Record envelope, standing records and threshold days for Williamson (USC00469605), West Virginia, United States, with 94 years of record.
Key Facts for Williamson
Williamson (USC00469605) is a weather station in West Virginia, United States at 37.67 latitude and -82.28 longitude, 204 m (670 ft) above sea level.
The station reports from 1900 to 1993, 94 years of record.
1,464 records set at Williamson still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Williamson tied a daily record high minimum temperature of 22.2 C (72.0 F) on 10 July 1993.
About the Station
Location: West Virginia, United States, 37.67 latitude, -82.28 longitude.
Elevation: 204 m (670 ft).
Period of record: 1900 to 1993, 94 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 Williamson. 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 Williamson, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
27.8 C (82.0 F)
-27.8 C (-18.0 F)
n/a
n/a
Feb
35.0 C (95.0 F)
-22.2 C (-8.0 F)
n/a
n/a
Mar
32.2 C (90.0 F)
-20.0 C (-4.0 F)
n/a
n/a
Apr
35.6 C (96.1 F)
-7.8 C (18.0 F)
n/a
n/a
May
37.2 C (99.0 F)
-1.1 C (30.0 F)
n/a
n/a
Jun
40.6 C (105.1 F)
2.8 C (37.0 F)
n/a
n/a
Jul
40.6 C (105.1 F)
7.2 C (45.0 F)
n/a
n/a
Aug
41.7 C (107.1 F)
5.6 C (42.1 F)
n/a
n/a
Sep
40.0 C (104.0 F)
0.6 C (33.1 F)
n/a
n/a
Oct
36.7 C (98.1 F)
-9.4 C (15.1 F)
n/a
n/a
Nov
31.1 C (88.0 F)
-14.4 C (6.1 F)
n/a
n/a
Dec
27.8 C (82.0 F)
-23.3 C (-9.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Williamson still stand. 1930 holds the most, with 67.
Standing records at Williamson by the year they were set
Year set
Standing records
1900
4
1901
12
1902
17
1903
21
1904
14
1905
7
1906
11
1907
16
1908
16
1909
15
1910
13
1911
9
1912
13
1913
10
1914
26
1915
16
1916
19
1917
23
1918
31
1919
14
1920
19
1921
5
1922
5
1923
17
1924
14
1925
9
1926
26
1927
12
1928
29
1929
59
1930
67
1931
33
1932
13
1933
15
1934
18
1935
12
1936
16
1937
13
1938
4
1939
23
1940
23
1941
18
1942
11
1943
7
1944
6
1945
18
1946
15
1947
30
1948
18
1949
17
1950
21
1951
14
1952
12
1953
21
1954
21
1955
13
1956
14
1957
11
1958
11
1959
22
1960
20
1961
21
1962
20
1963
21
1964
15
1965
9
1966
9
1967
17
1968
7
1969
9
1970
12
1971
10
1972
10
1973
16
1974
12
1975
8
1976
18
1977
22
1978
7
1979
12
1980
9
1981
3
1982
7
1983
11
1984
11
1985
15
1986
8
1987
12
1988
25
1989
15
1990
10
1991
11
1992
10
1993
3
All-Time Record Progression
6 new records
6 all-time records were set at Williamson between 2 August 1945 and 23 December 1989. Each dot is a new record.
When Williamson set new all-time records
Date
Kind
Detail
1945-08-02
Record daily precipitation
Record daily precipitation 117.3 mm (4.6 in)
1962-12-13
Record low minimum temperature
Record low minimum temperature -23.3 C (-9.9 F)
1963-01-24
Record low minimum temperature
Record low minimum temperature -23.9 C (-11.0 F)
1985-01-22
Record low minimum temperature
Record low minimum temperature -27.8 C (-18.0 F)
1988-08-18
Record high maximum temperature
Record high maximum temperature 41.7 C (107.1 F)
1989-12-23
Record low maximum temperature
Record low maximum temperature -15.6 C (3.9 F)
Wettest Day of Each Month
Aug: 117.3 mm (4.6 in)
The wettest day on record for each calendar month at Williamson. The most was 117.3 mm (4.6 in) on 2 August 1945.
