 mm (1.1 in)
1995
25.7 mm (1.0 in)
1996
23.4 mm (0.9 in)
1997
36.8 mm (1.4 in)
1998
30.7 mm (1.2 in)
1999
29.0 mm (1.1 in)
2000
24.9 mm (1.0 in)
2001
35.6 mm (1.4 in)
2002
36.1 mm (1.4 in)
2003
19.8 mm (0.8 in)
2004
15.7 mm (0.6 in)
2005
46.5 mm (1.8 in)
2006
25.9 mm (1.0 in)
2007
28.7 mm (1.1 in)
2008
27.9 mm (1.1 in)
2009
22.6 mm (0.9 in)
2010
28.7 mm (1.1 in)
2011
30.5 mm (1.2 in)
2012
25.9 mm (1.0 in)
2013
25.9 mm (1.0 in)
2014
28.4 mm (1.1 in)
2015
10.7 mm (0.4 in)
Wettest five days (Rx5day)
The wettest five days of the year at Polson, 1906 to 2015. The record is 118.1 mm (4.6 in) in 1980, marked on the chart; the median year is 40.6 mm (1.6 in).
Wettest five days (Rx5day) at Polson by year
Year
Wettest five days (Rx5day)
1906
23.9 mm (0.9 in)
1907
31.0 mm (1.2 in)
1909
50.8 mm (2.0 in)
1910
38.2 mm (1.5 in)
1911
61.6 mm (2.4 in)
1912
42.7 mm (1.7 in)
1913
26.9 mm (1.1 in)
1914
68.6 mm (2.7 in)
1915
43.2 mm (1.7 in)
1916
78.4 mm (3.1 in)
1917
67.6 mm (2.7 in)
1918
31.0 mm (1.2 in)
1919
34.3 mm (1.4 in)
1920
43.1 mm (1.7 in)
1921
44.4 mm (1.7 in)
1922
26.7 mm (1.1 in)
1925
35.6 mm (1.4 in)
1926
35.8 mm (1.4 in)
1927
44.1 mm (1.7 in)
1928
26.7 mm (1.1 in)
1929
59.9 mm (2.4 in)
1930
37.1 mm (1.5 in)
1931
45.2 mm (1.8 in)
1932
46.0 mm (1.8 in)
1933
43.1 mm (1.7 in)
1934
54.9 mm (2.2 in)
1935
19.8 mm (0.8 in)
1936
31.4 mm (1.2 in)
1937
27.9 mm (1.1 in)
1938
27.1 mm (1.1 in)
1939
38.4 mm (1.5 in)
1940
31.3 mm (1.2 in)
1941
26.9 mm (1.1 in)
1942
43.7 mm (1.7 in)
1943
34.3 mm (1.4 in)
1944
44.7 mm (1.8 in)
1945
38.6 mm (1.5 in)
1946
54.4 mm (2.1 in)
1947
69.6 mm (2.7 in)
1948
66.9 mm (2.6 in)
1949
20.6 mm (0.8 in)
1950
39.8 mm (1.6 in)
1951
97.3 mm (3.8 in)
1952
32.2 mm (1.3 in)
1953
35.5 mm (1.4 in)
1954
32.0 mm (1.3 in)
1955
35.3 mm (1.4 in)
1956
51.1 mm (2.0 in)
1957
67.6 mm (2.7 in)
1958
48.2 mm (1.9 in)
1959
36.7 mm (1.4 in)
1960
49.5 mm (1.9 in)
1961
54.4 mm (2.1 in)
1962
45.0 mm (1.8 in)
1963
33.6 mm (1.3 in)
1964
84.3 mm (3.3 in)
1965
38.6 mm (1.5 in)
1966
15.3 mm (0.6 in)
1972
25.9 mm (1.0 in)
1973
40.8 mm (1.6 in)
1974
32.1 mm (1.3 in)
1975
32.1 mm (1.3 in)
1976
34.5 mm (1.4 in)
1977
39.7 mm (1.6 in)
1978
34.8 mm (1.4 in)
1979
41.4 mm (1.6 in)
1980
118.1 mm (4.6 in)
1981
38.1 mm (1.5 in)
1982
31.6 mm (1.2 in)
1983
40.9 mm (1.6 in)
1984
53.0 mm (2.1 in)
1985
87.8 mm (3.5 in)
1986
48.8 mm (1.9 in)
1987
41.5 mm (1.6 in)
1988
47.0 mm (1.9 in)
1989
59.0 mm (2.3 in)
1990
37.2 mm (1.5 in)
1991
80.5 mm (3.2 in)
1992
40.4 mm (1.6 in)
1993
32.8 mm (1.3 in)
1994
32.7 mm (1.3 in)
1995
38.9 mm (1.5 in)
1996
39.4 mm (1.6 in)
1997
51.9 mm (2.0 in)
1998
56.3 mm (2.2 in)
1999
30.5 mm (1.2 in)
2000
28.2 mm (1.1 in)
2001
46.2 mm (1.8 in)
2002
58.7 mm (2.3 in)
2003
27.5 mm (1.1 in)
2004
25.7 mm (1.0 in)
2005
73.0 mm (2.9 in)
2006
49.5 mm (1.9 in)
2007
37.4 mm (1.5 in)
2008
49.2 mm (1.9 in)
2009
34.8 mm (1.4 in)
2010
54.8 mm (2.2 in)
2011
50.6 mm (2.0 in)
2012
43.9 mm (1.7 in)
2013
42.7 mm (1.7 in)
2014
53.5 mm (2.1 in)
2015
23.4 mm (0.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at Polson, 1906 to 2015. The record is 64 days in 1931, marked on the chart; the median year is 28 days.
