Record envelope, standing records and threshold days for Powell (USC00487380), Wyoming, United States, with 75 years of record.
Key Facts for Powell
Powell (USC00487380) is a weather station in Wyoming, United States at 44.75 latitude and -108.77 longitude, 1,336 m (4,383 ft) above sea level.
The station reports from 1907 to 1981, 75 years of record.
1,464 records set at Powell still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Powell set a daily record precipitation of 2.3 mm (0.09 in) on 31 March 1981.
About the Station
Location: Wyoming, United States, 44.75 latitude, -108.77 longitude.
Elevation: 1,336 m (4,383 ft).
Period of record: 1907 to 1981, 75 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 Powell. 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 Powell, 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)
-35.6 C (-32.1 F)
n/a
n/a
Feb
20.6 C (69.1 F)
-37.8 C (-36.0 F)
n/a
n/a
Mar
25.6 C (78.1 F)
-27.8 C (-18.0 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-25.6 C (-14.1 F)
n/a
n/a
May
35.0 C (95.0 F)
-10.0 C (14.0 F)
n/a
n/a
Jun
38.3 C (100.9 F)
-2.2 C (28.0 F)
n/a
n/a
Jul
39.4 C (102.9 F)
2.8 C (37.0 F)
n/a
n/a
Aug
38.9 C (102.0 F)
-3.3 C (26.1 F)
n/a
n/a
Sep
36.7 C (98.1 F)
-11.1 C (12.0 F)
n/a
n/a
Oct
31.1 C (88.0 F)
-18.3 C (-0.9 F)
n/a
n/a
Nov
24.4 C (75.9 F)
-29.4 C (-20.9 F)
n/a
n/a
Dec
20.0 C (68.0 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 Powell still stand. 1918 holds the most, with 47.
Standing records at Powell by the year they were set
Year set
Standing records
1907
24
1908
22
1909
25
1910
31
1911
26
1912
14
1913
17
1914
11
1915
26
1916
38
1917
27
1918
47
1919
33
1920
18
1921
29
1922
19
1923
8
1924
25
1925
17
1926
18
1927
25
1928
18
1929
23
1930
19
1931
34
1932
31
1933
22
1934
22
1935
23
1936
41
1937
22
1938
10
1939
21
1940
14
1941
8
1942
13
1943
17
1944
7
1945
15
1946
10
1947
13
1948
15
1949
20
1950
28
1951
23
1952
12
1953
24
1954
33
1955
15
1956
15
1957
9
1958
16
1959
19
1960
22
1961
13
1962
15
1963
18
1964
13
1965
21
1966
22
1967
12
1968
10
1969
24
1970
16
1971
13
1972
36
1973
9
1974
17
1975
17
1976
12
1977
16
1978
16
1979
15
1980
14
1981
1
All-Time Record Progression
7 new records
7 all-time records were set at Powell between 10 July 1951 and 26 January 1979. Each dot is a new record.
When Powell set new all-time records
Date
Kind
Detail
1951-07-10
Record daily precipitation
Record daily precipitation 37.6 mm (1.5 in)
1959-04-16
Record daily snowfall
Record daily snowfall 25.4 cm (10.0 in)
1965-08-13
Record high minimum temperature
Record high minimum temperature 22.2 C (72.0 F)
1969-06-25
Record daily precipitation
Record daily precipitation 45.0 mm (1.8 in)
1975-01-26
Record daily snowfall
Record daily snowfall 27.9 cm (11.0 in)
1979-01-12
Record snow depth
Record snow depth 43.2 cm (17.0 in)
1979-01-26
Record snow depth
Record snow depth 45.7 cm (18.0 in)
Wettest Day of Each Month
Jun: 45.0 mm (1.8 in)
The wettest day on record for each calendar month at Powell. The most was 45.0 mm (1.8 in) on 25 June 1969.
Record daily precipitation for each month at Powell
Month
Record daily precipitation (mm)
Date
Jan
12.7 mm (0.5 in)
7 January 1909
Feb
20.6 mm (0.8 in)
8 February 1953
Mar
17.3 mm (0.7 in)
6 March 1907
Apr
33.0 mm (1.3 in)
27 April 1963
May
34.5 mm (1.4 in)
10 May 1980
Jun
45.0 mm (1.8 in)
25 June 1969
Jul
37.6 mm (1.5 in)
10 July 1951
Aug
36.3 mm (1.4 in)
20 August 1965
Sep
29.7 mm (1.2 in)
23 September 1918
Oct
23.9 mm (0.9 in)
1 October 1971
Nov
11.4 mm (0.4 in)
7 November 1927
Dec
10.9 mm (0.4 in)
17 December 1929
Period of Record Coverage
1907 to 1981
Complete yearUnder 90 percent of days
75 years of record at Powell, 1907 to 1981. 4 years have data for under 90 percent of days and are left out of rankings: 1907, 1908, 1928, 1981.