Record daily precipitation for each month at Williamson
Month
Record daily precipitation (mm)
Date
Jan
56.4 mm (2.2 in)
28 January 1918
Feb
62.5 mm (2.5 in)
3 February 1939
Mar
94.0 mm (3.7 in)
12 March 1963
Apr
90.9 mm (3.6 in)
1 April 1908
May
67.3 mm (2.6 in)
30 May 1904
Jun
100.3 mm (3.9 in)
14 June 1971
Jul
95.3 mm (3.8 in)
13 July 1929
Aug
117.3 mm (4.6 in)
2 August 1945
Sep
88.9 mm (3.5 in)
29 September 1964
Oct
94.0 mm (3.7 in)
2 October 1911
Nov
71.1 mm (2.8 in)
21 November 1900
Dec
80.0 mm (3.1 in)
9 December 1978
Period of Record Coverage
1900 to 1993
Complete yearUnder 90 percent of days
94 years of record at Williamson, 1900 to 1993. 23 years have data for under 90 percent of days and are left out of rankings: 1900, 1905, 1925, 1926, 1968, 1969, 1970, 1971 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 71 complete years at Williamson, 1901 to 1985. Blue stripes are years cooler than the station's own mean of 13.8 C (56.8 F); red stripes are warmer. The coolest year was 1924, at 11.7 C (53.1 F), and the warmest was 1931, at 15.1 C (59.2 F). The strongest colour marks a difference of 2.1 C (3.8 F).
Annual mean temperature at Williamson as warming stripes, 1901 to 1985
Year
Annual mean temperature
Difference from the station mean
1901
13.2 C
-0.55 C
1902
13.2 C
-0.57 C
1903
13.0 C
-0.76 C
1906
13.8 C
+0.01 C
1908
15.0 C
+1.20 C
1909
14.7 C
+0.95 C
1910
13.9 C
+0.12 C
1911
14.9 C
+1.17 C
1912
12.5 C
-1.25 C
1913
13.6 C
-0.22 C
1914
12.0 C
-1.81 C
1915
13.5 C
-0.31 C
1916
14.0 C
+0.24 C
1917
12.1 C
-1.68 C
1918
13.5 C
-0.28 C
1919
14.0 C
+0.22 C
1920
12.4 C
-1.36 C
1921
14.4 C
+0.62 C
1922
13.7 C
-0.08 C
1923
13.2 C
-0.56 C
1924
11.7 C
-2.07 C
1925
13.0 C
-0.78 C
1927
15.0 C
+1.24 C
1928
14.2 C
+0.42 C
1929
13.3 C
-0.51 C
1930
15.1 C
+1.31 C
1931
15.1 C
+1.32 C
1932
14.1 C
+0.37 C
1933
14.5 C
+0.73 C
1934
14.0 C
+0.24 C
1935
13.5 C
-0.28 C
1936
13.8 C
+0.05 C
1937
13.4 C
-0.38 C
1938
14.4 C
+0.66 C
1939
14.9 C
+1.15 C
1940
13.1 C
-0.66 C
1941
14.3 C
+0.52 C
1942
13.9 C
+0.11 C
1943
13.5 C
-0.26 C
1944
13.9 C
+0.12 C
1945
14.3 C
+0.55 C
1946
15.0 C
+1.18 C
1947
13.7 C
-0.07 C
1948
14.0 C
+0.23 C
1949
14.8 C
+1.07 C
1950
13.7 C
-0.12 C
1951
13.8 C
+0.00 C
1952
14.3 C
+0.56 C
1953
14.5 C
+0.77 C
1954
14.2 C
+0.42 C
1955
14.1 C
+0.35 C
1956
13.8 C
+0.06 C
1957
14.5 C
+0.73 C
1958
12.7 C
-1.06 C
1959
14.2 C
+0.44 C
1960
13.2 C
-0.56 C
1961
13.8 C
+0.04 C
1962
13.6 C
-0.22 C
1963
12.8 C
-1.02 C
1964
13.7 C
-0.06 C
1965
14.1 C
+0.31 C
1966
13.0 C
-0.79 C
1967
13.4 C
-0.39 C
1972
13.7 C
-0.05 C
1973
14.1 C
+0.31 C
1974
13.8 C
-0.01 C
1975
14.1 C
+0.32 C
1976
12.3 C
-1.45 C
1981
13.1 C
-0.66 C
1983
13.9 C
+0.11 C
1985
14.1 C
+0.28 C
The fitted trend in annual mean temperature here over 1901 to 1985 is 0.02 C (-0.06 to 0.10) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.03 F (-0.12 to 0.18) 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 Williamson
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.02 C (-0.06 to 0.10) per decade
0.03 F (-0.12 to 0.18) per decade
1901 to 1985
71
