Record envelope, standing records and threshold days for Prosser (USC00456768), Washington, United States, with 102 years of record.
Key Facts for Prosser
Prosser (USC00456768) is a weather station in Washington, United States at 46.20 latitude and -119.76 longitude, 253 m (830 ft) above sea level.
The station reports from 1925 to 2026, 102 years of record.
1,464 records set at Prosser still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Prosser set a daily record precipitation of 17.8 mm (0.7 in) on 29 May 2026.
About the Station
Location: Washington, United States, 46.20 latitude, -119.76 longitude.
Elevation: 253 m (830 ft).
Period of record: 1925 to 2026, 102 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 Prosser. 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 Prosser, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
20.6 C (69.1 F)
-28.9 C (-20.0 F)
15.6 C (60.1 F)
-7.8 C (18.0 F)
Feb
20.6 C (69.1 F)
-28.9 C (-20.0 F)
15.0 C (59.0 F)
-5.6 C (21.9 F)
Mar
27.2 C (81.0 F)
-14.4 C (6.1 F)
23.9 C (75.0 F)
-2.8 C (27.0 F)
Apr
32.8 C (91.0 F)
-10.0 C (14.0 F)
26.1 C (79.0 F)
0.6 C (33.1 F)
May
37.8 C (100.0 F)
-3.3 C (26.1 F)
32.8 C (91.0 F)
4.4 C (39.9 F)
Jun
45.6 C (114.1 F)
-1.1 C (30.0 F)
34.4 C (93.9 F)
6.7 C (44.1 F)
Jul
43.9 C (111.0 F)
-0.6 C (30.9 F)
38.9 C (102.0 F)
11.1 C (52.0 F)
Aug
41.1 C (106.0 F)
2.2 C (36.0 F)
37.8 C (100.0 F)
8.3 C (46.9 F)
Sep
38.3 C (100.9 F)
-6.1 C (21.0 F)
25.6 C (78.1 F)
5.6 C (42.1 F)
Oct
32.2 C (90.0 F)
-11.7 C (10.9 F)
n/a
n/a
Nov
24.4 C (75.9 F)
-21.7 C (-7.1 F)
n/a
n/a
Dec
21.1 C (70.0 F)
-23.9 C (-11.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Prosser still stand. 1950 holds the most, with 39.
Standing records at Prosser by the year they were set
Year set
Standing records
1925
1
1926
16
1927
10
1928
10
1929
26
1930
29
1931
6
1932
25
1933
28
1934
24
1935
21
1936
36
1937
19
1938
18
1939
17
1940
12
1941
14
1942
13
1943
17
1944
11
1945
19
1946
6
1947
13
1948
14
1949
23
1950
39
1951
14
1952
9
1953
15
1954
9
1955
30
1956
11
1957
11
1958
17
1959
9
1960
19
1961
17
1962
18
1963
6
1964
7
1965
18
1966
8
1967
15
1968
20
1969
13
1970
7
1971
23
1972
28
1973
14
1974
16
1975
13
1976
11
1977
12
1978
6
1979
8
1980
11
1981
9
1982
13
1983
11
1984
6
1985
37
1986
8
1987
18
1988
8
1989
9
1990
16
1991
3
1992
12
1993
11
1994
5
1996
11
1997
4
1998
11
1999
15
2000
10
2001
16
2002
19
2003
24
2004
11
2005
13
2006
21
2007
14
2008
5
2009
11
2010
6
2011
20
2012
11
2013
16
2014
14
2015
19
2016
12
2017
1
2018
12
2019
23
2020
7
2021
27
2022
23
2023
17
2024
9
2025
13
2026
1
All-Time Record Progression
6 new records
6 all-time records were set at Prosser between 6 June 1957 and 30 June 2021. Each dot is a new record.