Cooler than the station meanWarmer than the station mean
One stripe for each of 67 complete years at Powell, 1909 to 1980. Blue stripes are years cooler than the station's own mean of 7.4 C (45.3 F); red stripes are warmer. The coolest year was 1916, at 4.8 C (40.6 F), and the warmest was 1974, at 9.3 C (48.7 F). The strongest colour marks a difference of 2.7 C (4.9 F).
Annual mean temperature at Powell as warming stripes, 1909 to 1980
Year
Annual mean temperature
Difference from the station mean
1909
6.2 C
-1.17 C
1910
8.0 C
+0.60 C
1911
6.7 C
-0.73 C
1913
6.3 C
-1.12 C
1914
7.2 C
-0.24 C
1915
7.2 C
-0.22 C
1916
4.8 C
-2.65 C
1917
5.6 C
-1.83 C
1918
6.4 C
-1.02 C
1919
6.3 C
-1.15 C
1920
6.2 C
-1.22 C
1921
7.8 C
+0.38 C
1922
5.6 C
-1.81 C
1923
6.5 C
-0.89 C
1924
5.4 C
-1.98 C
1925
7.2 C
-0.26 C
1926
7.1 C
-0.28 C
1927
6.0 C
-1.41 C
1929
5.5 C
-1.95 C
1930
7.3 C
-0.13 C
1931
7.7 C
+0.29 C
1932
6.4 C
-1.06 C
1933
7.5 C
+0.05 C
1934
8.2 C
+0.83 C
1935
6.5 C
-0.96 C
1936
6.5 C
-0.95 C
1937
6.8 C
-0.59 C
1938
7.9 C
+0.45 C
1939
8.3 C
+0.88 C
1940
8.2 C
+0.83 C
1942
7.0 C
-0.39 C
1943
7.8 C
+0.36 C
1944
7.3 C
-0.15 C
1945
7.0 C
-0.42 C
1946
8.0 C
+0.60 C
1947
7.2 C
-0.17 C
1948
7.0 C
-0.43 C
1949
6.8 C
-0.66 C
1950
6.3 C
-1.16 C
1951
5.8 C
-1.61 C
1952
7.8 C
+0.42 C
1953
8.9 C
+1.45 C
1954
8.6 C
+1.19 C
1955
7.5 C
+0.09 C
1956
8.6 C
+1.18 C
1957
7.9 C
+0.51 C
1958
8.8 C
+1.37 C
1959
7.7 C
+0.25 C
1960
8.4 C
+1.02 C
1961
8.5 C
+1.12 C
1962
8.1 C
+0.70 C
1963
8.8 C
+1.36 C
1965
7.9 C
+0.45 C
1966
8.9 C
+1.47 C
1967
8.6 C
+1.21 C
1968
7.8 C
+0.34 C
1969
8.5 C
+1.06 C
1970
8.5 C
+1.05 C
1971
8.3 C
+0.84 C
1972
7.9 C
+0.47 C
1973
8.2 C
+0.76 C
1974
9.3 C
+1.85 C
1976
8.8 C
+1.43 C
1977
8.8 C
+1.41 C
1978
6.7 C
-0.75 C
1979
7.7 C
+0.33 C
1980
7.9 C
+0.52 C
The annual mean temperature here has risen by 0.3 C (0.2 to 0.4) per decade over 1909 to 1980. In Fahrenheit: 0.6 F (0.4 to 0.8) per decade. The slope is a straight line fitted to 67 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Powell
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.3 C (0.2 to 0.4) per decade
0.6 F (0.4 to 0.8) per decade
1909 to 1980
67
Rise
Mean daily maximum
0.3 C (0.1 to 0.4) per decade
0.5 F (0.3 to 0.7) per decade
1909 to 1980
67
Rise
Mean daily minimum
0.4 C (0.3 to 0.5) per decade
0.7 F (0.5 to 0.9) per decade
1909 to 1980
67
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
