Record envelope, standing records and threshold days for Koosharem (USC00424764), Utah, United States, with 117 years of record.
Key Facts for Koosharem
Koosharem (USC00424764) is a weather station in Utah, United States at 38.51 latitude and -111.88 longitude, 2,112 m (6,930 ft) above sea level.
The station reports from 1893 to 2009, 117 years of record.
1,464 records set at Koosharem still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Koosharem tied a daily record low maximum temperature of 6.1 C (43.0 F) on 15 April 2009.
About the Station
Location: Utah, United States, 38.51 latitude, -111.88 longitude.
Elevation: 2,112 m (6,930 ft).
Period of record: 1893 to 2009, 117 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 Koosharem. 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 Koosharem, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.8 C (64.0 F)
-33.3 C (-27.9 F)
n/a
n/a
Feb
20.6 C (69.1 F)
-31.1 C (-24.0 F)
n/a
n/a
Mar
25.0 C (77.0 F)
-25.0 C (-13.0 F)
n/a
n/a
Apr
26.1 C (79.0 F)
-17.8 C (0.0 F)
n/a
n/a
May
32.8 C (91.0 F)
-11.1 C (12.0 F)
n/a
n/a
Jun
35.6 C (96.1 F)
-7.8 C (18.0 F)
n/a
n/a
Jul
36.7 C (98.1 F)
-2.8 C (27.0 F)
n/a
n/a
Aug
36.7 C (98.1 F)
-3.3 C (26.1 F)
n/a
n/a
Sep
33.3 C (91.9 F)
-11.7 C (10.9 F)
n/a
n/a
Oct
32.2 C (90.0 F)
-21.1 C (-6.0 F)
n/a
n/a
Nov
25.6 C (78.1 F)
-27.2 C (-17.0 F)
n/a
n/a
Dec
17.2 C (63.0 F)
-35.6 C (-32.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Koosharem still stand. 1955 holds the most, with 45.
Standing records at Koosharem by the year they were set
Year set
Standing records
1893
16
1894
25
1895
33
1896
16
1897
17
1919
9
1920
6
1921
24
1922
33
1923
15
1924
3
1925
11
1926
14
1927
28
1928
14
1929
4
1952
10
1953
13
1954
24
1955
45
1956
36
1957
20
1958
16
1959
24
1960
24
1961
17
1962
44
1963
35
1964
24
1965
25
1966
22
1967
18
1968
16
1969
23
1970
14
1971
34
1972
28
1973
13
1974
23
1975
31
1976
17
1977
23
1978
16
1979
21
1980
26
1981
27
1982
18
1983
5
1984
13
1985
18
1986
26
1987
18
1988
14
1989
27
1990
25
1991
10
1992
16
1993
7
1994
13
1995
18
1996
22
1997
21
1998
12
1999
13
2000
35
2001
16
2002
19
2003
26
2004
22
2005
13
2006
21
2007
19
2008
15
2009
5
All-Time Record Progression
8 new records
8 all-time records were set at Koosharem between 25 July 1987 and 2 June 2005. Each dot is a new record.
When Koosharem set new all-time records
Date
Kind
Detail
1987-07-25
Record high minimum temperature
Record high minimum temperature 17.2 C (63.0 F)
1990-12-22
Record low minimum temperature
Record low minimum temperature -35.0 C (-31.0 F)
1990-12-23
Record low minimum temperature
Record low minimum temperature -35.6 C (-32.1 F)
1993-02-20
Record snow depth
Record snow depth 53.3 cm (21.0 in)
2002-07-02
Record high minimum temperature
Record high minimum temperature 18.3 C (64.9 F)
2002-07-03
Record high minimum temperature
Record high minimum temperature 19.4 C (66.9 F)
2002-07-15
Record high minimum temperature
Record high minimum temperature 20.6 C (69.1 F)
2005-06-02
Record daily precipitation
Record daily precipitation 40.6 mm (1.6 in)
Wettest Day of Each Month
Jun: 40.6 mm (1.6 in)
The wettest day on record for each calendar month at Koosharem. The most was 40.6 mm (1.6 in) on 2 June 2005.