When Prosser set new all-time records
Date
Kind
Detail
1957-06-06
Record daily precipitation
Record daily precipitation 43.2 mm (1.7 in)
1964-12-21
Record daily snowfall
Record daily snowfall 17.8 cm (7.0 in)
1980-01-09
Record daily snowfall
Record daily snowfall 24.1 cm (9.5 in)
2002-07-14
Record high maximum temperature
Record high maximum temperature 43.9 C (111.0 F)
2021-02-13
Record daily snowfall
Record daily snowfall 25.4 cm (10.0 in)
2021-06-30
Record high maximum temperature
Record high maximum temperature 45.6 C (114.1 F)
Wettest Day of Each Month
Jun: 43.2 mm (1.7 in)
The wettest day on record for each calendar month at Prosser. The most was 43.2 mm (1.7 in) on 6 June 1957.
Record daily precipitation for each month at Prosser
Month
Record daily precipitation (mm)
Date
Jan
31.5 mm (1.2 in)
7 January 1948
Feb
25.7 mm (1.0 in)
2 February 1961
Mar
25.4 mm (1.0 in)
9 March 2026
Apr
22.6 mm (0.9 in)
24 April 1974
May
37.8 mm (1.5 in)
13 May 2015
Jun
43.2 mm (1.7 in)
6 June 1957
Jul
17.5 mm (0.7 in)
3 July 1978
Aug
23.1 mm (0.9 in)
30 August 1947
Sep
24.9 mm (1.0 in)
24 September 1986
Oct
42.4 mm (1.7 in)
2 October 1957
Nov
21.1 mm (0.8 in)
29 November 1926
Dec
38.1 mm (1.5 in)
18 December 2007
Period of Record Coverage
1925 to 2026
Complete yearUnder 90 percent of days
102 years of record at Prosser, 1925 to 2026. 24 years have data for under 90 percent of days and are left out of rankings: 1925, 1926, 1927, 1928, 1929, 1930, 1932, 1934 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 72 complete years at Prosser, 1927 to 2022. Blue stripes are years cooler than the station's own mean of 10.8 C (51.5 F); red stripes are warmer. The coolest year was 1955, at 9.1 C (48.3 F), and the warmest was 2003, at 13.0 C (55.5 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Prosser as warming stripes, 1927 to 2022
Year
Annual mean temperature
Difference from the station mean
1927
10.3 C
-0.48 C
1929
9.3 C
-1.47 C
1930
10.2 C
-0.61 C
1931
11.3 C
+0.49 C
1932
10.8 C
0.00 C
1933
11.1 C
+0.26 C
1934
13.0 C
+2.15 C
1936
10.7 C
-0.15 C
1937
10.0 C
-0.80 C
1938
11.1 C
+0.24 C
1939
11.5 C
+0.67 C
1940
10.9 C
+0.13 C
1941
11.2 C
+0.35 C
1942
10.3 C
-0.47 C
1943
9.8 C
-1.01 C
1944
10.5 C
-0.36 C
1945
10.7 C
-0.15 C
1946
10.7 C
-0.11 C
1947
11.2 C
+0.34 C
1948
9.6 C
-1.21 C
1949
9.9 C
-0.89 C
1950
9.5 C
-1.27 C
1951
10.3 C