1907 to 1981
Yearly extremes at Powell: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
39.4 C (102.9 F)
1931
36.7 C (98.1 F)
75
Coldest night (TNn)
-37.8 C (-36.0 F)
1933
-29.4 C (-20.9 F)
75
Wettest day (Rx1day)
45.0 mm (1.8 in)
1969
19.1 mm (0.8 in)
75
Wettest five days (Rx5day)
68.3 mm (2.7 in)
1932
28.2 mm (1.1 in)
75
Longest dry spell (CDD)
158 days
1919
61 days
75
Hottest day (TXx)
The hottest day of the year at Powell, 1907 to 1981. The record is 39.4 C (102.9 F) in 1931, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Powell by year
Year
Hottest day (TXx)
1907
36.1 C (97.0 F)
1908
37.8 C (100.0 F)
1909
37.8 C (100.0 F)
1910
38.3 C (100.9 F)
1911
33.9 C (93.0 F)
1912
34.4 C (93.9 F)
1913
35.6 C (96.1 F)
1914
34.4 C (93.9 F)
1915
35.0 C (95.0 F)
1916
36.1 C (97.0 F)
1917
37.2 C (99.0 F)
1918
36.1 C (97.0 F)
1919
37.2 C (99.0 F)
1920
36.7 C (98.1 F)
1921
37.2 C (99.0 F)
1922
34.4 C (93.9 F)
1923
35.0 C (95.0 F)
1924
35.0 C (95.0 F)
1925
38.3 C (100.9 F)
1926
36.1 C (97.0 F)
1927
35.6 C (96.1 F)
1928
31.1 C (88.0 F)
1929
37.2 C (99.0 F)
1930
38.3 C (100.9 F)
1931
39.4 C (102.9 F)
1932
36.1 C (97.0 F)
1933
37.2 C (99.0 F)
1934
35.6 C (96.1 F)
1935
36.1 C (97.0 F)
1936
36.7 C (98.1 F)
1937
37.8 C (100.0 F)
1938
35.0 C (95.0 F)
1939
38.9 C (102.0 F)
1940
36.7 C (98.1 F)
1941
36.1 C (97.0 F)
1942
35.0 C (95.0 F)
1943
35.6 C (96.1 F)
1944
35.0 C (95.0 F)
1945
36.1 C (97.0 F)
1946
35.0 C (95.0 F)
1947
37.2 C (99.0 F)
1948
36.1 C (97.0 F)
1949
37.2 C (99.0 F)
1950
36.1 C (97.0 F)
1951
35.0 C (95.0 F)
1952
35.0 C (95.0 F)
1953
37.2 C (99.0 F)
1954
37.8 C (100.0 F)
1955
38.3 C (100.9 F)
1956
36.7 C (98.1 F)
1957
36.7 C (98.1 F)
1958
37.8 C (100.0 F)
1959
38.3 C (100.9 F)
1960
37.8 C (100.0 F)
1961
38.9 C (102.0 F)
1962
37.2 C (99.0 F)
1963
36.7 C (98.1 F)
1964
38.9 C (102.0 F)
1965
36.1 C (97.0 F)
1966
38.9 C (102.0 F)
1967
35.6 C (96.1 F)
1968
35.6 C (96.1 F)
1969
36.7 C (98.1 F)
1970
38.3 C (100.9 F)
1971
37.2 C (99.0 F)
1972
35.6 C (96.1 F)
1973
36.7 C (98.1 F)
1974
36.7 C (98.1 F)
1975
37.8 C (100.0 F)
1976
38.3 C (100.9 F)
1977
37.8 C (100.0 F)
1978
36.7 C (98.1 F)
1979
38.3 C (100.9 F)
1980
36.7 C (98.1 F)
1981
19.4 C (66.9 F)
Coldest night (TNn)
The coldest night of the year at Powell, 1907 to 1981. The record is -37.8 C (-36.0 F) in 1933, marked on the chart; the median year is -29.4 C (-20.9 F).