Record daily precipitation for each month at Koosharem
Month
Record daily precipitation (mm)
Date
Jan
24.1 mm (0.9 in)
19 January 1929
Feb
22.9 mm (0.9 in)
26 February 1928
Mar
20.3 mm (0.8 in)
20 March 1897
Apr
25.4 mm (1.0 in)
12 April 2002
May
38.1 mm (1.5 in)
10 May 1922
Jun
40.6 mm (1.6 in)
2 June 2005
Jul
39.6 mm (1.6 in)
25 July 2007
Aug
37.1 mm (1.5 in)
15 August 1984
Sep
33.8 mm (1.3 in)
22 September 1967
Oct
35.6 mm (1.4 in)
21 October 2004
Nov
31.0 mm (1.2 in)
2 November 1978
Dec
18.8 mm (0.7 in)
6 December 1955
Period of Record Coverage
1893 to 2009
Complete yearUnder 90 percent of days
74 years of record at Koosharem, 1893 to 2009. 33 years have data for under 90 percent of days and are left out of rankings: 1893, 1896, 1897, 1919, 1920, 1923, 1924, 1925 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 35 complete years at Koosharem, 1894 to 2007. Blue stripes are years cooler than the station's own mean of 6.6 C (43.9 F); red stripes are warmer. The coolest year was 1975, at 5.1 C (41.2 F), and the warmest was 2000, at 8.0 C (46.3 F). The strongest colour marks a difference of 1.5 C (2.7 F).
Annual mean temperature at Koosharem as warming stripes, 1894 to 2007
Year
Annual mean temperature
Difference from the station mean
1894
5.3 C
-1.33 C
1895
5.4 C
-1.22 C
1926
6.7 C
+0.05 C
1927
6.2 C
-0.42 C
1928
5.7 C
-0.92 C
1953
6.6 C
+0.04 C
1954
7.8 C
+1.16 C
1957
6.5 C
-0.13 C
1958
7.3 C
+0.66 C
1959
7.2 C
+0.55 C
1960
6.9 C
+0.26 C
1962
7.0 C
+0.40 C
1965
6.3 C
-0.32 C
1966
6.7 C
+0.06 C
1967
6.4 C
-0.24 C
1969
6.4 C
-0.17 C
1970
6.3 C
-0.33 C
1971
5.9 C
-0.75 C
1972
6.6 C
-0.01 C
1974
6.2 C
-0.41 C
1975
5.1 C
-1.49 C
1976
6.6 C
+0.04 C
1977
7.1 C
+0.52 C
1978
6.5 C
-0.13 C
1979
5.9 C
-0.73 C
1980
7.0 C
+0.40 C
1981
7.9 C
+1.25 C
1983
6.7 C
+0.05 C
1985
5.9 C
-0.66 C
1990
6.9 C
+0.33 C
1992
7.1 C
+0.53 C
2000
8.0 C
+1.35 C
2001
7.2 C
+0.64 C
2006
7.0 C
+0.36 C
2007
7.3 C
+0.73 C
The annual mean temperature here has risen by 0.1 C (0.1 to 0.2) per decade over 1894 to 2007. In Fahrenheit: 0.2 F (0.1 to 0.4) 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 Koosharem
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (0.1 to 0.2) per decade
0.2 F (0.1 to 0.4) per decade
1894 to 2007
35
Rise
Mean daily maximum
0.2 C (0.1 to 0.3) per decade
0.3 F (0.1 to 0.5) per decade
1894 to 2007
35
Rise
Mean daily minimum
0.11 C (0.02 to 0.19) per decade
0.20 F (0.04 to 0.35) per decade
1894 to 2007
35
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
1893 to 2009
Yearly extremes at Koosharem: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.7 C (98.1 F)
1895
33.9 C (93.0 F)
74
Coldest night (TNn)
-35.6 C (-32.1 F)
1990
-26.1 C (-15.0 F)
74
Wettest day (Rx1day)
40.6 mm (1.6 in)
2005
20.3 mm (0.8 in)
78
Wettest five days (Rx5day)
81.1 mm (3.2 in)
1980
28.9 mm (1.1 in)
76
Longest dry spell (CDD)
103 days
1972
34 days
76
Hottest day (TXx)
The hottest day of the year at Koosharem, 1893 to 2009. The record is 36.7 C (98.1 F) in 1895, marked on the chart; the median year is 33.9 C (93.0 F).