Not clearly different from zero
Mean daily maximum
0.2 C (0.1 to 0.3) per decade
0.3 F (0.1 to 0.5) per decade
1901 to 1985
71
Rise
Mean daily minimum
-0.13 C (-0.22 to -0.04) per decade
-0.2 F (-0.4 to -0.1) per decade
1901 to 1985
71
Fall
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
1900 to 1993
Yearly extremes at Williamson: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.7 C (107.1 F)
1988
36.7 C (98.1 F)
94
Coldest night (TNn)
-27.8 C (-18.0 F)
1985
-16.1 C (3.0 F)
94
Wettest day (Rx1day)
117.3 mm (4.6 in)
1945
52.8 mm (2.1 in)
94
Wettest five days (Rx5day)
186.2 mm (7.3 in)
1945
93.0 mm (3.7 in)
94
Longest dry spell (CDD)
32 days
1903
18 days
94
Hottest day (TXx)
The hottest day of the year at Williamson, 1900 to 1993. The record is 41.7 C (107.1 F) in 1988, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Williamson by year
Year
Hottest day (TXx)
1900
36.1 C (97.0 F)
1901
36.1 C (97.0 F)
1902
35.6 C (96.1 F)
1903
36.7 C (98.1 F)
1904
34.4 C (93.9 F)
1905
35.0 C (95.0 F)
1906
33.9 C (93.0 F)
1907
34.4 C (93.9 F)
1908
36.1 C (97.0 F)
1909
36.7 C (98.1 F)
1910
33.9 C (93.0 F)
1911
38.3 C (100.9 F)
1912
34.4 C (93.9 F)
1913
35.6 C (96.1 F)
1914
36.1 C (97.0 F)
1915
34.4 C (93.9 F)
1916
33.9 C (93.0 F)
1917
35.6 C (96.1 F)
1918
37.2 C (99.0 F)
1919
33.9 C (93.0 F)
1920
32.2 C (90.0 F)
1921
33.3 C (91.9 F)
1922
32.8 C (91.0 F)
1923
32.8 C (91.0 F)
1924
32.8 C (91.0 F)
1925
33.3 C (91.9 F)
1926
36.1 C (97.0 F)
1927
36.1 C (97.0 F)
1928
35.6 C (96.1 F)
1929
36.7 C (98.1 F)
1930
40.6 C (105.1 F)
1931
40.0 C (104.0 F)
1932
37.8 C (100.0 F)
1933
38.3 C (100.9 F)
1934
38.9 C (102.0 F)
1935
35.6 C (96.1 F)
1936
38.9 C (102.0 F)
1937
35.6 C (96.1 F)
1938
35.0 C (95.0 F)
1939
37.8 C (100.0 F)
1940
37.2 C (99.0 F)
1941
38.3 C (100.9 F)
1942
36.7 C (98.1 F)
1943
36.7 C (98.1 F)
1944
36.7 C (98.1 F)
1945
37.2 C (99.0 F)
1946
35.6 C (96.1 F)
1947
37.2 C (99.0 F)
1948
37.8 C (100.0 F)
1949
37.2 C (99.0 F)
1950
35.0 C (95.0 F)
1951
37.2 C (99.0 F)
1952
38.3 C (100.9 F)
1953
40.0 C (104.0 F)
1954
40.0 C (104.0 F)
1955
40.0 C (104.0 F)
1956
35.0 C (95.0 F)
1957
37.8 C (100.0 F)
1958
36.1 C (97.0 F)
1959
38.9 C (102.0 F)
1960
37.8 C (100.0 F)
1961
36.1 C (97.0 F)
1962
38.3 C (100.9 F)
1963
36.7 C (98.1 F)
1964
37.8 C (100.0 F)
1965
38.3 C (100.9 F)
1966
37.8 C (100.0 F)
1967
36.1 C (97.0 F)
1968
37.8 C (100.0 F)
1969
37.8 C (100.0 F)
1970
37.8 C (100.0 F)
1971
36.7 C (98.1 F)
1972
36.7 C (98.1 F)
1973
37.2 C (99.0 F)
1974
37.2 C (99.0 F)
1975
36.1 C (97.0 F)
1976
35.6 C (96.1 F)
1977
37.2 C (99.0 F)
1978
36.1 C (97.0 F)
1979
36.1 C (97.0 F)
1980
37.8 C (100.0 F)
1981
36.7 C (98.1 F)
1982
35.6 C (96.1 F)
1983
40.0 C (104.0 F)
1984
36.7 C (98.1 F)
1985
36.7 C (98.1 F)
1986
38.3 C (100.9 F)
1987
38.9 C (102.0 F)
1988
41.7 C (107.1 F)
1989
36.7 C (98.1 F)
1990
36.7 C (98.1 F)
1991
36.1 C (97.0 F)
1992
36.7 C (98.1 F)
1993
39.4 C (102.9 F)
Coldest night (TNn)
The coldest night of the year at Williamson, 1900 to 1993. The record is -27.8 C (-18.0 F) in 1985, marked on the chart; the median year is -16.1 C (3.0 F).
