Record envelope, standing records and threshold days for Riverdale (USC00427318), Utah, United States, with 78 years of record.
Key Facts for Riverdale
Riverdale (USC00427318) is a weather station in Utah, United States at 41.15 latitude and -112.00 longitude, 1,341 m (4,400 ft) above sea level.
The station reports from 1914 to 1991, 78 years of record.
1,464 records set at Riverdale still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Riverdale set a daily record precipitation of 7.6 mm (0.30 in) on 28 February 1991.
About the Station
Location: Utah, United States, 41.15 latitude, -112.00 longitude.
Elevation: 1,341 m (4,400 ft).
Period of record: 1914 to 1991, 78 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 Riverdale. 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 Riverdale, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
15.6 C (60.1 F)
-30.6 C (-23.1 F)
n/a
n/a
Feb
20.0 C (68.0 F)
-31.7 C (-25.1 F)
n/a
n/a
Mar
25.0 C (77.0 F)
-15.6 C (3.9 F)
n/a
n/a
Apr
29.4 C (84.9 F)
-15.0 C (5.0 F)
n/a
n/a
May
35.6 C (96.1 F)
-7.8 C (18.0 F)
n/a
n/a
Jun
41.1 C (106.0 F)
-3.9 C (25.0 F)
n/a
n/a
Jul
40.0 C (104.0 F)
4.4 C (39.9 F)
n/a
n/a
Aug
38.9 C (102.0 F)
1.1 C (34.0 F)
n/a
n/a
Sep
36.7 C (98.1 F)
-5.6 C (21.9 F)
n/a
n/a
Oct
31.7 C (89.1 F)
-11.1 C (12.0 F)
n/a
n/a
Nov
26.7 C (80.1 F)
-23.3 C (-9.9 F)
n/a
n/a
Dec
18.9 C (66.0 F)
-27.8 C (-18.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Riverdale still stand. 1914 holds the most, with 55.
Standing records at Riverdale by the year they were set
Year set
Standing records
1914
55
1915
20
1916
22
1917
43
1918
39
1919
47
1920
24
1921
26
1922
18
1923
12
1924
13
1925
11
1926
17
1927
23
1928
14
1929
29
1930
32
1931
19
1932
35
1933
31
1934
17
1935
7
1936
17
1937
23
1938
10
1939
23
1940
20
1941
9
1942
25
1943
25
1944
7
1945
18
1946
15
1947
13
1948
12
1949
27
1950
17
1951
9
1952
17
1953
23
1954
14
1955
26
1956
9
1957
12
1958
29
1959
12
1960
25
1961
10
1962
21
1963
22
1964
24
1965
16
1966
16
1967
15
1968
10
1969
19
1970
18
1971
23
1972
21
1973
8
1974
10
1975
17
1976
6
1977
17
1978
20
1979
16
1980
10
1981
6
1982
11
1983
12
1984
8
1985
21
1986
20
1987
15
1988
12
1989
16
1990
32
1991
1
All-Time Record Progression
1 new records
1 all-time records were set at Riverdale between 23 December 1990 and 23 December 1990. Each dot is a new record.
When Riverdale set new all-time records
Date
Kind
Detail
1990-12-23
Record low maximum temperature
Record low maximum temperature -18.9 C (-2.0 F)
Wettest Day of Each Month
Aug: 62.7 mm (2.5 in)
The wettest day on record for each calendar month at Riverdale. The most was 62.7 mm (2.5 in) on 12 August 1930.