Hottest day (TXx) at Koosharem by year
Year
Hottest day (TXx)
1893
33.9 C (93.0 F)
1894
32.2 C (90.0 F)
1895
36.7 C (98.1 F)
1896
32.2 C (90.0 F)
1897
28.3 C (82.9 F)
1909
n/a
1910
n/a
1919
20.0 C (68.0 F)
1920
33.3 C (91.9 F)
1921
33.9 C (93.0 F)
1922
33.9 C (93.0 F)
1923
23.9 C (75.0 F)
1924
15.6 C (60.1 F)
1925
32.8 C (91.0 F)
1926
32.2 C (90.0 F)
1927
33.3 C (91.9 F)
1928
31.1 C (88.0 F)
1929
10.0 C (50.0 F)
1948
n/a
1949
n/a
1950
n/a
1951
n/a
1952
32.8 C (91.0 F)
1953
35.6 C (96.1 F)
1954
35.0 C (95.0 F)
1955
35.6 C (96.1 F)
1956
33.3 C (91.9 F)
1957
32.8 C (91.0 F)
1958
35.0 C (95.0 F)
1959
34.4 C (93.9 F)
1960
36.1 C (97.0 F)
1961
34.4 C (93.9 F)
1962
33.9 C (93.0 F)
1963
33.9 C (93.0 F)
1964
33.9 C (93.0 F)
1965
31.1 C (88.0 F)
1966
32.8 C (91.0 F)
1967
33.3 C (91.9 F)
1968
32.8 C (91.0 F)
1969
32.8 C (91.0 F)
1970
33.9 C (93.0 F)
1971
34.4 C (93.9 F)
1972
34.4 C (93.9 F)
1973
35.0 C (95.0 F)
1974
33.9 C (93.0 F)
1975
32.2 C (90.0 F)
1976
36.1 C (97.0 F)
1977
35.0 C (95.0 F)
1978
35.0 C (95.0 F)
1979
35.0 C (95.0 F)
1980
34.4 C (93.9 F)
1981
35.0 C (95.0 F)
1982
32.8 C (91.0 F)
1983
32.8 C (91.0 F)
1984
32.8 C (91.0 F)
1985
35.0 C (95.0 F)
1986
33.3 C (91.9 F)
1987
35.6 C (96.1 F)
1988
34.4 C (93.9 F)
1989
36.7 C (98.1 F)
1990
33.9 C (93.0 F)
1991
33.3 C (91.9 F)
1992
32.8 C (91.0 F)
1993
32.2 C (90.0 F)
1994
35.0 C (95.0 F)
1995
35.6 C (96.1 F)
1996
35.0 C (95.0 F)
1997
33.3 C (91.9 F)
1998
33.9 C (93.0 F)
1999
32.8 C (91.0 F)
2000
35.6 C (96.1 F)
2001
33.3 C (91.9 F)
2002
35.6 C (96.1 F)
2003
35.6 C (96.1 F)
2004
31.7 C (89.1 F)
2005
30.6 C (87.1 F)
2006
35.0 C (95.0 F)
2007
34.4 C (93.9 F)
2008
30.6 C (87.1 F)
2009
20.0 C (68.0 F)
Coldest night (TNn)
The coldest night of the year at Koosharem, 1893 to 2009. The record is -35.6 C (-32.1 F) in 1990, marked on the chart; the median year is -26.1 C (-15.0 F).
