Record envelope, standing records and threshold days for Adel (USC00240056), Montana, United States, with 129 years of record.
Key Facts for Adel
Adel (USC00240056) is a weather station in Montana, United States at 47.01 latitude and -111.67 longitude, 1,529 m (5,017 ft) above sea level.
The station reports from 1898 to 2026, 129 years of record.
1,464 records set at Adel still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Adel tied a daily record low minimum temperature of 1.7 C (35.1 F) on 3 August 2026.
About the Station
Location: Montana, United States, 47.01 latitude, -111.67 longitude.
Elevation: 1,529 m (5,017 ft).
Period of record: 1898 to 2026, 129 years.
Eligible elements: tmax, tmin, prcp, snow.
Daily Record Envelope and 2026
8 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 Adel. The lines show the 2026 daily maximum and minimum. 8 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Adel, 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)
-43.3 C (-45.9 F)
13.3 C (55.9 F)
-24.4 C (-11.9 F)
Feb
18.9 C (66.0 F)
-46.1 C (-51.0 F)
16.1 C (61.0 F)
-27.8 C (-18.0 F)
Mar
21.1 C (70.0 F)
-40.0 C (-40.0 F)
18.9 C (66.0 F)
-21.7 C (-7.1 F)
Apr
28.9 C (84.0 F)
-30.0 C (-22.0 F)
23.9 C (75.0 F)
-8.9 C (16.0 F)
May
32.2 C (90.0 F)
-16.7 C (1.9 F)
27.2 C (81.0 F)
-7.8 C (18.0 F)
Jun
37.2 C (99.0 F)
-6.1 C (21.0 F)
23.9 C (75.0 F)
-1.1 C (30.0 F)
Jul
41.1 C (106.0 F)
-3.9 C (25.0 F)
35.0 C (95.0 F)
5.0 C (41.0 F)
Aug
38.3 C (100.9 F)
-5.6 C (21.9 F)
31.1 C (88.0 F)
0.6 C (33.1 F)
Sep
35.6 C (96.1 F)
-20.6 C (-5.1 F)
17.2 C (63.0 F)
1.7 C (35.1 F)
Oct
30.0 C (86.0 F)
-27.8 C (-18.0 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Dec
19.4 C (66.9 F)
-43.3 C (-45.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Adel still stand. 1936 holds the most, with 86.
Standing records at Adel by the year they were set
Year set
Standing records
1898
14
1899
33
1900
22
1901
16
1902
21
1903
11
1904
20
1905
18
1906
28
1907
12
1908
17
1909
19
1910
38
1911
14
1912
8
1913
22
1914
21
1915
16
1916
19
1917
16
1918
22
1919
55
1920
7
1921
35
1922
20
1923
11
1924
23
1925
11
1926
23
1927
30
1928
22
1929
25
1930
10
1931
25
1932
20
1933
8
1934
10
1935
36
1936
86
1937
17
1938
14
1939
33
1940
15
1941
12
1942
11
1943
25
1944
16
1945
20
1946
12
1947
21
1948
7
1949
23
1950
32
1951
23
1952
14
1953
18
1954
10
2013
7
2014
20
2015
18
2016
16
2017
14
2018
12
2019
37
2020
20
2021
33
2022
32
2023
17
2024
14
2025
17
2026
20
All-Time Record Progression
4 new records
4 all-time records were set at Adel between 26 July 1933 and 22 July 1936. Each dot is a new record.
When Adel set new all-time records
Date
Kind
Detail
1933-07-26
Record high maximum temperature
Record high maximum temperature 37.8 C (100.0 F)
1934-06-08
Record daily precipitation
Record daily precipitation 106.7 mm (4.2 in)
1936-02-07
Record low maximum temperature
Record low maximum temperature -34.4 C (-29.9 F)
1936-07-22
Record high maximum temperature
Record high maximum temperature 41.1 C (106.0 F)
Wettest Day of Each Month
Jun: 106.7 mm (4.2 in)
The wettest day on record for each calendar month at Adel. The most was 106.7 mm (4.2 in) on 8 June 1934.