Coldest night (TNn) at Williamson by year
Year
Coldest night (TNn)
1900
-7.8 C (18.0 F)
1901
-15.0 C (5.0 F)
1902
-13.9 C (7.0 F)
1903
-17.2 C (1.0 F)
1904
-17.8 C (0.0 F)
1905
-22.2 C (-8.0 F)
1906
-12.8 C (9.0 F)
1907
-15.6 C (3.9 F)
1908
-12.2 C (10.0 F)
1909
-18.3 C (-0.9 F)
1910
-11.7 C (10.9 F)
1911
-11.7 C (10.9 F)
1912
-17.2 C (1.0 F)
1913
-12.2 C (10.0 F)
1914
-17.2 C (1.0 F)
1915
-9.4 C (15.1 F)
1916
-15.0 C (5.0 F)
1917
-17.8 C (0.0 F)
1918
-17.8 C (0.0 F)
1919
-11.7 C (10.9 F)
1920
-16.1 C (3.0 F)
1921
-6.7 C (19.9 F)
1922
-10.6 C (12.9 F)
1923
-12.8 C (9.0 F)
1924
-17.8 C (0.0 F)
1925
-12.2 C (10.0 F)
1926
-15.6 C (3.9 F)
1927
-13.9 C (7.0 F)
1928
-18.3 C (-0.9 F)
1929
-16.1 C (3.0 F)
1930
-17.8 C (0.0 F)
1931
-10.0 C (14.0 F)
1932
-13.3 C (8.1 F)
1933
-16.1 C (3.0 F)
1934
-16.1 C (3.0 F)
1935
-18.9 C (-2.0 F)
1936
-21.1 C (-6.0 F)
1937
-12.8 C (9.0 F)
1938
-12.2 C (10.0 F)
1939
-11.7 C (10.9 F)
1940
-18.9 C (-2.0 F)
1941
-11.7 C (10.9 F)
1942
-17.2 C (1.0 F)
1943
-16.1 C (3.0 F)
1944
-13.3 C (8.1 F)
1945
-14.4 C (6.1 F)
1946
-12.8 C (9.0 F)
1947
-15.0 C (5.0 F)
1948
-19.4 C (-2.9 F)
1949
-8.9 C (16.0 F)
1950
-13.9 C (7.0 F)
1951
-15.0 C (5.0 F)
1952
-9.4 C (15.1 F)
1953
-14.4 C (6.1 F)
1954
-18.3 C (-0.9 F)
1955
-21.7 C (-7.1 F)
1956
-11.7 C (10.9 F)
1957
-20.6 C (-5.1 F)
1958
-18.9 C (-2.0 F)
1959
-18.3 C (-0.9 F)
1960
-16.7 C (1.9 F)
1961
-19.4 C (-2.9 F)
1962
-23.3 C (-9.9 F)
1963
-23.9 C (-11.0 F)
1964
-15.0 C (5.0 F)
1965
-17.8 C (0.0 F)
1966
-22.8 C (-9.0 F)
1967
-17.8 C (0.0 F)
1968
-16.7 C (1.9 F)
1969
-20.6 C (-5.1 F)
1970
-21.7 C (-7.1 F)
1971
-19.4 C (-2.9 F)
1972
-20.6 C (-5.1 F)
1973
-13.9 C (7.0 F)
1974
-10.0 C (14.0 F)
1975
-12.8 C (9.0 F)
1976
-15.0 C (5.0 F)
1977
-23.9 C (-11.0 F)
1978
-22.2 C (-8.0 F)
1979
-19.4 C (-2.9 F)
1980
-20.0 C (-4.0 F)
1981
-19.4 C (-2.9 F)
1982
-12.2 C (10.0 F)
1983
-15.0 C (5.0 F)
1984
-21.7 C (-7.1 F)
1985
-27.8 C (-18.0 F)
1986
-17.2 C (1.0 F)
1987
-9.4 C (15.1 F)
1988
-15.0 C (5.0 F)
1989
-22.2 C (-8.0 F)
1990
-15.0 C (5.0 F)
1991
-15.6 C (3.9 F)
1992
-15.0 C (5.0 F)
1993
-17.2 C (1.0 F)
Wettest day (Rx1day)
The wettest day of the year at Williamson, 1900 to 1993. The record is 117.3 mm (4.6 in) in 1945, marked on the chart; the median year is 52.8 mm (2.1 in).