Coldest night (TNn) at Koosharem by year
Year
Coldest night (TNn)
1893
-17.2 C (1.0 F)
1894
-27.2 C (-17.0 F)
1895
-27.8 C (-18.0 F)
1896
-19.4 C (-2.9 F)
1897
-26.1 C (-15.0 F)
1909
n/a
1910
n/a
1919
-31.7 C (-25.1 F)
1920
-22.8 C (-9.0 F)
1921
-20.6 C (-5.1 F)
1922
-30.6 C (-23.1 F)
1923
-26.1 C (-15.0 F)
1924
-28.9 C (-20.0 F)
1925
-15.0 C (5.0 F)
1926
-26.7 C (-16.1 F)
1927
-26.1 C (-15.0 F)
1928
-26.1 C (-15.0 F)
1929
-31.1 C (-24.0 F)
1948
n/a
1949
n/a
1950
n/a
1951
n/a
1952
-27.2 C (-17.0 F)
1953
-22.8 C (-9.0 F)
1954
-19.4 C (-2.9 F)
1955
-27.8 C (-18.0 F)
1956
-24.4 C (-11.9 F)
1957
-27.8 C (-18.0 F)
1958
-23.9 C (-11.0 F)
1959
-25.6 C (-14.1 F)
1960
-25.6 C (-14.1 F)
1961
-28.3 C (-18.9 F)
1962
-30.0 C (-22.0 F)
1963
-33.3 C (-27.9 F)
1964
-26.7 C (-16.1 F)
1965
-23.3 C (-9.9 F)
1966
-26.1 C (-15.0 F)
1967
-26.7 C (-16.1 F)
1968
-27.8 C (-18.0 F)
1969
-25.0 C (-13.0 F)
1970
-28.3 C (-18.9 F)
1971
-31.1 C (-24.0 F)
1972
-33.3 C (-27.9 F)
1973
-27.2 C (-17.0 F)
1974
-26.1 C (-15.0 F)
1975
-24.4 C (-11.9 F)
1976
-27.2 C (-17.0 F)
1977
-24.4 C (-11.9 F)
1978
-25.6 C (-14.1 F)
1979
-30.6 C (-23.1 F)
1980
-21.7 C (-7.1 F)
1981
-20.6 C (-5.1 F)
1982
-30.0 C (-22.0 F)
1983
-22.8 C (-9.0 F)
1984
-28.9 C (-20.0 F)
1985
-31.1 C (-24.0 F)
1986
-23.3 C (-9.9 F)
1987
-26.1 C (-15.0 F)
1988
-28.9 C (-20.0 F)
1989
-28.9 C (-20.0 F)
1990
-35.6 C (-32.1 F)
1991
-24.4 C (-11.9 F)
1992
-25.6 C (-14.1 F)
1993
-26.1 C (-15.0 F)
1994
-24.4 C (-11.9 F)
1995
-21.7 C (-7.1 F)
1996
-22.8 C (-9.0 F)
1997
-27.2 C (-17.0 F)
1998
-27.8 C (-18.0 F)
1999
-18.9 C (-2.0 F)
2000
-20.6 C (-5.1 F)
2001
-23.3 C (-9.9 F)
2002
-21.7 C (-7.1 F)
2003
-21.7 C (-7.1 F)
2004
-28.9 C (-20.0 F)
2005
-21.7 C (-7.1 F)
2006
-24.4 C (-11.9 F)
2007
-26.7 C (-16.1 F)
2008
-26.7 C (-16.1 F)
2009
-26.1 C (-15.0 F)
Wettest day (Rx1day)
The wettest day of the year at Koosharem, 1893 to 2009. The record is 40.6 mm (1.6 in) in 2005, marked on the chart; the median year is 20.3 mm (0.8 in).
Wettest day (Rx1day) at Koosharem by year
Year
Wettest day (Rx1day)
1893
20.1 mm (0.8 in)
1894
18.5 mm (0.7 in)
1895
17.8 mm (0.7 in)
1896
31.0 mm (1.2 in)
1897
20.3 mm (0.8 in)
1909
n/a
1910
n/a
1919
7.6 mm (0.30 in)
1920
12.2 mm (0.5 in)
1921
15.2 mm (0.6 in)
1922
38.1 mm (1.5 in)
1923
12.2 mm (0.5 in)
1924
12.7 mm (0.5 in)
1925
26.7 mm (1.1 in)
1926
12.7 mm (0.5 in)
1927
30.7 mm (1.2 in)
1928
25.4 mm (1.0 in)
1929
24.1 mm (0.9 in)
1948
25.4 mm (1.0 in)
1949
27.4 mm (1.1 in)
1950
16.0 mm (0.6 in)
1951
17.8 mm (0.7 in)
1952
22.9 mm (0.9 in)
1953
27.9 mm (1.1 in)
1954
20.8 mm (0.8 in)
1955
18.8 mm (0.7 in)
1956
15.2 mm (0.6 in)
1957
17.0 mm (0.7 in)
1958
21.6 mm (0.9 in)
1959
19.1 mm (0.8 in)
1960
19.3 mm (0.8 in)
1961
16.5 mm (0.6 in)
1962
10.9 mm (0.4 in)
1963
14.7 mm (0.6 in)
1964
14.7 mm (0.6 in)
1965
23.9 mm (0.9 in)