Record daily precipitation for each month at Riverdale
Month
Record daily precipitation (mm)
Date
Jan
50.8 mm (2.0 in)
28 January 1914
Feb
34.3 mm (1.4 in)
16 February 1969
Mar
48.0 mm (1.9 in)
23 March 1949
Apr
55.4 mm (2.2 in)
23 April 1957
May
47.0 mm (1.9 in)
5 May 1926
Jun
45.2 mm (1.8 in)
24 June 1952
Jul
33.0 mm (1.3 in)
21 July 1984
Aug
62.7 mm (2.5 in)
12 August 1930
Sep
50.8 mm (2.0 in)
18 September 1978
Oct
53.3 mm (2.1 in)
3 October 1976
Nov
35.6 mm (1.4 in)
12 November 1954
Dec
30.5 mm (1.2 in)
4 December 1983
Period of Record Coverage
1914 to 1991
Complete yearUnder 90 percent of days
78 years of record at Riverdale, 1914 to 1991. 10 years have data for under 90 percent of days and are left out of rankings: 1916, 1917, 1918, 1944, 1975, 1976, 1979, 1982 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 61 complete years at Riverdale, 1915 to 1990. Blue stripes are years cooler than the station's own mean of 10.3 C (50.5 F); red stripes are warmer. The coolest year was 1932, at 8.0 C (46.3 F), and the warmest was 1958, at 11.7 C (53.1 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Riverdale as warming stripes, 1915 to 1990
Year
Annual mean temperature
Difference from the station mean
1915
10.6 C
+0.32 C
1919
11.3 C
+1.05 C
1920
9.8 C
-0.42 C
1921
11.7 C
+1.41 C
1922
9.6 C
-0.69 C
1923
9.3 C
-0.99 C
1926
11.4 C
+1.11 C
1928
9.7 C
-0.57 C
1929
8.7 C
-1.55 C
1930
8.8 C
-1.43 C
1931
8.8 C
-1.48 C
1932
8.0 C
-2.29 C
1933
9.2 C
-1.02 C
1934
11.7 C
+1.44 C
1936
10.3 C
+0.05 C
1937
10.0 C
-0.26 C
1938
10.7 C
+0.42 C
1939
10.5 C
+0.24 C
1940
11.6 C
+1.35 C
1942
8.8 C
-1.48 C
1943
10.4 C
+0.13 C
1945
10.0 C
-0.29 C
1946
10.7 C
+0.40 C
1947
10.3 C
+0.08 C
1948
9.8 C
-0.45 C
1949
9.7 C
-0.60 C
1950
10.5 C
+0.23 C
1951
9.5 C
-0.78 C
1952
10.1 C
-0.20 C
1953
11.1 C
+0.85 C
1954
11.4 C
+1.15 C
1955
9.7 C
-0.54 C
1956
10.8 C
+0.57 C
1957
10.6 C
+0.36 C
1958
11.7 C
+1.48 C
1959
10.9 C
+0.68 C
1960
11.0 C
+0.72 C
1961
10.7 C
+0.48 C
1962
10.3 C
+0.04 C
1963
10.7 C
+0.42 C
1966
11.2 C
+0.96 C
1967
11.1 C
+0.83 C
1968
10.2 C
-0.03 C
1969
11.1 C
+0.83 C
1970
10.5 C
+0.25 C
1971
9.9 C
-0.34 C
1972
10.5 C
+0.28 C
1973
10.1 C
-0.12 C
1974
11.0 C
+0.77 C
1977
10.3 C
+0.03 C
1978
9.7 C
-0.58 C
1979
9.4 C
-0.90 C
1980
9.8 C
-0.42 C
1981
10.8 C
+0.57 C
1984
8.6 C
-1.68 C
1985
8.7 C
-1.54 C
1986
10.7 C
+0.46 C
1987
10.7 C
+0.42 C
1988
10.3 C
+0.03 C
1989
10.2 C
-0.02 C
1990
10.7 C
+0.47 C
The fitted trend in annual mean temperature here over 1915 to 1990 is 0.03 C (-0.07 to 0.14) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.3) per decade. The slope is a straight line fitted to 61 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Riverdale
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.03 C (-0.07 to 0.14) per decade
0.1 F (-0.1 to 0.3) per decade
1915 to 1990
61
Not clearly different from zero
Mean daily maximum
-0.01 C (-0.13 to 0.12) per decade
-0.01 F (-0.23 to 0.21) per decade
1915 to 1990
61
Not clearly different from zero
Mean daily minimum
0.08 C (-0.04 to 0.19) per decade
0.1 F (-0.1 to 0.3) per decade
1915 to 1990
61
Not clearly different from zero
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
1914 to 1991
Yearly extremes at Riverdale: 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)
1918
37.2 C (99.0 F)
78
Coldest night (TNn)
-31.7 C (-25.1 F)
1933
-19.1 C (-2.5 F)
78
Wettest day (Rx1day)
62.7 mm (2.5 in)
1930
33.2 mm (1.3 in)
78
Wettest five days (Rx5day)
101.1 mm (4.0 in)
1982
56.8 mm (2.2 in)
78
Longest dry spell (CDD)
94 days
1944
39 days
78
Hottest day (TXx)
The hottest day of the year at Riverdale, 1914 to 1991. The record is 41.1 C (106.0 F) in 1918, marked on the chart; the median year is 37.2 C (99.0 F).