Wettest day (Rx1day) at Williamson by year
Year
Wettest day (Rx1day)
1900
71.1 mm (2.8 in)
1901
78.7 mm (3.1 in)
1902
52.8 mm (2.1 in)
1903
61.0 mm (2.4 in)
1904
67.3 mm (2.6 in)
1905
61.5 mm (2.4 in)
1906
47.0 mm (1.9 in)
1907
44.5 mm (1.8 in)
1908
90.9 mm (3.6 in)
1909
90.9 mm (3.6 in)
1910
42.7 mm (1.7 in)
1911
94.0 mm (3.7 in)
1912
64.0 mm (2.5 in)
1913
54.4 mm (2.1 in)
1914
49.8 mm (2.0 in)
1915
71.1 mm (2.8 in)
1916
66.0 mm (2.6 in)
1917
62.5 mm (2.5 in)
1918
56.4 mm (2.2 in)
1919
68.6 mm (2.7 in)
1920
41.9 mm (1.6 in)
1921
44.7 mm (1.8 in)
1922
59.7 mm (2.4 in)
1923
37.1 mm (1.5 in)
1924
68.3 mm (2.7 in)
1925
38.1 mm (1.5 in)
1926
49.8 mm (2.0 in)
1927
32.5 mm (1.3 in)
1928
50.5 mm (2.0 in)
1929
95.3 mm (3.8 in)
1930
45.5 mm (1.8 in)
1931
51.8 mm (2.0 in)
1932
83.1 mm (3.3 in)
1933
42.2 mm (1.7 in)
1934
69.1 mm (2.7 in)
1935
64.3 mm (2.5 in)
1936
55.4 mm (2.2 in)
1937
71.4 mm (2.8 in)
1938
53.1 mm (2.1 in)
1939
87.9 mm (3.5 in)
1940
51.6 mm (2.0 in)
1941
46.7 mm (1.8 in)
1942
87.1 mm (3.4 in)
1943
35.6 mm (1.4 in)
1944
44.7 mm (1.8 in)
1945
117.3 mm (4.6 in)
1946
47.5 mm (1.9 in)
1947
101.6 mm (4.0 in)
1948
64.3 mm (2.5 in)
1949
47.5 mm (1.9 in)
1950
43.2 mm (1.7 in)
1951
43.4 mm (1.7 in)
1952
44.5 mm (1.8 in)
1953
54.6 mm (2.1 in)
1954
56.1 mm (2.2 in)
1955
52.8 mm (2.1 in)
1956
50.3 mm (2.0 in)
1957
40.6 mm (1.6 in)
1958
41.9 mm (1.6 in)
1959
41.1 mm (1.6 in)
1960
36.6 mm (1.4 in)
1961
66.0 mm (2.6 in)
1962
52.1 mm (2.1 in)
1963
94.0 mm (3.7 in)
1964
88.9 mm (3.5 in)
1965
35.6 mm (1.4 in)
1966
78.7 mm (3.1 in)
1967
41.7 mm (1.6 in)
1968
50.8 mm (2.0 in)
1969
54.4 mm (2.1 in)
1970
48.0 mm (1.9 in)
1971
100.3 mm (3.9 in)
1972
46.5 mm (1.8 in)
1973
43.4 mm (1.7 in)
1974
55.9 mm (2.2 in)
1975
41.4 mm (1.6 in)
1976
41.7 mm (1.6 in)
1977
43.2 mm (1.7 in)
1978
80.0 mm (3.1 in)
1979
50.8 mm (2.0 in)
1980
53.8 mm (2.1 in)
1981
54.6 mm (2.1 in)
1982
60.2 mm (2.4 in)
1983
45.7 mm (1.8 in)
1984
53.8 mm (2.1 in)
1985
39.6 mm (1.6 in)
1986
46.7 mm (1.8 in)
1987
49.3 mm (1.9 in)
1988
31.2 mm (1.2 in)
1989
77.5 mm (3.1 in)
1990
84.3 mm (3.3 in)
1991
61.5 mm (2.4 in)
1992
43.9 mm (1.7 in)
1993
47.2 mm (1.9 in)
Wettest five days (Rx5day)
The wettest five days of the year at Williamson, 1900 to 1993. The record is 186.2 mm (7.3 in) in 1945, marked on the chart; the median year is 93.0 mm (3.7 in).