Coldest night (TNn) at Powell by year
Year
Coldest night (TNn)
1907
-26.7 C (-16.1 F)
1908
-29.4 C (-20.9 F)
1909
-35.0 C (-31.0 F)
1910
-33.3 C (-27.9 F)
1911
-30.6 C (-23.1 F)
1912
-27.8 C (-18.0 F)
1913
-30.0 C (-22.0 F)
1914
-32.8 C (-27.0 F)
1915
-25.6 C (-14.1 F)
1916
-33.3 C (-27.9 F)
1917
-32.8 C (-27.0 F)
1918
-33.3 C (-27.9 F)
1919
-35.6 C (-32.1 F)
1920
-26.1 C (-15.0 F)
1921
-24.4 C (-11.9 F)
1922
-30.6 C (-23.1 F)
1923
-33.3 C (-27.9 F)
1924
-35.6 C (-32.1 F)
1925
-22.8 C (-9.0 F)
1926
-28.3 C (-18.9 F)
1927
-31.1 C (-24.0 F)
1928
-31.7 C (-25.1 F)
1929
-35.6 C (-32.1 F)
1930
-35.6 C (-32.1 F)
1931
-23.3 C (-9.9 F)
1932
-34.4 C (-29.9 F)
1933
-37.8 C (-36.0 F)
1934
-25.6 C (-14.1 F)
1935
-32.8 C (-27.0 F)
1936
-37.8 C (-36.0 F)
1937
-32.8 C (-27.0 F)
1938
-26.1 C (-15.0 F)
1939
-32.2 C (-26.0 F)
1940
-27.2 C (-17.0 F)
1941
-17.8 C (0.0 F)
1942
-30.0 C (-22.0 F)
1943
-31.7 C (-25.1 F)
1944
-26.1 C (-15.0 F)
1945
-25.6 C (-14.1 F)
1946
-23.3 C (-9.9 F)
1947
-22.8 C (-9.0 F)
1948
-29.4 C (-20.9 F)
1949
-33.3 C (-27.9 F)
1950
-29.4 C (-20.9 F)
1951
-34.4 C (-29.9 F)
1952
-27.2 C (-17.0 F)
1953
-18.9 C (-2.0 F)
1954
-27.8 C (-18.0 F)
1955
-25.6 C (-14.1 F)
1956
-27.2 C (-17.0 F)
1957
-29.4 C (-20.9 F)
1958
-22.2 C (-8.0 F)
1959
-30.0 C (-22.0 F)
1960
-25.0 C (-13.0 F)
1961
-25.0 C (-13.0 F)
1962
-30.6 C (-23.1 F)
1963
-32.8 C (-27.0 F)
1964
-33.3 C (-27.9 F)
1965
-23.3 C (-9.9 F)
1966
-25.0 C (-13.0 F)
1967
-23.3 C (-9.9 F)
1968
-29.4 C (-20.9 F)
1969
-27.2 C (-17.0 F)
1970
-22.8 C (-9.0 F)
1971
-22.8 C (-9.0 F)
1972
-31.1 C (-24.0 F)
1973
-28.9 C (-20.0 F)
1974
-27.2 C (-17.0 F)
1975
-25.0 C (-13.0 F)
1976
-25.6 C (-14.1 F)
1977
-26.1 C (-15.0 F)
1978
-31.7 C (-25.1 F)
1979
-31.1 C (-24.0 F)
1980
-28.9 C (-20.0 F)
1981
-29.4 C (-20.9 F)
Wettest day (Rx1day)
The wettest day of the year at Powell, 1907 to 1981. The record is 45.0 mm (1.8 in) in 1969, marked on the chart; the median year is 19.1 mm (0.8 in).