Hottest day (TXx) at Riverdale by year
Year
Hottest day (TXx)
1914
35.6 C (96.1 F)
1915
36.1 C (97.0 F)
1916
38.3 C (100.9 F)
1917
39.4 C (102.9 F)
1918
41.1 C (106.0 F)
1919
40.6 C (105.1 F)
1920
36.1 C (97.0 F)
1921
36.7 C (98.1 F)
1922
36.7 C (98.1 F)
1923
38.9 C (102.0 F)
1924
36.7 C (98.1 F)
1925
38.9 C (102.0 F)
1926
38.9 C (102.0 F)
1927
36.1 C (97.0 F)
1928
36.7 C (98.1 F)
1929
38.3 C (100.9 F)
1930
40.0 C (104.0 F)
1931
38.9 C (102.0 F)
1932
35.0 C (95.0 F)
1933
37.2 C (99.0 F)
1934
36.1 C (97.0 F)
1935
36.7 C (98.1 F)
1936
37.2 C (99.0 F)
1937
37.8 C (100.0 F)
1938
36.7 C (98.1 F)
1939
38.3 C (100.9 F)
1940
37.8 C (100.0 F)
1941
36.1 C (97.0 F)
1942
36.1 C (97.0 F)
1943
38.9 C (102.0 F)
1944
35.0 C (95.0 F)
1945
36.7 C (98.1 F)
1946
36.1 C (97.0 F)
1947
37.8 C (100.0 F)
1948
36.1 C (97.0 F)
1949
37.2 C (99.0 F)
1950
36.1 C (97.0 F)
1951
36.1 C (97.0 F)
1952
35.0 C (95.0 F)
1953
36.1 C (97.0 F)
1954
37.8 C (100.0 F)
1955
38.9 C (102.0 F)
1956
37.8 C (100.0 F)
1957
36.7 C (98.1 F)
1958
37.2 C (99.0 F)
1959
37.8 C (100.0 F)
1960
40.0 C (104.0 F)
1961
36.1 C (97.0 F)
1962
36.1 C (97.0 F)
1963
36.7 C (98.1 F)
1964
36.7 C (98.1 F)
1965
36.7 C (98.1 F)
1966
37.8 C (100.0 F)
1967
38.3 C (100.9 F)
1968
37.8 C (100.0 F)
1969
37.8 C (100.0 F)
1970
38.3 C (100.9 F)
1971
37.8 C (100.0 F)
1972
37.8 C (100.0 F)
1973
37.8 C (100.0 F)
1974
37.8 C (100.0 F)
1975
36.7 C (98.1 F)
1976
37.2 C (99.0 F)
1977
37.8 C (100.0 F)
1978
39.4 C (102.9 F)
1979
38.3 C (100.9 F)
1980
37.2 C (99.0 F)
1981
38.3 C (100.9 F)
1982
37.2 C (99.0 F)
1983
37.2 C (99.0 F)
1984
34.4 C (93.9 F)
1985
36.7 C (98.1 F)
1986
36.1 C (97.0 F)
1987
35.6 C (96.1 F)
1988
36.7 C (98.1 F)
1989
38.3 C (100.9 F)
1990
38.3 C (100.9 F)
1991
17.8 C (64.0 F)
Coldest night (TNn)
The coldest night of the year at Riverdale, 1914 to 1991. The record is -31.7 C (-25.1 F) in 1933, marked on the chart; the median year is -19.1 C (-2.5 F).