Wettest five days (Rx5day) at Williamson by year
Year
Wettest five days (Rx5day)
1900
152.4 mm (6.0 in)
1901
151.1 mm (5.9 in)
1902
112.9 mm (4.4 in)
1903
86.3 mm (3.4 in)
1904
145.1 mm (5.7 in)
1905
65.8 mm (2.6 in)
1906
90.9 mm (3.6 in)
1907
125.3 mm (4.9 in)
1908
162.4 mm (6.4 in)
1909
119.3 mm (4.7 in)
1910
60.5 mm (2.4 in)
1911
110.3 mm (4.3 in)
1912
93.0 mm (3.7 in)
1913
89.5 mm (3.5 in)
1914
93.5 mm (3.7 in)
1915
81.2 mm (3.2 in)
1916
92.9 mm (3.7 in)
1917
107.8 mm (4.2 in)
1918
84.8 mm (3.3 in)
1919
91.9 mm (3.6 in)
1920
106.9 mm (4.2 in)
1921
74.9 mm (2.9 in)
1922
81.1 mm (3.2 in)
1923
61.4 mm (2.4 in)
1924
140.4 mm (5.5 in)
1925
70.4 mm (2.8 in)
1926
82.4 mm (3.2 in)
1927
60.9 mm (2.4 in)
1928
78.7 mm (3.1 in)
1929
133.9 mm (5.3 in)
1930
65.1 mm (2.6 in)
1931
94.8 mm (3.7 in)
1932
93.5 mm (3.7 in)
1933
70.9 mm (2.8 in)
1934
90.7 mm (3.6 in)
1935
120.9 mm (4.8 in)
1936
78.9 mm (3.1 in)
1937
90.8 mm (3.6 in)
1938
99.6 mm (3.9 in)
1939
137.0 mm (5.4 in)
1940
59.2 mm (2.3 in)
1941
105.9 mm (4.2 in)
1942
147.6 mm (5.8 in)
1943
80.5 mm (3.2 in)
1944
76.5 mm (3.0 in)
1945
186.2 mm (7.3 in)
1946
71.6 mm (2.8 in)
1947
106.7 mm (4.2 in)
1948
138.8 mm (5.5 in)
1949
89.4 mm (3.5 in)
1950
94.7 mm (3.7 in)
1951
71.1 mm (2.8 in)
1952
83.3 mm (3.3 in)
1953
62.7 mm (2.5 in)
1954
80.8 mm (3.2 in)
1955
116.1 mm (4.6 in)
1956
92.2 mm (3.6 in)
1957
87.7 mm (3.5 in)
1958
111.3 mm (4.4 in)
1959
81.9 mm (3.2 in)
1960
76.2 mm (3.0 in)
1961
75.2 mm (3.0 in)
1962
104.1 mm (4.1 in)
1963
99.1 mm (3.9 in)
1964
156.7 mm (6.2 in)
1965
73.7 mm (2.9 in)
1966
101.3 mm (4.0 in)
1967
65.8 mm (2.6 in)
1968
74.7 mm (2.9 in)
1969
100.1 mm (3.9 in)
1970
100.1 mm (3.9 in)
1971
103.8 mm (4.1 in)
1972
123.7 mm (4.9 in)
1973
93.8 mm (3.7 in)
1974
105.4 mm (4.1 in)
1975
77.7 mm (3.1 in)
1976
70.1 mm (2.8 in)
1977
109.3 mm (4.3 in)
1978
111.7 mm (4.4 in)
1979
106.2 mm (4.2 in)
1980
102.9 mm (4.1 in)
1981
97.1 mm (3.8 in)
1982
97.1 mm (3.8 in)
1983
73.9 mm (2.9 in)
1984
131.5 mm (5.2 in)
1985
71.4 mm (2.8 in)
1986
67.5 mm (2.7 in)
1987
71.5 mm (2.8 in)
1988
59.2 mm (2.3 in)
1989
106.2 mm (4.2 in)
1990
103.7 mm (4.1 in)
1991
117.7 mm (4.6 in)
1992
86.3 mm (3.4 in)
1993
55.4 mm (2.2 in)
Longest dry spell (CDD)
The longest dry spell of the year at Williamson, 1900 to 1993. The record is 32 days in 1903, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Williamson by year
Year
Longest dry spell (CDD)
1900
14 days
1901
20 days
1902
19 days
1903
32 days
1904
17 days
1905
19 days
1906
21 days
1907
13 days
1908
22 days
1909
17 days
1910
22 days
1911
19 days
1912
19 days
1913
15 days
1914
19 days
1915
22 days
1916
16 days
1917
24 days
1918
27 days
1919
13 days
1920
25 days
1921
15 days
1922
24 days
1923
27 days
1924
26 days
1925
19 days
1926
15 days
1927
14 days
1928