-0.50 C
1952
10.6 C
-0.25 C
1953
11.3 C
+0.51 C
1954
9.9 C
-0.94 C
1955
9.1 C
-1.74 C
1956
10.2 C
-0.62 C
1957
10.1 C
-0.74 C
1958
12.0 C
+1.18 C
1959
10.0 C
-0.78 C
1960
10.0 C
-0.81 C
1961
11.2 C
+0.42 C
1962
10.8 C
-0.03 C
1963
10.8 C
0.00 C
1965
11.3 C
+0.48 C
1966
11.6 C
+0.81 C
1967
12.1 C
+1.29 C
1968
10.8 C
-0.03 C
1969
9.7 C
-1.14 C
1970
10.1 C
-0.75 C
1971
10.2 C
-0.65 C
1972
10.1 C
-0.75 C
1973
10.6 C
-0.18 C
1974
10.5 C
-0.27 C
1975
9.7 C
-1.07 C
1976
10.0 C
-0.77 C
1977
10.4 C
-0.39 C
1978
10.1 C
-0.70 C
1979
10.1 C
-0.69 C
1980
9.8 C
-1.04 C
1981
10.7 C
-0.07 C
1982
10.0 C
-0.85 C
1983
10.7 C
-0.09 C
1985
9.2 C
-1.57 C
1988
11.5 C
+0.64 C
1991
11.1 C
+0.33 C
1997
11.9 C
+1.08 C
1999
12.2 C
+1.39 C
2000
11.0 C
+0.16 C
2001
11.2 C
+0.40 C
2002
11.9 C
+1.08 C
2003
13.0 C
+2.23 C
2004
12.7 C
+1.85 C
2005
12.1 C
+1.24 C
2006
12.3 C
+1.52 C
2007
11.9 C
+1.04 C
2016
12.5 C
+1.66 C
2018
12.2 C
+1.42 C
2019
10.5 C
-0.36 C
2020
12.4 C
+1.63 C
2022
10.9 C
+0.09 C
The annual mean temperature here has risen by 0.1 C (0.1 to 0.2) per decade over 1927 to 2022. In Fahrenheit: 0.3 F (0.1 to 0.4) per decade. The slope is a straight line fitted to 72 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Prosser
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (0.1 to 0.2) per decade
0.3 F (0.1 to 0.4) per decade
1927 to 2022
72
Rise
Mean daily maximum
0.05 C (-0.03 to 0.14) per decade
0.1 F (-0.1 to 0.2) per decade
1927 to 2022
72
Not clearly different from zero
Mean daily minimum
0.2 C (0.2 to 0.3) per decade
0.4 F (0.3 to 0.6) per decade
1927 to 2022
72
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
1925 to 2026
Yearly extremes at Prosser: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.6 C (114.1 F)
2021
38.9 C (102.0 F)
102
Coldest night (TNn)
-28.9 C (-20.0 F)
1930
-16.1 C (3.0 F)
102
Wettest day (Rx1day)
43.2 mm (1.7 in)
1957
17.0 mm (0.7 in)
102
Wettest five days (Rx5day)
52.3 mm (2.1 in)
1957
26.9 mm (1.1 in)
102
Longest dry spell (CDD)
152 days
1936
53 days
102
Hottest day (TXx)
The hottest day of the year at Prosser, 1925 to 2026. The record is 45.6 C (114.1 F) in 2021, marked on the chart; the median year is 38.9 C (102.0 F).
Hottest day (TXx) at Prosser by year
Year
Hottest day (TXx)
1925
37.2 C (99.0 F)
1926
40.0 C (104.0 F)
1927
39.4 C (102.9 F)
1928
38.9 C (102.0 F)
1929
40.0 C (104.0 F)