Coldest night (TNn) at Riverdale by year
Year
Coldest night (TNn)
1914
-17.2 C (1.0 F)
1915
-18.9 C (-2.0 F)
1916
-17.8 C (0.0 F)
1917
-22.8 C (-9.0 F)
1918
-17.8 C (0.0 F)
1919
-24.4 C (-11.9 F)
1920
-15.6 C (3.9 F)
1921
-16.7 C (1.9 F)
1922
-23.9 C (-11.0 F)
1923
-20.0 C (-4.0 F)
1924
-26.7 C (-16.1 F)
1925
-16.7 C (1.9 F)
1926
-19.4 C (-2.9 F)
1927
-18.9 C (-2.0 F)
1928
-18.3 C (-0.9 F)
1929
-27.8 C (-18.0 F)
1930
-27.2 C (-17.0 F)
1931
-21.7 C (-7.1 F)
1932
-25.6 C (-14.1 F)
1933
-31.7 C (-25.1 F)
1934
-16.7 C (1.9 F)
1935
-19.4 C (-2.9 F)
1936
-25.0 C (-13.0 F)
1937
-30.6 C (-23.1 F)
1938
-12.8 C (9.0 F)
1939
-18.3 C (-0.9 F)
1940
-15.0 C (5.0 F)
1941
-13.3 C (8.1 F)
1942
-22.8 C (-9.0 F)
1943
-20.0 C (-4.0 F)
1944
-20.0 C (-4.0 F)
1945
-15.6 C (3.9 F)
1946
-14.4 C (6.1 F)
1947
-20.6 C (-5.1 F)
1948
-19.4 C (-2.9 F)
1949
-22.2 C (-8.0 F)
1950
-20.0 C (-4.0 F)
1951
-18.9 C (-2.0 F)
1952
-18.9 C (-2.0 F)
1953
-12.8 C (9.0 F)
1954
-13.3 C (8.1 F)
1955
-23.3 C (-9.9 F)
1956
-19.4 C (-2.9 F)
1957
-16.7 C (1.9 F)
1958
-12.8 C (9.0 F)
1959
-20.0 C (-4.0 F)
1960
-17.8 C (0.0 F)
1961
-17.8 C (0.0 F)
1962
-20.6 C (-5.1 F)
1963
-24.4 C (-11.9 F)
1964
-18.9 C (-2.0 F)
1965
-13.3 C (8.1 F)
1966
-15.6 C (3.9 F)
1967
-15.0 C (5.0 F)
1968
-17.8 C (0.0 F)
1969
-15.0 C (5.0 F)
1970
-17.8 C (0.0 F)
1971
-21.7 C (-7.1 F)
1972
-25.6 C (-14.1 F)
1973
-20.0 C (-4.0 F)
1974
-20.0 C (-4.0 F)
1975
-21.7 C (-7.1 F)
1976
-17.8 C (0.0 F)
1977
-20.6 C (-5.1 F)
1978
-20.6 C (-5.1 F)
1979
-24.4 C (-11.9 F)
1980
-18.9 C (-2.0 F)
1981
-17.8 C (0.0 F)
1982
-23.3 C (-9.9 F)
1983
-18.3 C (-0.9 F)
1984
-21.7 C (-7.1 F)
1985
-24.4 C (-11.9 F)
1986
-12.8 C (9.0 F)
1987
-16.1 C (3.0 F)
1988
-18.9 C (-2.0 F)
1989
-22.8 C (-9.0 F)
1990
-27.8 C (-18.0 F)
1991
-18.9 C (-2.0 F)
Wettest day (Rx1day)
The wettest day of the year at Riverdale, 1914 to 1991. The record is 62.7 mm (2.5 in) in 1930, marked on the chart; the median year is 33.2 mm (1.3 in).
Wettest day (Rx1day) at Riverdale by year
Year
Wettest day (Rx1day)
1914
50.8 mm (2.0 in)
1915
33.8 mm (1.3 in)
1916
42.4 mm (1.7 in)
1917
23.4 mm (0.9 in)
1918
14.0 mm (0.6 in)
1919
26.2 mm (1.0 in)
1920
19.3 mm (0.8 in)
1921
33.0 mm (1.3 in)
1922
27.7 mm (1.1 in)
1923
26.4 mm (1.0 in)
1924
27.9 mm (1.1 in)
1925
34.5 mm (1.4 in)
1926
47.0 mm (1.9 in)
1927
22.9 mm (0.9 in)
1928
20.3 mm (0.8 in)
1929
38.6 mm (1.5 in)
1930
62.7 mm (2.5 in)
1931
25.4 mm (1.0 in)
1932
45.7 mm (1.8 in)
1933
25.4 mm (1.0 in)
1934
33.0 mm (1.3 in)
1935
28.4 mm (1.1 in)
1936
33.8 mm (1.3 in)
1937
32.8 mm (1.3 in)
1938
38.6 mm (1.5 in)
1939
33.8 mm (1.3 in)
1940
26.7 mm (1.1 in)
1941
30.0 mm (1.2 in)
1942
30.5 mm (1.2 in)
1943
38.1 mm (1.5 in)
1944
33.3 mm (1.3 in)
1945
27.2 mm (1.1 in)
1946
45.2 mm (1.8 in)
1947
45.7 mm (1.8 in)
1948
24.4 mm (1.0 in)
1949
48.0 mm (1.9 in)
1950
26.2 mm (1.0 in)
1951
62.0 mm (2.4 in)
1952
45.2 mm (1.8 in)
1953
40.6 mm (1.6 in)
1954
35.6 mm (1.4 in)
1955