Record daily precipitation for each month at Adel
Month
Record daily precipitation (mm)
Date
Jan
27.9 mm (1.1 in)
25 January 1918
Feb
50.8 mm (2.0 in)
7 February 1923
Mar
48.3 mm (1.9 in)
15 March 1924
Apr
55.9 mm (2.2 in)
26 April 1901
May
76.2 mm (3.0 in)
2 May 1912
Jun
106.7 mm (4.2 in)
8 June 1934
Jul
44.5 mm (1.8 in)
3 July 1903
Aug
50.8 mm (2.0 in)
24 August 1910
Sep
71.6 mm (2.8 in)
7 September 1941
Oct
50.8 mm (2.0 in)
5 October 1913
Nov
30.5 mm (1.2 in)
20 November 1906
Dec
38.1 mm (1.5 in)
19 December 1909
Period of Record Coverage
1898 to 2026
Complete yearUnder 90 percent of days
71 years of record at Adel, 1898 to 2026. 21 years have data for under 90 percent of days and are left out of rankings: 1898, 1900, 1902, 1903, 1905, 1929, 1930, 1931 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 37 complete years at Adel, 1899 to 2025. Blue stripes are years cooler than the station's own mean of 5.1 C (41.3 F); red stripes are warmer. The coolest year was 1927, at 1.6 C (34.9 F), and the warmest was 1939, at 6.8 C (44.2 F). The strongest colour marks a difference of 3.6 C (6.5 F).
Annual mean temperature at Adel as warming stripes, 1899 to 2025
Year
Annual mean temperature
Difference from the station mean
1899
2.7 C
-2.40 C
1906
5.4 C
+0.27 C
1908
5.9 C
+0.78 C
1909
4.3 C
-0.80 C
1912
4.8 C
-0.39 C
1913
4.6 C
-0.56 C
1914
5.9 C
+0.72 C
1915
6.5 C
+1.39 C
1916
3.7 C
-1.42 C
1918
6.0 C
+0.83 C
1919
5.7 C
+0.53 C
1921
5.9 C
+0.76 C
1922
4.3 C
-0.86 C
1923
4.5 C
-0.62 C
1924
4.0 C
-1.16 C
1925
5.3 C
+0.16 C
1926
5.1 C
-0.04 C
1927
1.6 C
-3.52 C
1932
4.8 C
-0.34 C
1935
5.5 C
+0.38 C
1936
6.0 C
+0.85 C
1939
6.8 C
+1.66 C
1940
5.9 C
+0.74 C
1941
6.1 C
+0.98 C
1944
5.1 C
-0.01 C
2014
4.6 C
-0.53 C
2015
6.1 C
+1.00 C
2016
5.9 C
+0.78 C
2017
5.1 C
-0.05 C
2018
4.1 C
-1.01 C
2019
2.7 C
-2.49 C
2020
5.2 C
+0.09 C
2021
5.8 C
+0.69 C
2022
5.1 C
-0.09 C
2023
5.8 C
+0.68 C
2024
6.5 C
+1.39 C
2025
6.8 C
+1.61 C
The fitted trend in annual mean temperature here over 1899 to 2025 is 0.04 C (-0.04 to 0.12) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.2) per decade. The slope is a straight line fitted to 37 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Adel
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.04 C (-0.04 to 0.12) per decade
0.1 F (-0.1 to 0.2) per decade
1899 to 2025
37
Not clearly different from zero
Mean daily maximum
-0.07 C (-0.17 to 0.03) per decade
-0.13 F (-0.31 to 0.05) per decade
1899 to 2025
37
Not clearly different from zero
Mean daily minimum
0.2 C (0.1 to 0.2) per decade
0.3 F (0.1 to 0.4) per decade
1899 to 2025
37
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
1898 to 2026
Yearly extremes at Adel: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.1 C (106.0 F)
1936
33.9 C (93.0 F)
71
Coldest night (TNn)
-46.1 C (-51.0 F)
1905
-36.7 C (-34.1 F)
71
Wettest day (Rx1day)
106.7 mm (4.2 in)
1934
40.8 mm (1.6 in)
72
Wettest five days (Rx5day)
177.1 mm (7.0 in)
1908
61.0 mm (2.4 in)
71
Longest dry spell (CDD)
78 days
1939
31 days
72
Hottest day (TXx)
The hottest day of the year at Adel, 1898 to 2026. The record is 41.1 C (106.0 F) in 1936, marked on the chart; the median year is 33.9 C (93.0 F).