Wettest day (Rx1day) at Powell by year
Year
Wettest day (Rx1day)
1907
17.3 mm (0.7 in)
1908
16.0 mm (0.6 in)
1909
20.1 mm (0.8 in)
1910
11.9 mm (0.5 in)
1911
20.8 mm (0.8 in)
1912
25.4 mm (1.0 in)
1913
13.7 mm (0.5 in)
1914
23.4 mm (0.9 in)
1915
27.4 mm (1.1 in)
1916
12.2 mm (0.5 in)
1917
24.6 mm (1.0 in)
1918
29.7 mm (1.2 in)
1919
7.6 mm (0.30 in)
1920
8.9 mm (0.35 in)
1921
19.1 mm (0.8 in)
1922
18.3 mm (0.7 in)
1923
17.8 mm (0.7 in)
1924
12.2 mm (0.5 in)
1925
12.7 mm (0.5 in)
1926
27.9 mm (1.1 in)
1927
21.6 mm (0.9 in)
1928
11.4 mm (0.4 in)
1929
16.5 mm (0.6 in)
1930
24.9 mm (1.0 in)
1931
26.4 mm (1.0 in)
1932
36.6 mm (1.4 in)
1933
13.2 mm (0.5 in)
1934
13.2 mm (0.5 in)
1935
9.7 mm (0.38 in)
1936
13.5 mm (0.5 in)
1937
30.2 mm (1.2 in)
1938
24.1 mm (0.9 in)
1939
30.7 mm (1.2 in)
1940
17.8 mm (0.7 in)
1941
32.0 mm (1.3 in)
1942
21.3 mm (0.8 in)
1943
10.7 mm (0.4 in)
1944
19.1 mm (0.8 in)
1945
16.8 mm (0.7 in)
1946
18.0 mm (0.7 in)
1947
21.3 mm (0.8 in)
1948
17.0 mm (0.7 in)
1949
21.6 mm (0.9 in)
1950
14.0 mm (0.6 in)
1951
37.6 mm (1.5 in)
1952
9.7 mm (0.38 in)
1953
24.6 mm (1.0 in)
1954
23.4 mm (0.9 in)
1955
21.6 mm (0.9 in)
1956
10.4 mm (0.4 in)
1957
23.6 mm (0.9 in)
1958
26.9 mm (1.1 in)
1959
20.6 mm (0.8 in)
1960
14.0 mm (0.6 in)
1961
29.2 mm (1.1 in)
1962
14.0 mm (0.6 in)
1963
33.0 mm (1.3 in)
1964
24.9 mm (1.0 in)
1965
36.3 mm (1.4 in)
1966
10.7 mm (0.4 in)
1967
18.8 mm (0.7 in)
1968
24.1 mm (0.9 in)
1969
45.0 mm (1.8 in)
1970
12.4 mm (0.5 in)
1971
23.9 mm (0.9 in)
1972
18.3 mm (0.7 in)
1973
27.4 mm (1.1 in)
1974
10.7 mm (0.4 in)
1975
30.7 mm (1.2 in)
1976
18.8 mm (0.7 in)
1977
13.0 mm (0.5 in)
1978
19.8 mm (0.8 in)
1979
13.7 mm (0.5 in)
1980
34.5 mm (1.4 in)
1981
4.1 mm (0.16 in)
Wettest five days (Rx5day)
The wettest five days of the year at Powell, 1907 to 1981. The record is 68.3 mm (2.7 in) in 1932, marked on the chart; the median year is 28.2 mm (1.1 in).
Wettest five days (Rx5day) at Powell by year
Year
Wettest five days (Rx5day)
1907
19.1 mm (0.8 in)
1908
30.3 mm (1.2 in)
1909
39.9 mm (1.6 in)
1910
12.5 mm (0.5 in)
1911
23.1 mm (0.9 in)
1912
35.3 mm (1.4 in)
1913
26.1 mm (1.0 in)
1914
35.3 mm (1.4 in)
1915
55.9 mm (2.2 in)
1916
20.1 mm (0.8 in)
1917
31.4 mm (1.2 in)
1918
34.3 mm (1.4 in)
1919
10.2 mm (0.4 in)
1920
9.2 mm (0.36 in)
1921
32.4 mm (1.3 in)
1922
27.5 mm (1.1 in)
1923
28.2 mm (1.1 in)
1924
16.8 mm (0.7 in)
1925
13.0 mm (0.5 in)
1926
40.2 mm (1.6 in)
1927
30.5 mm (1.2 in)
1928
15.6 mm (0.6 in)
1929
35.1 mm (1.4 in)
1930
40.1 mm (1.6 in)
1931
43.2 mm (1.7 in)
1932
68.3 mm (2.7 in)
1933
13.5 mm (0.5 in)
1934
25.9 mm (1.0 in)
1935
13.3 mm (0.5 in)
1936
21.3 mm (0.8 in)
1937
35.0 mm (1.4 in)
1938
35.6 mm (1.4 in)
1939
47.7 mm (1.9 in)
1940
23.5 mm (0.9 in)
1941
40.4 mm (1.6 in)
1942
25.4 mm (1.0 in)
1943
20.4 mm (0.8 in)
1944
27.9 mm (1.1 in)
1945
23.6 mm (0.9 in)
1946
21.8 mm (0.9 in)
1947
22.6 mm (0.9 in)
1948
25.4 mm (1.0 in)
1949
29.7 mm (1.2 in)
1950
17.1 mm (0.7 in)
1951
45.3 mm (1.8 in)
1952
12.7 mm (0.5 in)
1953
29.9 mm (1.2 in)
1954
28.0 mm (1.1 in)
1955
27.1 mm (1.1 in)
1956
14.2 mm (0.6 in)
1957
40.2 mm (1.6 in)
1958
40.6 mm (1.6 in)
1959
22.4 mm (0.9 in)
1960
27.9 mm (1.1 in)
1961
37.8 mm (1.5 in)
1962
33.9 mm (1.3 in)
1963
43.4 mm (1.7 in)
1964
41.1 mm (1.6 in)
1965
43.1 mm (1.7 in)
1966
14.0 mm (0.6 in)
1967
36.6 mm (1.4 in)
1968
38.5 mm (1.5 in)
1969
65.5 mm (2.6 in)
1970
20.7 mm (0.8 in)
1971
31.0 mm (1.2 in)
1972
21.9 mm (0.9 in)
1973
30.8 mm (1.2 in)
1974
18.1 mm (0.7 in)
1975