25.7 mm (1.0 in)
1956
26.2 mm (1.0 in)
1957
55.4 mm (2.2 in)
1958
18.0 mm (0.7 in)
1959
27.9 mm (1.1 in)
1960
19.6 mm (0.8 in)
1961
38.1 mm (1.5 in)
1962
30.5 mm (1.2 in)
1963
28.4 mm (1.1 in)
1964
39.1 mm (1.5 in)
1965
33.0 mm (1.3 in)
1966
34.8 mm (1.4 in)
1967
24.9 mm (1.0 in)
1968
37.6 mm (1.5 in)
1969
34.3 mm (1.4 in)
1970
48.5 mm (1.9 in)
1971
39.1 mm (1.5 in)
1972
29.7 mm (1.2 in)
1973
36.6 mm (1.4 in)
1974
36.6 mm (1.4 in)
1975
43.4 mm (1.7 in)
1976
53.3 mm (2.1 in)
1977
33.0 mm (1.3 in)
1978
50.8 mm (2.0 in)
1979
46.7 mm (1.8 in)
1980
31.8 mm (1.3 in)
1981
36.1 mm (1.4 in)
1982
36.3 mm (1.4 in)
1983
31.5 mm (1.2 in)
1984
33.0 mm (1.3 in)
1985
46.2 mm (1.8 in)
1986
46.0 mm (1.8 in)
1987
22.9 mm (0.9 in)
1988
25.9 mm (1.0 in)
1989
37.3 mm (1.5 in)
1990
23.1 mm (0.9 in)
1991
30.7 mm (1.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Riverdale, 1914 to 1991. The record is 101.1 mm (4.0 in) in 1982, marked on the chart; the median year is 56.8 mm (2.2 in).
Wettest five days (Rx5day) at Riverdale by year
Year
Wettest five days (Rx5day)
1914
88.4 mm (3.5 in)
1915
35.0 mm (1.4 in)
1916
80.5 mm (3.2 in)
1917
46.3 mm (1.8 in)
1918
19.8 mm (0.8 in)
1919
25.2 mm (1.0 in)
1920
36.3 mm (1.4 in)
1921
64.1 mm (2.5 in)
1922
32.8 mm (1.3 in)
1923
50.8 mm (2.0 in)
1924
39.6 mm (1.6 in)
1925
69.1 mm (2.7 in)
1926
64.0 mm (2.5 in)
1927
39.6 mm (1.6 in)
1928
36.1 mm (1.4 in)
1929
65.8 mm (2.6 in)
1930
72.4 mm (2.9 in)
1931
36.1 mm (1.4 in)
1932
62.2 mm (2.4 in)
1933
43.4 mm (1.7 in)
1934
48.6 mm (1.9 in)
1935
38.2 mm (1.5 in)
1936
70.4 mm (2.8 in)
1937
45.7 mm (1.8 in)
1938
68.6 mm (2.7 in)
1939
36.6 mm (1.4 in)
1940
64.9 mm (2.6 in)
1941
63.0 mm (2.5 in)
1942
58.0 mm (2.3 in)
1943
53.8 mm (2.1 in)
1944
50.9 mm (2.0 in)
1945
75.0 mm (3.0 in)
1946
58.9 mm (2.3 in)
1947
86.3 mm (3.4 in)
1948
40.4 mm (1.6 in)
1949
64.5 mm (2.5 in)
1950
43.4 mm (1.7 in)
1951
96.1 mm (3.8 in)
1952
49.3 mm (1.9 in)
1953
88.3 mm (3.5 in)
1954
72.9 mm (2.9 in)
1955
45.9 mm (1.8 in)
1956
43.2 mm (1.7 in)
1957
82.8 mm (3.3 in)
1958
34.1 mm (1.3 in)
1959
42.2 mm (1.7 in)
1960
42.4 mm (1.7 in)
1961
70.6 mm (2.8 in)
1962
34.8 mm (1.4 in)
1963
53.6 mm (2.1 in)
1964
57.6 mm (2.3 in)
1965
53.1 mm (2.1 in)
1966
51.5 mm (2.0 in)
1967
34.7 mm (1.4 in)
1968
63.0 mm (2.5 in)
1969
46.5 mm (1.8 in)
1970
76.2 mm (3.0 in)
1971
57.9 mm (2.3 in)
1972
44.8 mm (1.8 in)
1973
57.1 mm (2.2 in)
1974
63.6 mm (2.5 in)
1975
66.1 mm (2.6 in)
1976
59.2 mm (2.3 in)
1977
97.0 mm (3.8 in)
1978
61.3 mm (2.4 in)
1979
46.7 mm (1.8 in)
1980
69.3 mm (2.7 in)
1981
69.4 mm (2.7 in)
1982
101.1 mm (4.0 in)
1983
83.6 mm (3.3 in)
1984
54.9 mm (2.2 in)
1985
64.5 mm (2.5 in)
1986
68.4 mm (2.7 in)
1987
67.4 mm (2.7 in)
1988
56.4 mm (2.2 in)
1989
48.3 mm (1.9 in)
1990
25.1 mm (1.0 in)
1991
40.1 mm (1.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Riverdale, 1914 to 1991. The record is 94 days in 1944, marked on the chart; the median year is 39 days.