1930
39.4 C (102.9 F)
1931
40.0 C (104.0 F)
1932
37.8 C (100.0 F)
1933
38.9 C (102.0 F)
1934
40.6 C (105.1 F)
1935
39.4 C (102.9 F)
1936
39.4 C (102.9 F)
1937
39.4 C (102.9 F)
1938
41.7 C (107.1 F)
1939
43.3 C (109.9 F)
1940
38.3 C (100.9 F)
1941
41.7 C (107.1 F)
1942
39.4 C (102.9 F)
1943
37.2 C (99.0 F)
1944
38.9 C (102.0 F)
1945
37.8 C (100.0 F)
1946
38.3 C (100.9 F)
1947
36.7 C (98.1 F)
1948
38.9 C (102.0 F)
1949
37.8 C (100.0 F)
1950
36.7 C (98.1 F)
1951
38.3 C (100.9 F)
1952
38.3 C (100.9 F)
1953
37.2 C (99.0 F)
1954
35.6 C (96.1 F)
1955
37.2 C (99.0 F)
1956
37.8 C (100.0 F)
1957
35.6 C (96.1 F)
1958
38.3 C (100.9 F)
1959
39.4 C (102.9 F)
1960
39.4 C (102.9 F)
1961
38.9 C (102.0 F)
1962
37.8 C (100.0 F)
1963
36.7 C (98.1 F)
1964
38.9 C (102.0 F)
1965
38.9 C (102.0 F)
1966
36.1 C (97.0 F)
1967
38.9 C (102.0 F)
1968
40.6 C (105.1 F)
1969
37.2 C (99.0 F)
1970
38.3 C (100.9 F)
1971
40.6 C (105.1 F)
1972
39.4 C (102.9 F)
1973
37.2 C (99.0 F)
1974
36.7 C (98.1 F)
1975
40.0 C (104.0 F)
1976
36.1 C (97.0 F)
1977
38.3 C (100.9 F)
1978
38.3 C (100.9 F)
1979
40.0 C (104.0 F)
1980
37.2 C (99.0 F)
1981
37.8 C (100.0 F)
1982
38.3 C (100.9 F)
1983
37.8 C (100.0 F)
1984
37.2 C (99.0 F)
1985
37.8 C (100.0 F)
1986
39.4 C (102.9 F)
1987
38.3 C (100.9 F)
1988
38.3 C (100.9 F)
1989
36.7 C (98.1 F)
1990
40.0 C (104.0 F)
1991
37.8 C (100.0 F)
1992
40.6 C (105.1 F)
1993
37.2 C (99.0 F)
1994
40.6 C (105.1 F)
1995
32.8 C (91.0 F)
1996
35.6 C (96.1 F)
1997
38.9 C (102.0 F)
1998
42.2 C (108.0 F)
1999
40.6 C (105.1 F)
2000
40.6 C (105.1 F)
2001
40.6 C (105.1 F)
2002
43.9 C (111.0 F)
2003
40.0 C (104.0 F)
2004
39.4 C (102.9 F)
2005
38.9 C (102.0 F)
2006
42.2 C (108.0 F)
2007
41.1 C (106.0 F)
2008
40.0 C (104.0 F)
2009
41.1 C (106.0 F)
2010
38.3 C (100.9 F)
2011
36.7 C (98.1 F)
2012
40.0 C (104.0 F)
2013
41.1 C (106.0 F)
2014
36.1 C (97.0 F)
2015
41.7 C (107.1 F)
2016
39.4 C (102.9 F)
2017
40.0 C (104.0 F)
2018
40.0 C (104.0 F)
2019
40.0 C (104.0 F)
2020
41.7 C (107.1 F)
2021
45.6 C (114.1 F)
2022
42.8 C (109.0 F)
2023
40.6 C (105.1 F)
2024
41.1 C (106.0 F)
2025
38.9 C (102.0 F)
2026
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at Prosser, 1925 to 2026. The record is -28.9 C (-20.0 F) in 1930, marked on the chart; the median year is -16.1 C (3.0 F).
Coldest night (TNn) at Prosser by year
Year
Coldest night (TNn)
1925
5.6 C (42.1 F)