1966
17.5 mm (0.7 in)
1967
33.8 mm (1.3 in)
1968
18.0 mm (0.7 in)
1969
20.8 mm (0.8 in)
1970
22.1 mm (0.9 in)
1971
26.9 mm (1.1 in)
1972
27.7 mm (1.1 in)
1973
13.0 mm (0.5 in)
1974
24.6 mm (1.0 in)
1975
11.7 mm (0.5 in)
1976
19.3 mm (0.8 in)
1977
12.7 mm (0.5 in)
1978
31.0 mm (1.2 in)
1979
15.5 mm (0.6 in)
1980
24.9 mm (1.0 in)
1981
28.7 mm (1.1 in)
1982
29.0 mm (1.1 in)
1983
20.3 mm (0.8 in)
1984
37.1 mm (1.5 in)
1985
19.6 mm (0.8 in)
1986
15.5 mm (0.6 in)
1987
22.1 mm (0.9 in)
1988
21.1 mm (0.8 in)
1989
15.5 mm (0.6 in)
1990
13.0 mm (0.5 in)
1991
21.1 mm (0.8 in)
1992
26.7 mm (1.1 in)
1993
19.8 mm (0.8 in)
1994
15.2 mm (0.6 in)
1995
25.4 mm (1.0 in)
1996
16.5 mm (0.6 in)
1997
27.2 mm (1.1 in)
1998
20.3 mm (0.8 in)
1999
20.8 mm (0.8 in)
2000
27.4 mm (1.1 in)
2001
20.3 mm (0.8 in)
2002
25.4 mm (1.0 in)
2003
20.8 mm (0.8 in)
2004
35.6 mm (1.4 in)
2005
40.6 mm (1.6 in)
2006
30.7 mm (1.2 in)
2007
39.6 mm (1.6 in)
2008
14.0 mm (0.6 in)
2009
13.2 mm (0.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Koosharem, 1893 to 2009. The record is 81.1 mm (3.2 in) in 1980, marked on the chart; the median year is 28.9 mm (1.1 in).
Wettest five days (Rx5day) at Koosharem by year
Year
Wettest five days (Rx5day)
1893
21.4 mm (0.8 in)
1894
8.4 mm (0.33 in)
1895
23.4 mm (0.9 in)
1896
76.5 mm (3.0 in)
1897
20.3 mm (0.8 in)
1909
n/a
1910
n/a
1919
n/a
1920
n/a
1921
4.1 mm (0.16 in)
1922
27.9 mm (1.1 in)
1923
14.2 mm (0.6 in)
1924
16.7 mm (0.7 in)
1925
12.2 mm (0.5 in)
1926
13.4 mm (0.5 in)
1927
51.5 mm (2.0 in)
1928
24.0 mm (0.9 in)
1929
55.9 mm (2.2 in)
1948
26.7 mm (1.1 in)
1949
34.8 mm (1.4 in)
1950
26.7 mm (1.1 in)
1951
28.8 mm (1.1 in)
1952
23.8 mm (0.9 in)
1953
32.9 mm (1.3 in)
1954
35.8 mm (1.4 in)
1955
24.6 mm (1.0 in)
1956
30.5 mm (1.2 in)
1957
41.6 mm (1.6 in)
1958
23.9 mm (0.9 in)
1959
31.0 mm (1.2 in)
1960
37.6 mm (1.5 in)
1961
30.7 mm (1.2 in)
1962
16.2 mm (0.6 in)
1963
37.0 mm (1.5 in)
1964
29.4 mm (1.2 in)
1965
32.0 mm (1.3 in)
1966
24.4 mm (1.0 in)
1967
73.6 mm (2.9 in)
1968
25.6 mm (1.0 in)
1969
33.4 mm (1.3 in)
1970
31.3 mm (1.2 in)
1971
51.8 mm (2.0 in)
1972
40.4 mm (1.6 in)
1973
20.4 mm (0.8 in)
1974
28.4 mm (1.1 in)
1975
18.5 mm (0.7 in)
1976
20.1 mm (0.8 in)
1977
27.7 mm (1.1 in)
1978
38.1 mm (1.5 in)
1979
34.3 mm (1.4 in)
1980
81.1 mm (3.2 in)
1981
32.8 mm (1.3 in)
1982
61.2 mm (2.4 in)
1983
35.6 mm (1.4 in)
1984
44.9 mm (1.8 in)
1985
36.2 mm (1.4 in)
1986
18.5 mm (0.7 in)
1987
28.1 mm (1.1 in)
1988
28.1 mm (1.1 in)
1989
18.0 mm (0.7 in)
1990
30.1 mm (1.2 in)
1991
26.9 mm (1.1 in)
1992
40.2 mm (1.6 in)
1993
28.7 mm (1.1 in)
1994
34.0 mm (1.3 in)
1995
27.7 mm (1.1 in)
1996
21.3 mm (0.8 in)
1997
43.9 mm (1.7 in)
1998
27.4 mm (1.1 in)
1999
26.6 mm (1.0 in)
2000
42.2 mm (1.7 in)
2001
29.0 mm (1.1 in)
2002
47.9 mm (1.9 in)
2003
24.1 mm (0.9 in)
2004
63.5 mm (2.5 in)