Longest dry spell (CDD) at Riverdale by year
Year
Longest dry spell (CDD)
1914
53 days
1915
50 days
1916
30 days
1917
27 days
1918
14 days
1919
19 days
1920
29 days
1921
17 days
1922
35 days
1923
31 days
1924
36 days
1925
3 days
1926
7 days
1927
28 days
1928
41 days
1929
52 days
1930
21 days
1931
63 days
1932
40 days
1933
39 days
1934
41 days
1935
76 days
1936
46 days
1937
35 days
1938
59 days
1939
59 days
1940
63 days
1941
17 days
1942
32 days
1943
62 days
1944
94 days
1945
53 days
1946
57 days
1947
41 days
1948
43 days
1949
35 days
1950
28 days
1951
34 days
1952
82 days
1953
78 days
1954
48 days
1955
25 days
1956
36 days
1957
23 days
1958
52 days
1959
49 days
1960
50 days
1961
31 days
1962
40 days
1963
78 days
1964
71 days
1965
27 days
1966
39 days
1967
42 days
1968
29 days
1969
50 days
1970
27 days
1971
42 days
1972
48 days
1973
26 days
1974
55 days
1975
26 days
1976
62 days
1977
48 days
1978
48 days
1979
36 days
1980
21 days
1981
41 days
1982
27 days
1983
19 days
1984
20 days
1985
28 days
1986
24 days
1987
38 days
1988
66 days
1989
35 days
1990
22 days
1991
27 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
61 years with a frost
Across 61 years with a frost, the median last spring frost at Riverdale falls on 11 May and the median first autumn frost on 11 October, which leaves a median of 152 days between them.
In 1955 to 1990 the median growing season was 144 days. That is 15 days fewer than in 1915 to 1953.
Fitted over all years, the growing season changes by -1.1 days per decade at this station.
Frost dates and growing season at Riverdale
Measure
Median, all years
Earliest period (1915 to 1953)
Recent period (1955 to 1990)
Recent against earliest
Fitted trend
Last spring frost
11 May
10 May
13 May
3 days later
+0.1 days per decade
First autumn frost
11 October
12 October
8 October
4 days earlier
-1.0 days per decade
Growing days
152 days
159 days
144 days
15 days fewer
-1.1 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
63 years, 1914 to 1990
A day with at least 34.4 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 65.7 mm (2.6 in) of rain is expected about once in 100 years.
Rainfall return levels at Riverdale: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
34.4 mm (1.4 in)
5 years
43.6 mm (1.7 in)
10 years
49.4 mm (1.9 in)
25 years
56.3 mm (2.2 in)
50 years
61.1 mm (2.4 in)
100 years
65.7 mm (2.6 in)
Longer than the 63 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, 63 years of values from 1914 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: 62.7 mm (2.5 in) in 1930; 62.0 mm (2.4 in) in 1951; 55.4 mm (2.2 in) in 1957.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Riverdale, at 1937. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1937 ran 0.5 C (0.9 F) higher than in the years before (possible change).
Suspected changes in the annual mean temperature at Riverdale, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1937
+0.5
+0.9
possible
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 Riverdale standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Riverdale 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.