1926
-17.8 C (0.0 F)
1927
-18.3 C (-0.9 F)
1928
-13.9 C (7.0 F)
1929
-26.1 C (-15.0 F)
1930
-28.9 C (-20.0 F)
1931
-18.3 C (-0.9 F)
1932
-21.7 C (-7.1 F)
1933
-22.2 C (-8.0 F)
1934
-5.6 C (21.9 F)
1935
-21.1 C (-6.0 F)
1936
-20.0 C (-4.0 F)
1937
-25.6 C (-14.1 F)
1938
-13.3 C (8.1 F)
1939
-12.2 C (10.0 F)
1940
-14.4 C (6.1 F)
1941
-11.1 C (12.0 F)
1942
-19.4 C (-2.9 F)
1943
-21.7 C (-7.1 F)
1944
-13.9 C (7.0 F)
1945
-13.3 C (8.1 F)
1946
-12.2 C (10.0 F)
1947
-17.8 C (0.0 F)
1948
-16.1 C (3.0 F)
1949
-22.2 C (-8.0 F)
1950
-28.9 C (-20.0 F)
1951
-17.2 C (1.0 F)
1952
-15.0 C (5.0 F)
1953
-6.1 C (21.0 F)
1954
-26.1 C (-15.0 F)
1955
-17.8 C (0.0 F)
1956
-24.4 C (-11.9 F)
1957
-27.8 C (-18.0 F)
1958
-12.2 C (10.0 F)
1959
-18.3 C (-0.9 F)
1960
-17.8 C (0.0 F)
1961
-13.9 C (7.0 F)
1962
-16.1 C (3.0 F)
1963
-18.3 C (-0.9 F)
1964
-21.7 C (-7.1 F)
1965
-12.2 C (10.0 F)
1966
-6.7 C (19.9 F)
1967
-12.8 C (9.0 F)
1968
-23.9 C (-11.0 F)
1969
-21.1 C (-6.0 F)
1970
-15.0 C (5.0 F)
1971
-11.7 C (10.9 F)
1972
-21.7 C (-7.1 F)
1973
-17.2 C (1.0 F)
1974
-21.1 C (-6.0 F)
1975
-11.1 C (12.0 F)
1976
-13.3 C (8.1 F)
1977
-15.6 C (3.9 F)
1978
-21.7 C (-7.1 F)
1979
-22.2 C (-8.0 F)
1980
-20.0 C (-4.0 F)
1981
-12.2 C (10.0 F)
1982
-22.2 C (-8.0 F)
1983
-23.3 C (-9.9 F)
1984
-17.2 C (1.0 F)
1985
-21.7 C (-7.1 F)
1986
-10.0 C (14.0 F)
1987
-11.1 C (12.0 F)
1988
-11.1 C (12.0 F)
1989
-18.9 C (-2.0 F)
1990
-22.8 C (-9.0 F)
1991
-13.3 C (8.1 F)
1992
-11.1 C (12.0 F)
1993
-19.4 C (-2.9 F)
1994
-14.4 C (6.1 F)
1995
2.2 C (36.0 F)
1996
-17.8 C (0.0 F)
1997
-16.1 C (3.0 F)
1998
-20.6 C (-5.1 F)
1999
-7.8 C (18.0 F)
2000
-12.8 C (9.0 F)
2001
-13.3 C (8.1 F)
2002
-12.2 C (10.0 F)
2003
-10.6 C (12.9 F)
2004
-22.2 C (-8.0 F)
2005
-13.9 C (7.0 F)
2006
-11.1 C (12.0 F)
2007
-16.1 C (3.0 F)
2008
-12.8 C (9.0 F)
2009
-16.7 C (1.9 F)
2010
-16.1 C (3.0 F)
2011
-17.8 C (0.0 F)
2012
-11.1 C (12.0 F)
2013
-16.1 C (3.0 F)
2014
-15.0 C (5.0 F)
2015
-11.7 C (10.9 F)
2016
-17.8 C (0.0 F)
2017
-17.8 C (0.0 F)
2018
-10.6 C (12.9 F)
2019
-17.2 C (1.0 F)
2020
-10.6 C (12.9 F)
2021
-11.1 C (12.0 F)
2022
-16.1 C (3.0 F)
2023
-16.1 C (3.0 F)
2024
-17.2 C (1.0 F)
2025
-11.7 C (10.9 F)
2026
-7.8 C (18.0 F)
Wettest day (Rx1day)
The wettest day of the year at Prosser, 1925 to 2026. The record is 43.2 mm (1.7 in) in 1957, marked on the chart; the median year is 17.0 mm (0.7 in).