38.6 mm (1.5 in)
1976
31.5 mm (1.2 in)
1977
26.0 mm (1.0 in)
1978
33.8 mm (1.3 in)
1979
22.3 mm (0.9 in)
1980
41.1 mm (1.6 in)
1981
4.6 mm (0.18 in)
Longest dry spell (CDD)
The longest dry spell of the year at Powell, 1907 to 1981. The record is 158 days in 1919, marked on the chart; the median year is 61 days.
Longest dry spell (CDD) at Powell by year
Year
Longest dry spell (CDD)
1907
46 days
1908
34 days
1909
96 days
1910
80 days
1911
74 days
1912
60 days
1913
75 days
1914
79 days
1915
86 days
1916
36 days
1917
54 days
1918
54 days
1919
158 days
1920
131 days
1921
151 days
1922
63 days
1923
61 days
1924
84 days
1925
64 days
1926
54 days
1927
56 days
1928
25 days
1929
48 days
1930
80 days
1931
51 days
1932
35 days
1933
68 days
1934
58 days
1935
59 days
1936
67 days
1937
37 days
1938
57 days
1939
56 days
1940
45 days
1941
68 days
1942
70 days
1943
84 days
1944
56 days
1945
66 days
1946
52 days
1947
53 days
1948
67 days
1949
50 days
1950
74 days
1951
76 days
1952
75 days
1953
57 days
1954
81 days
1955
66 days
1956
63 days
1957
72 days
1958
61 days
1959
34 days
1960
51 days
1961
71 days
1962
44 days
1963
74 days
1964
50 days
1965
94 days
1966
100 days
1967
37 days
1968
90 days
1969
88 days
1970
46 days
1971
56 days
1972
39 days
1973
69 days
1974
60 days
1975
42 days
1976
66 days
1977
62 days
1978
36 days
1979
57 days
1980
53 days
1981
34 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
67 years with a frost
Across 67 years with a frost, the median last spring frost at Powell falls on 14 May and the median first autumn frost on 23 September, which leaves a median of 132 days between them.
In 1949 to 1980 the median growing season was 144 days. That is 19 days more than in 1909 to 1940.
Fitted over all years, the growing season changes by +4.2 days per decade at this station.
Frost dates and growing season at Powell
Measure
Median, all years
Earliest period (1909 to 1940)
Recent period (1949 to 1980)
Recent against earliest
Fitted trend
Last spring frost
14 May
18 May
11 May
7 days earlier
-2.8 days per decade
First autumn frost
23 September
23 September
23 September
no change
+1.4 days per decade
Growing days
132 days
125 days
144 days
19 days more
+4.2 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
72 years, 1907 to 1980
A day with at least 19.8 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 43.9 mm (1.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Powell: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
19.8 mm (0.8 in)
5 years
27.1 mm (1.1 in)
10 years
31.6 mm (1.2 in)
25 years
36.9 mm (1.5 in)
50 years
40.5 mm (1.6 in)
100 years
43.9 mm (1.7 in)
Longer than the 72 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, 72 years of values from 1907 to 1980.
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: 45.0 mm (1.8 in) in 1969; 37.6 mm (1.5 in) in 1951; 36.6 mm (1.4 in) in 1932.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Powell, at 1916 and 1937. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1916 ran 0.7 C (1.2 F) lower than in the years before (possible change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1937 ran 0.6 C (1.1 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Powell, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1916
-0.7
-1.2
possible
5
1937
+0.6
+1.1
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 Powell standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Powell 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.