Hottest day (TXx) at Adel by year
Year
Hottest day (TXx)
1898
32.2 C (90.0 F)
1899
32.8 C (91.0 F)
1900
36.1 C (97.0 F)
1901
33.3 C (91.9 F)
1902
30.6 C (87.1 F)
1903
32.8 C (91.0 F)
1904
33.3 C (91.9 F)
1905
32.8 C (91.0 F)
1906
34.4 C (93.9 F)
1907
28.9 C (84.0 F)
1908
33.3 C (91.9 F)
1909
31.7 C (89.1 F)
1910
36.1 C (97.0 F)
1911
30.6 C (87.1 F)
1912
31.7 C (89.1 F)
1913
31.7 C (89.1 F)
1914
32.8 C (91.0 F)
1915
31.1 C (88.0 F)
1916
31.1 C (88.0 F)
1917
33.9 C (93.0 F)
1918
32.8 C (91.0 F)
1919
37.2 C (99.0 F)
1920
32.8 C (91.0 F)
1921
34.4 C (93.9 F)
1922
33.9 C (93.0 F)
1923
30.6 C (87.1 F)
1924
33.3 C (91.9 F)
1925
33.9 C (93.0 F)
1926
32.8 C (91.0 F)
1927
30.0 C (86.0 F)
1928
32.8 C (91.0 F)
1929
35.6 C (96.1 F)
1930
31.7 C (89.1 F)
1931
37.2 C (99.0 F)
1932
33.9 C (93.0 F)
1933
37.8 C (100.0 F)
1934
36.7 C (98.1 F)
1935
36.7 C (98.1 F)
1936
41.1 C (106.0 F)
1937
34.4 C (93.9 F)
1938
32.2 C (90.0 F)
1939
36.1 C (97.0 F)
1940
38.3 C (100.9 F)
1941
33.9 C (93.0 F)
1942
35.0 C (95.0 F)
1943
33.9 C (93.0 F)
1944
31.1 C (88.0 F)
1945
34.4 C (93.9 F)
1946
35.0 C (95.0 F)
1947
33.9 C (93.0 F)
1948
34.4 C (93.9 F)
1949
36.1 C (97.0 F)
1950
35.6 C (96.1 F)
1951
36.7 C (98.1 F)
1952
35.0 C (95.0 F)
1953
36.1 C (97.0 F)
1954
33.9 C (93.0 F)
1969
n/a
2013
33.3 C (91.9 F)
2014
33.3 C (91.9 F)
2015
33.3 C (91.9 F)
2016
33.3 C (91.9 F)
2017
33.9 C (93.0 F)
2018
35.6 C (96.1 F)
2019
31.7 C (89.1 F)
2020
31.7 C (89.1 F)
2021
35.6 C (96.1 F)
2022
34.4 C (93.9 F)
2023
33.3 C (91.9 F)
2024
34.4 C (93.9 F)
2025
33.3 C (91.9 F)
2026
35.0 C (95.0 F)
Coldest night (TNn)
The coldest night of the year at Adel, 1898 to 2026. The record is -46.1 C (-51.0 F) in 1905, marked on the chart; the median year is -36.7 C (-34.1 F).