Wettest day (Rx1day) at Prosser by year
Year
Wettest day (Rx1day)
1925
0.0 mm (0.00 in)
1926
21.1 mm (0.8 in)
1927
18.5 mm (0.7 in)
1928
11.9 mm (0.5 in)
1929
13.5 mm (0.5 in)
1930
9.1 mm (0.36 in)
1931
13.5 mm (0.5 in)
1932
14.7 mm (0.6 in)
1933
10.2 mm (0.4 in)
1934
17.0 mm (0.7 in)
1935
9.4 mm (0.37 in)
1936
12.2 mm (0.5 in)
1937
14.7 mm (0.6 in)
1938
29.2 mm (1.1 in)
1939
13.2 mm (0.5 in)
1940
17.3 mm (0.7 in)
1941
21.1 mm (0.8 in)
1942
20.3 mm (0.8 in)
1943
14.5 mm (0.6 in)
1944
20.1 mm (0.8 in)
1945
15.5 mm (0.6 in)
1946
11.7 mm (0.5 in)
1947
23.1 mm (0.9 in)
1948
31.5 mm (1.2 in)
1949
17.0 mm (0.7 in)
1950
33.3 mm (1.3 in)
1951
14.5 mm (0.6 in)
1952
7.6 mm (0.30 in)
1953
17.8 mm (0.7 in)
1954
10.9 mm (0.4 in)
1955
16.3 mm (0.6 in)
1956
20.3 mm (0.8 in)
1957
43.2 mm (1.7 in)
1958
13.0 mm (0.5 in)
1959
26.4 mm (1.0 in)
1960
15.5 mm (0.6 in)
1961
25.7 mm (1.0 in)
1962
10.7 mm (0.4 in)
1963
16.0 mm (0.6 in)
1964
19.6 mm (0.8 in)
1965
9.1 mm (0.36 in)
1966
19.6 mm (0.8 in)
1967
10.4 mm (0.4 in)
1968
13.5 mm (0.5 in)
1969
11.7 mm (0.5 in)
1970
23.1 mm (0.9 in)
1971
16.3 mm (0.6 in)
1972
22.6 mm (0.9 in)
1973
16.0 mm (0.6 in)
1974
22.6 mm (0.9 in)
1975
17.3 mm (0.7 in)
1976
6.6 mm (0.26 in)
1977
21.6 mm (0.9 in)
1978
22.1 mm (0.9 in)
1979
17.3 mm (0.7 in)
1980
18.0 mm (0.7 in)
1981
16.8 mm (0.7 in)
1982
27.7 mm (1.1 in)
1983
15.0 mm (0.6 in)
1984
20.6 mm (0.8 in)
1985
18.8 mm (0.7 in)
1986
24.9 mm (1.0 in)
1987
15.5 mm (0.6 in)
1988
16.0 mm (0.6 in)
1989
11.7 mm (0.5 in)
1990
19.8 mm (0.8 in)
1991
21.3 mm (0.8 in)
1992
19.6 mm (0.8 in)
1993
10.2 mm (0.4 in)
1994
16.0 mm (0.6 in)
1995
3.0 mm (0.12 in)
1996
16.5 mm (0.6 in)
1997
15.2 mm (0.6 in)
1998
10.9 mm (0.4 in)
1999
15.2 mm (0.6 in)
2000
19.1 mm (0.8 in)
2001
13.0 mm (0.5 in)
2002
17.8 mm (0.7 in)
2003
17.8 mm (0.7 in)
2004
18.3 mm (0.7 in)
2005
17.0 mm (0.7 in)
2006
19.1 mm (0.8 in)
2007
38.1 mm (1.5 in)
2008
17.0 mm (0.7 in)
2009
18.8 mm (0.7 in)
2010
27.4 mm (1.1 in)
2011
26.7 mm (1.1 in)
2012
25.4 mm (1.0 in)
2013
17.8 mm (0.7 in)
2014
14.2 mm (0.6 in)
2015
37.8 mm (1.5 in)
2016
25.4 mm (1.0 in)
2017
16.3 mm (0.6 in)
2018
11.7 mm (0.5 in)
2019
16.0 mm (0.6 in)
2020
11.2 mm (0.4 in)
2021
10.7 mm (0.4 in)
2022
18.8 mm (0.7 in)
2023
11.9 mm (0.5 in)
2024
23.9 mm (0.9 in)
2025
16.5 mm (0.6 in)
2026
25.4 mm (1.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Prosser, 1925 to 2026. The record is 52.3 mm (2.1 in) in 1957, marked on the chart; the median year is 26.9 mm (1.1 in).