2005
40.6 mm (1.6 in)
2006
52.0 mm (2.0 in)
2007
61.4 mm (2.4 in)
2008
20.1 mm (0.8 in)
2009
13.2 mm (0.5 in)
Longest dry spell (CDD)
The longest dry spell of the year at Koosharem, 1893 to 2009. The record is 103 days in 1972, marked on the chart; the median year is 34 days.
Longest dry spell (CDD) at Koosharem by year
Year
Longest dry spell (CDD)
1893
30 days
1894
34 days
1895
31 days
1896
37 days
1897
19 days
1909
n/a
1910
n/a
1919
n/a
1920
2 days
1921
8 days
1922
10 days
1923
33 days
1924
11 days
1925
13 days
1926
29 days
1927
34 days
1928
1 day
1929
n/a
1948
13 days
1949
64 days
1950
97 days
1951
34 days
1952
54 days
1953
44 days
1954
39 days
1955
44 days
1956
45 days
1957
33 days
1958
42 days
1959
37 days
1960
34 days
1961
32 days
1962
53 days
1963
26 days
1964
46 days
1965
31 days
1966
49 days
1967
33 days
1968
27 days
1969
34 days
1970
36 days
1971
36 days
1972
103 days
1973
43 days
1974
97 days
1975
27 days
1976
47 days
1977
49 days
1978
47 days
1979
48 days
1980
36 days
1981
29 days
1982
29 days
1983
23 days
1984
30 days
1985
42 days
1986
27 days
1987
22 days
1988
29 days
1989
46 days
1990
30 days
1991
32 days
1992
34 days
1993
35 days
1994
30 days
1995
31 days
1996
34 days
1997
38 days
1998
38 days
1999
45 days
2000
52 days
2001
40 days
2002
53 days
2003
32 days
2004
34 days
2005
28 days
2006
61 days
2007
35 days
2008
25 days
2009
30 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 Koosharem falls on 15 June and the median first autumn frost on 9 September, which leaves a median of 86 days between them.
Fitted over all years, the growing season changes by +0.4 days per decade at this station.
Frost dates and growing season at Koosharem
Measure
Median, all years
Earliest period
Recent period (1953 to 2007)
Recent against earliest
Fitted trend
Last spring frost
15 June
n/a
15 June
n/a
-0.7 days per decade
First autumn frost
9 September
n/a
10 September
n/a
-0.3 days per decade
Growing days
86 days
n/a
90 days
n/a
+0.4 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
56 years, 1949 to 2007
A day with at least 21.0 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 44.2 mm (1.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Koosharem: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
21.0 mm (0.8 in)
5 years
27.5 mm (1.1 in)
10 years
31.6 mm (1.2 in)
25 years
36.8 mm (1.4 in)
50 years
40.6 mm (1.6 in)
100 years
44.2 mm (1.7 in)
Longer than the 56 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, 56 years of values from 1949 to 2007.
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: 40.6 mm (1.6 in) in 2005; 39.6 mm (1.6 in) in 2007; 37.1 mm (1.5 in) in 1984.
Download the Data
Data for Koosharem standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Koosharem 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.