Coldest night (TNn) at Adel by year
Year
Coldest night (TNn)
1898
-38.3 C (-36.9 F)
1899
-45.6 C (-50.1 F)
1900
-41.7 C (-43.1 F)
1901
-32.8 C (-27.0 F)
1902
-38.3 C (-36.9 F)
1903
-38.3 C (-36.9 F)
1904
-36.7 C (-34.1 F)
1905
-46.1 C (-51.0 F)
1906
-39.4 C (-38.9 F)
1907
-35.6 C (-32.1 F)
1908
-24.4 C (-11.9 F)
1909
-38.3 C (-36.9 F)
1910
-37.2 C (-35.0 F)
1911
-38.3 C (-36.9 F)
1912
-33.9 C (-29.0 F)
1913
-32.2 C (-26.0 F)
1914
-33.3 C (-27.9 F)
1915
-26.1 C (-15.0 F)
1916
-42.2 C (-44.0 F)
1917
-33.9 C (-29.0 F)
1918
-34.4 C (-29.9 F)
1919
-37.2 C (-35.0 F)
1920
-32.2 C (-26.0 F)
1921
-34.4 C (-29.9 F)
1922
-37.2 C (-35.0 F)
1923
-40.0 C (-40.0 F)
1924
-41.1 C (-42.0 F)
1925
-27.2 C (-17.0 F)
1926
-36.7 C (-34.1 F)
1927
-43.3 C (-45.9 F)
1928
-34.4 C (-29.9 F)
1929
-42.8 C (-45.0 F)
1930
-41.7 C (-43.1 F)
1931
-30.0 C (-22.0 F)
1932
-39.4 C (-38.9 F)
1933
-38.9 C (-38.0 F)
1934
-32.2 C (-26.0 F)
1935
-38.9 C (-38.0 F)
1936
-45.6 C (-50.1 F)
1937
-37.2 C (-35.0 F)
1938
-35.6 C (-32.1 F)
1939
-40.6 C (-41.1 F)
1940
-35.0 C (-31.0 F)
1941
-31.7 C (-25.1 F)
1942
-35.0 C (-31.0 F)
1943
-41.1 C (-42.0 F)
1944
-30.0 C (-22.0 F)
1945
-36.7 C (-34.1 F)
1946
-32.8 C (-27.0 F)
1947
-35.0 C (-31.0 F)
1948
-35.6 C (-32.1 F)
1949
-42.2 C (-44.0 F)
1950
-41.1 C (-42.0 F)
1951
-40.0 C (-40.0 F)
1952
-34.4 C (-29.9 F)
1953
-28.9 C (-20.0 F)
1954
-43.3 C (-45.9 F)
1969
n/a
2013
-35.0 C (-31.0 F)
2014
-36.7 C (-34.1 F)
2015
-26.7 C (-16.1 F)
2016
-35.0 C (-31.0 F)
2017
-28.3 C (-18.9 F)
2018
-30.6 C (-23.1 F)
2019
-38.9 C (-38.0 F)
2020
-29.4 C (-20.9 F)
2021
-37.2 C (-35.0 F)
2022
-38.3 C (-36.9 F)
2023
-33.9 C (-29.0 F)
2024
-42.8 C (-45.0 F)
2025
-31.7 C (-25.1 F)
2026
-27.8 C (-18.0 F)
Wettest day (Rx1day)
The wettest day of the year at Adel, 1898 to 2026. The record is 106.7 mm (4.2 in) in 1934, marked on the chart; the median year is 40.8 mm (1.6 in).