Wettest five days (Rx5day) at Prosser by year
Year
Wettest five days (Rx5day)
1925
0.0 mm (0.00 in)
1926
31.5 mm (1.2 in)
1927
29.4 mm (1.2 in)
1928
33.2 mm (1.3 in)
1929
20.7 mm (0.8 in)
1930
19.0 mm (0.7 in)
1931
25.4 mm (1.0 in)
1932
22.3 mm (0.9 in)
1933
20.1 mm (0.8 in)
1934
27.2 mm (1.1 in)
1935
19.3 mm (0.8 in)
1936
24.1 mm (0.9 in)
1937
29.3 mm (1.2 in)
1938
40.6 mm (1.6 in)
1939
14.7 mm (0.6 in)
1940
36.1 mm (1.4 in)
1941
29.2 mm (1.1 in)
1942
30.0 mm (1.2 in)
1943
29.7 mm (1.2 in)
1944
29.5 mm (1.2 in)
1945
27.6 mm (1.1 in)
1946
18.0 mm (0.7 in)
1947
25.7 mm (1.0 in)
1948
36.6 mm (1.4 in)
1949
22.9 mm (0.9 in)
1950
36.1 mm (1.4 in)
1951
33.8 mm (1.3 in)
1952
13.4 mm (0.5 in)
1953
29.5 mm (1.2 in)
1954
21.6 mm (0.9 in)
1955
26.2 mm (1.0 in)
1956
26.4 mm (1.0 in)
1957
52.3 mm (2.1 in)
1958
34.6 mm (1.4 in)
1959
35.4 mm (1.4 in)
1960
23.1 mm (0.9 in)
1961
36.7 mm (1.4 in)
1962
30.1 mm (1.2 in)
1963
23.1 mm (0.9 in)
1964
49.8 mm (2.0 in)
1965
12.4 mm (0.5 in)
1966
33.5 mm (1.3 in)
1967
16.8 mm (0.7 in)
1968
24.6 mm (1.0 in)
1969
21.9 mm (0.9 in)
1970
43.7 mm (1.7 in)
1971
25.4 mm (1.0 in)
1972
30.0 mm (1.2 in)
1973
34.0 mm (1.3 in)
1974
27.9 mm (1.1 in)
1975
28.2 mm (1.1 in)
1976
13.9 mm (0.5 in)
1977
49.6 mm (2.0 in)
1978
31.1 mm (1.2 in)
1979
27.2 mm (1.1 in)
1980
30.0 mm (1.2 in)
1981
22.3 mm (0.9 in)
1982
30.5 mm (1.2 in)
1983
21.9 mm (0.9 in)
1984
22.1 mm (0.9 in)
1985
22.9 mm (0.9 in)
1986
29.5 mm (1.2 in)
1987
36.6 mm (1.4 in)
1988
23.9 mm (0.9 in)
1989
19.5 mm (0.8 in)
1990
21.1 mm (0.8 in)
1991
27.1 mm (1.1 in)
1992
27.7 mm (1.1 in)
1993
14.2 mm (0.6 in)
1994
26.9 mm (1.1 in)
1995
7.4 mm (0.29 in)
1996
22.8 mm (0.9 in)
1997
22.9 mm (0.9 in)
1998
16.2 mm (0.6 in)
1999
19.9 mm (0.8 in)
2000
20.8 mm (0.8 in)
2001
22.4 mm (0.9 in)
2002
35.3 mm (1.4 in)
2003
29.5 mm (1.2 in)
2004
47.7 mm (1.9 in)
2005
43.2 mm (1.7 in)
2006
46.3 mm (1.8 in)
2007
38.1 mm (1.5 in)
2008
17.0 mm (0.7 in)
2009
26.2 mm (1.0 in)
2010
34.9 mm (1.4 in)
2011
12.8 mm (0.5 in)
2012
30.0 mm (1.2 in)
2013
29.5 mm (1.2 in)
2014
16.3 mm (0.6 in)
2015
49.5 mm (1.9 in)
2016
29.2 mm (1.1 in)
2017
23.9 mm (0.9 in)
2018
21.1 mm (0.8 in)
2019
24.1 mm (0.9 in)
2020
17.3 mm (0.7 in)
2021
18.9 mm (0.7 in)
2022
22.1 mm (0.9 in)
2023
23.4 mm (0.9 in)
2024
42.2 mm (1.7 in)
2025
28.2 mm (1.1 in)
2026
26.9 mm (1.1 in)
Longest dry spell (CDD)
The longest dry spell of the year at Prosser, 1925 to 2026. The record is 152 days in 1936, marked on the chart; the median year is 53 days.