Longest dry spell (CDD) at Polson by year
Year
Longest dry spell (CDD)
1906
28 days
1907
45 days
1909
40 days
1910
50 days
1911
29 days
1912
37 days
1913
37 days
1914
42 days
1915
24 days
1916
21 days
1917
36 days
1918
34 days
1919
32 days
1920
34 days
1921
26 days
1922
43 days
1925
30 days
1926
47 days
1927
26 days
1928
40 days
1929
27 days
1930
21 days
1931
64 days
1932
26 days
1933
23 days
1934
62 days
1935
29 days
1936
33 days
1937
25 days
1938
27 days
1939
33 days
1940
32 days
1941
19 days
1942
23 days
1943
55 days
1944
29 days
1945
22 days
1946
23 days
1947
22 days
1948
29 days
1949
26 days
1950
22 days
1951
32 days
1952
29 days
1953
41 days
1954
25 days
1955
46 days
1956
21 days
1957
24 days
1958
19 days
1959
51 days
1960
30 days
1961
38 days
1962
22 days
1963
31 days
1964
39 days
1965
40 days
1966
13 days
1972
19 days
1973
27 days
1974
32 days
1975
15 days
1976
23 days
1977
22 days
1978
30 days
1979
35 days
1980
19 days
1981
26 days
1982
19 days
1983
22 days
1984
34 days
1985
46 days
1986
19 days
1987
27 days
1988
27 days
1989
14 days
1990
26 days
1991
30 days
1992
15 days
1993
22 days
1994
29 days
1995
18 days
1996
26 days
1997
20 days
1998
34 days
1999
35 days
2000
22 days
2001
53 days
2002
29 days
2003
45 days
2004
26 days
2005
50 days
2006
32 days
2007
43 days
2008
20 days
2009
34 days
2010
18 days
2011
22 days
2012
26 days
2013
21 days
2014
18 days
2015
6 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
71 years with a frost
Across 71 years with a frost, the median last spring frost at Polson falls on 13 May and the median first autumn frost on 28 September, which leaves a median of 138 days between them.
In 1973 to 2014 the median growing season was 139 days. That is 1 day more than in 1909 to 1952.
Fitted over all years, the growing season changes by -0.3 days per decade at this station.
Frost dates and growing season at Polson
Measure
Median, all years
Earliest period (1909 to 1952)
Recent period (1973 to 2014)
Recent against earliest
Fitted trend
Last spring frost
13 May
9 May
13 May
4 days later
+0.6 days per decade
First autumn frost
28 September
26 September
3 October
7 days later
+0.2 days per decade
Growing days
138 days
138 days
139 days
1 day more
-0.3 days per decade
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
86 years, 1909 to 2014
A day with at least 26.3 mm (1.0 in) of rain is expected about once in 2 years. A day with at least 69.6 mm (2.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Polson: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
26.3 mm (1.0 in)
5 years
35.0 mm (1.4 in)
10 years
41.8 mm (1.6 in)
25 years
51.7 mm (2.0 in)
50 years
60.2 mm (2.4 in)
100 years
69.6 mm (2.7 in)
Longer than the 86 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, 86 years of values from 1909 to 2014.
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: 66.0 mm (2.6 in) in 1985; 63.5 mm (2.5 in) in 1964; 61.7 mm (2.4 in) in 1916.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Polson, at 2000. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 2000 ran 0.3 C (0.6 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Polson, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
2000
-0.3
-0.6
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for Polson standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Polson 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.