Wettest day (Rx1day) at Adel by year
Year
Wettest day (Rx1day)
1898
54.6 mm (2.1 in)
1899
48.3 mm (1.9 in)
1900
74.4 mm (2.9 in)
1901
55.9 mm (2.2 in)
1902
36.8 mm (1.4 in)
1903
44.5 mm (1.8 in)
1904
29.0 mm (1.1 in)
1905
40.9 mm (1.6 in)
1906
33.0 mm (1.3 in)
1907
94.0 mm (3.7 in)
1908
88.9 mm (3.5 in)
1909
68.6 mm (2.7 in)
1910
50.8 mm (2.0 in)
1911
45.7 mm (1.8 in)
1912
76.2 mm (3.0 in)
1913
50.8 mm (2.0 in)
1914
43.7 mm (1.7 in)
1915
90.2 mm (3.6 in)
1916
52.1 mm (2.1 in)
1917
33.0 mm (1.3 in)
1918
46.7 mm (1.8 in)
1919
19.1 mm (0.8 in)
1920
28.4 mm (1.1 in)
1921
27.9 mm (1.1 in)
1922
40.6 mm (1.6 in)
1923
50.8 mm (2.0 in)
1924
48.3 mm (1.9 in)
1925
40.6 mm (1.6 in)
1926
47.0 mm (1.9 in)
1927
49.5 mm (1.9 in)
1928
55.9 mm (2.2 in)
1929
30.5 mm (1.2 in)
1930
20.3 mm (0.8 in)
1931
21.6 mm (0.9 in)
1932
63.5 mm (2.5 in)
1933
48.3 mm (1.9 in)
1934
106.7 mm (4.2 in)
1935
22.9 mm (0.9 in)
1936
33.0 mm (1.3 in)
1937
22.1 mm (0.9 in)
1938
50.8 mm (2.0 in)
1939
17.0 mm (0.7 in)
1940
31.8 mm (1.3 in)
1941
71.6 mm (2.8 in)
1942
43.2 mm (1.7 in)
1943
50.8 mm (2.0 in)
1944
38.1 mm (1.5 in)
1945
28.7 mm (1.1 in)
1946
45.7 mm (1.8 in)
1947
36.1 mm (1.4 in)
1948
39.4 mm (1.6 in)
1949
76.7 mm (3.0 in)
1950
23.9 mm (0.9 in)
1951
45.7 mm (1.8 in)
1952
17.0 mm (0.7 in)
1953
60.7 mm (2.4 in)
1954
18.3 mm (0.7 in)
1969
0.0 mm (0.00 in)
2013
50.0 mm (2.0 in)
2014
47.5 mm (1.9 in)
2015
23.6 mm (0.9 in)
2016
20.8 mm (0.8 in)
2017
30.2 mm (1.2 in)
2018
25.4 mm (1.0 in)
2019
24.1 mm (0.9 in)
2020
19.6 mm (0.8 in)
2021
29.5 mm (1.2 in)
2022
39.4 mm (1.6 in)
2023
25.4 mm (1.0 in)
2024
37.8 mm (1.5 in)
2025
38.1 mm (1.5 in)
2026
52.1 mm (2.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Adel, 1898 to 2026. The record is 177.1 mm (7.0 in) in 1908, marked on the chart; the median year is 61.0 mm (2.4 in).
Wettest five days (Rx5day) at Adel by year
Year
Wettest five days (Rx5day)
1898
95.3 mm (3.8 in)
1899
61.0 mm (2.4 in)
1900
76.9 mm (3.0 in)
1901
61.0 mm (2.4 in)
1902
53.3 mm (2.1 in)
1903
47.3 mm (1.9 in)
1904
37.4 mm (1.5 in)
1905
46.2 mm (1.8 in)
1906
50.0 mm (2.0 in)
1907
119.5 mm (4.7 in)
1908
177.1 mm (7.0 in)
1909
109.1 mm (4.3 in)
1910
55.9 mm (2.2 in)
1911
64.7 mm (2.5 in)
1912
80.0 mm (3.1 in)
1913
66.1 mm (2.6 in)
1914
108.5 mm (4.3 in)
1915
171.0 mm (6.7 in)
1916
107.5 mm (4.2 in)
1917
57.7 mm (2.3 in)
1918
61.0 mm (2.4 in)
1919
31.6 mm (1.2 in)
1920
72.8 mm (2.9 in)
1921
73.8 mm (2.9 in)
1922
61.2 mm (2.4 in)
1923
100.3 mm (3.9 in)
1924
82.5 mm (3.2 in)
1925
63.8 mm (2.5 in)
1926
113.1 mm (4.5 in)
1927
89.2 mm (3.5 in)
1928
147.3 mm (5.8 in)
1929
50.8 mm (2.0 in)
1930
59.7 mm (2.4 in)
1931
37.3 mm (1.5 in)
1932
152.4 mm (6.0 in)
1933
48.3 mm (1.9 in)
1934
106.7 mm (4.2 in)
1935
22.9 mm (0.9 in)
1936
33.0 mm (1.3 in)
1937
35.1 mm (1.4 in)
1938
95.2 mm (3.7 in)
1939
35.7 mm (1.4 in)
1940
49.3 mm (1.9 in)
1941
74.9 mm (2.9 in)
1942
56.4 mm (2.2 in)
1943
73.9 mm (2.9 in)
1944
79.9 mm (3.1 in)
1945
55.9 mm (2.2 in)
1946
68.1 mm (2.7 in)
1947
69.1 mm (2.7 in)
1948
66.3 mm (2.6 in)
1949
85.6 mm (3.4 in)
1950