Longest dry spell (CDD) at Prosser by year
Year
Longest dry spell (CDD)
1925
31 days
1926
31 days
1927
35 days
1928
30 days
1929
62 days
1930
79 days
1931
77 days
1932
49 days
1933
31 days
1934
56 days
1935
54 days
1936
152 days
1937
35 days
1938
101 days
1939
53 days
1940
53 days
1941
30 days
1942
63 days
1943
64 days
1944
91 days
1945
69 days
1946
47 days
1947
33 days
1948
31 days
1949
84 days
1950
76 days
1951
49 days
1952
65 days
1953
55 days
1954
67 days
1955
48 days
1956
49 days
1957
65 days
1958
50 days
1959
61 days
1960
48 days
1961
55 days
1962
49 days
1963
70 days
1964
64 days
1965
56 days
1966
56 days
1967
80 days
1968
52 days
1969
85 days
1970
52 days
1971
42 days
1972
36 days
1973
73 days
1974
74 days
1975
49 days
1976
59 days
1977
45 days
1978
53 days
1979
62 days
1980
66 days
1981
74 days
1982
41 days
1983
28 days
1984
82 days
1985
54 days
1986
29 days
1987
51 days
1988
66 days
1989
47 days
1990
67 days
1991
98 days
1992
42 days
1993
85 days
1994
30 days
1995
21 days
1996
15 days
1997
29 days
1998
30 days
1999
67 days
2000
82 days
2001
42 days
2002
87 days
2003
72 days
2004
39 days
2005
43 days
2006
97 days
2007
33 days
2008
39 days
2009
27 days
2010
32 days
2011
1 day
2012
44 days
2013
57 days
2014
40 days
2015
78 days
2016
25 days
2017
57 days
2018
75 days
2019
36 days
2020
102 days
2021
117 days
2022
90 days
2023
41 days
2024
50 days
2025
72 days
2026
46 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
72 years with a frost
Across 72 years with a frost, the median last spring frost at Prosser falls on 4 May and the median first autumn frost on 13 October, which leaves a median of 159 days between them.
In 1972 to 2022 the median growing season was 177 days. That is 24 days more than in 1927 to 1958.
Fitted over all years, the growing season changes by +6.4 days per decade at this station.
Frost dates and growing season at Prosser
Measure
Median, all years
Earliest period (1927 to 1958)
Recent period (1972 to 2022)
Recent against earliest
Fitted trend
Last spring frost
4 May
7 May
23 April
14 days earlier
-4.6 days per decade
First autumn frost
13 October
10 October
17 October
7 days later
+1.8 days per decade
Growing days
159 days
153 days
177 days
24 days more
+6.4 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
82 years, 1927 to 2025
A day with at least 16.6 mm (0.7 in) of rain is expected about once in 2 years. A day with at least 37.9 mm (1.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Prosser: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
16.6 mm (0.7 in)
5 years
22.1 mm (0.9 in)
10 years
25.8 mm (1.0 in)
25 years
30.6 mm (1.2 in)
50 years
34.3 mm (1.4 in)
100 years
37.9 mm (1.5 in)
Longer than the 82 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, 82 years of values from 1927 to 2025.
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: 43.2 mm (1.7 in) in 1957; 38.1 mm (1.5 in) in 2007; 33.3 mm (1.3 in) in 1950.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Prosser, at 1968 and 1997. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1968 ran 0.3 C (0.5 F) lower than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1997 ran 0.8 C (1.4 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Prosser, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1968
-0.3
-0.5
likely
5
1997
+0.8
+1.4
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 Prosser standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Prosser 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.