12 days
1929
11 days
1930
21 days
1931
22 days
1932
15 days
1933
20 days
1934
12 days
1935
21 days
1936
16 days
1937
10 days
1938
19 days
1939
11 days
1940
21 days
1941
17 days
1942
17 days
1943
19 days
1944
17 days
1945
16 days
1946
13 days
1947
15 days
1948
13 days
1949
15 days
1950
12 days
1951
15 days
1952
23 days
1953
21 days
1954
22 days
1955
15 days
1956
14 days
1957
20 days
1958
22 days
1959
19 days
1960
18 days
1961
14 days
1962
14 days
1963
28 days
1964
24 days
1965
17 days
1966
18 days
1967
16 days
1968
18 days
1969
18 days
1970
16 days
1971
14 days
1972
13 days
1973
19 days
1974
17 days
1975
18 days
1976
19 days
1977
10 days
1978
12 days
1979
11 days
1980
19 days
1981
18 days
1982
13 days
1983
15 days
1984
26 days
1985
15 days
1986
15 days
1987
18 days
1988
23 days
1989
19 days
1990
12 days
1991
24 days
1992
13 days
1993
17 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 Williamson falls on 15 April and the median first autumn frost on 28 October, which leaves a median of 198 days between them.
In 1946 to 1985 the median growing season was 196 days. That is 5 days fewer than in 1901 to 1934.
Fitted over all years, the growing season changes by -0.9 days per decade at this station.
Frost dates and growing season at Williamson
Measure
Median, all years
Earliest period (1901 to 1934)
Recent period (1946 to 1985)
Recent against earliest
Fitted trend
Last spring frost
15 April
13 April
20 April
7 days later
+1.1 days per decade
First autumn frost
28 October
29 October
30 October
1 day later
+0.2 days per decade
Growing days
198 days
201 days
196 days
5 days fewer
-0.9 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
79 years, 1901 to 1990
A day with at least 54.1 mm (2.1 in) of rain is expected about once in 2 years. A day with at least 130.7 mm (5.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Williamson: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
54.1 mm (2.1 in)
5 years
70.6 mm (2.8 in)
10 years
83.0 mm (3.3 in)
25 years
100.5 mm (4.0 in)
50 years
114.9 mm (4.5 in)
100 years
130.7 mm (5.1 in)
Longer than the 79 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, 79 years of values from 1901 to 1990.
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: 117.3 mm (4.6 in) in 1945; 101.6 mm (4.0 in) in 1947; 100.3 mm (3.9 in) in 1971.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Williamson, at 1957. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1957 ran 0.3 C (0.5 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Williamson, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1957
+0.3
+0.5
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 Williamson standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Williamson 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.