31.7 mm (1.2 in)
1951
60.1 mm (2.4 in)
1952
31.0 mm (1.2 in)
1953
105.5 mm (4.2 in)
1954
47.5 mm (1.9 in)
1969
n/a
2013
62.2 mm (2.4 in)
2014
71.3 mm (2.8 in)
2015
41.4 mm (1.6 in)
2016
31.2 mm (1.2 in)
2017
50.7 mm (2.0 in)
2018
36.0 mm (1.4 in)
2019
24.1 mm (0.9 in)
2020
33.3 mm (1.3 in)
2021
53.9 mm (2.1 in)
2022
51.4 mm (2.0 in)
2023
56.4 mm (2.2 in)
2024
46.7 mm (1.8 in)
2025
38.1 mm (1.5 in)
2026
77.7 mm (3.1 in)
Longest dry spell (CDD)
The longest dry spell of the year at Adel, 1898 to 2026. The record is 78 days in 1939, marked on the chart; the median year is 31 days.
Longest dry spell (CDD) at Adel by year
Year
Longest dry spell (CDD)
1898
26 days
1899
26 days
1900
26 days
1901
32 days
1902
39 days
1903
22 days
1904
41 days
1905
33 days
1906
26 days
1907
61 days
1908
23 days
1909
29 days
1910
32 days
1911
14 days
1912
18 days
1913
35 days
1914
35 days
1915
31 days
1916
21 days
1917
32 days
1918
22 days
1919
28 days
1920
38 days
1921
39 days
1922
25 days
1923
24 days
1924
15 days
1925
19 days
1926
17 days
1927
20 days
1928
29 days
1929
27 days
1930
49 days
1931
45 days
1932
34 days
1933
56 days
1934
38 days
1935
62 days
1936
32 days
1937
58 days
1938
39 days
1939
78 days
1940
33 days
1941
42 days
1942
36 days
1943
26 days
1944
34 days
1945
31 days
1946
27 days
1947
31 days
1948
31 days
1949
40 days
1950
39 days
1951
29 days
1952
25 days
1953
48 days
1954
23 days
1969
1 day
2013
23 days
2014
16 days
2015
29 days
2016
41 days
2017
30 days
2018
25 days
2019
28 days
2020
40 days
2021
45 days
2022
27 days
2023
67 days
2024
35 days
2025
41 days
2026
25 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
37 years with a frost
Across 37 years with a frost, the median last spring frost at Adel falls on 13 June and the median first autumn frost on 23 August, which leaves a median of 74 days between them.
Fitted over all years, the growing season changes by +2.3 days per decade at this station.
Frost dates and growing season at Adel
Measure
Median, all years
Earliest period
Recent period (1915 to 2025)
Recent against earliest
Fitted trend
Last spring frost
13 June
n/a
14 June
n/a
-0.2 days per decade
First autumn frost
23 August
n/a
22 August
n/a
+2.0 days per decade
Growing days
74 days
n/a
73 days
n/a
+2.3 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
55 years, 1899 to 2025
A day with at least 39.8 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 100.8 mm (4.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Adel: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
39.8 mm (1.6 in)
5 years
56.3 mm (2.2 in)
10 years
67.1 mm (2.6 in)
25 years
80.8 mm (3.2 in)
50 years
90.8 mm (3.6 in)
100 years
100.8 mm (4.0 in)
Longer than the 55 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, 55 years of values from 1899 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: 94.0 mm (3.7 in) in 1907; 90.2 mm (3.6 in) in 1915; 88.9 mm (3.5 in) in 1908.
Download the Data
Data for Adel standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Adel 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.