Record envelope, standing records and threshold days for Grand River Dam (USC00343700), Oklahoma, United States, with 39 years of record.
Key Facts for Grand River Dam
Grand River Dam (USC00343700) is a weather station in Oklahoma, United States at 36.47 latitude and -95.05 longitude, 235 m (771 ft) above sea level.
The station reports from 1941 to 1979, 39 years of record.
1,464 records set at Grand River Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Grand River Dam set a daily record precipitation of 38.9 mm (1.5 in) on 24 June 1979.
About the Station
Location: Oklahoma, United States, 36.47 latitude, -95.05 longitude.
Elevation: 235 m (771 ft).
Period of record: 1941 to 1979, 39 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 Grand River Dam. 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 Grand River Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
26.1 C (79.0 F)
-22.2 C (-8.0 F)
n/a
n/a
Feb
28.9 C (84.0 F)
-21.1 C (-6.0 F)
n/a
n/a
Mar
32.2 C (90.0 F)
-21.7 C (-7.1 F)
n/a
n/a
Apr
35.0 C (95.0 F)
-6.7 C (19.9 F)
n/a
n/a
May
36.7 C (98.1 F)
0.0 C (32.0 F)
n/a
n/a
Jun
40.0 C (104.0 F)
7.8 C (46.0 F)
n/a
n/a
Jul
45.0 C (113.0 F)
9.4 C (48.9 F)
n/a
n/a
Aug
43.9 C (111.0 F)
8.9 C (48.0 F)
n/a
n/a
Sep
41.1 C (106.0 F)
0.6 C (33.1 F)
n/a
n/a
Oct
35.6 C (96.1 F)
-5.6 C (21.9 F)
n/a
n/a
Nov
31.1 C (88.0 F)
-15.0 C (5.0 F)
n/a
n/a
Dec
26.7 C (80.1 F)
-20.0 C (-4.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Grand River Dam still stand. 1954 holds the most, with 70.
Standing records at Grand River Dam by the year they were set
Year set
Standing records
1941
26
1942
35
1943
54
1944
32
1945
26
1946
33
1947
46
1948
48
1949
31
1950
68
1951
51
1952
60
1953
52
1954
70
1955
42
1956
54
1957
26
1958
30
1959
24
1960
41
1961
28
1962
33
1963
60
1964
41
1965
20
1966
33
1967
37
1968
35
1969
18
1970
33
1971
26
1972
49
1973
28
1974
27
1975
30
1976
43
1977
28
1978
33
1979
13
Wettest Day of Each Month
Aug: 188.0 mm (7.4 in)
The wettest day on record for each calendar month at Grand River Dam. The most was 188.0 mm (7.4 in) on 14 August 1961.
Record daily precipitation for each month at Grand River Dam
Month
Record daily precipitation (mm)
Date
Jan
38.1 mm (1.5 in)
3 January 1950
Feb
91.7 mm (3.6 in)
14 February 1951
Mar
77.5 mm (3.1 in)
11 March 1977
Apr
120.4 mm (4.7 in)
19 April 1941
May
123.4 mm (4.9 in)
17 May 1943
Jun
126.2 mm (5.0 in)
21 June 1948
Jul
121.4 mm (4.8 in)
12 July 1958
Aug
188.0 mm (7.4 in)
14 August 1961
Sep
130.3 mm (5.1 in)
24 September 1945
Oct
126.5 mm (5.0 in)
4 October 1941
Nov
102.6 mm (4.0 in)
1 November 1972
Dec
50.0 mm (2.0 in)
24 December 1965
Period of Record Coverage
1941 to 1979
Complete yearUnder 90 percent of days
39 years of record at Grand River Dam, 1941 to 1979. 7 years have data for under 90 percent of days and are left out of rankings: 1941, 1963, 1966, 1967, 1974, 1977, 1979.
Cooler than the station meanWarmer than the station mean
One stripe for each of 24 complete years at Grand River Dam, 1943 to 1976. Blue stripes are years cooler than the station's own mean of 15.3 C (59.5 F); red stripes are warmer. The coolest year was 1968, at 14.4 C (57.9 F), and the warmest was 1946, at 16.7 C (62.0 F). The strongest colour marks a difference of 1.4 C (2.5 F).
Annual mean temperature at Grand River Dam as warming stripes, 1943 to 1976
Year
Annual mean temperature
Difference from the station mean
1943
15.5 C
+0.21 C
1944
15.7 C
+0.43 C
1945
15.4 C
+0.14 C
1946
16.7 C
+1.40 C
1947
15.3 C
0.00 C
1948
14.5 C
-0.82 C
1949
15.0 C
-0.29 C
1950
14.7 C
-0.62 C
1951
15.1 C
-0.16 C
1952
15.7 C
+0.42 C
1955
15.8 C
+0.53 C
1956
16.2 C
+0.92 C
1958
14.6 C
-0.68 C
1959
14.9 C
-0.43 C
1960
14.5 C
-0.75 C
1961
14.9 C
-0.39 C
1962
15.4 C
+0.15 C
1964
16.1 C
+0.78 C
1968
14.4 C
-0.91 C
1969
15.0 C
-0.33 C
1971
15.8 C
+0.48 C
1972
15.3 C
-0.04 C
1975
15.7 C
+0.39 C
1976
14.9 C
-0.35 C
This station does not have enough complete years (30 are needed) to fit a temperature trend.
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
1941 to 1979
Yearly extremes at Grand River Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.0 C (113.0 F)
1954
39.4 C (102.9 F)
39
Coldest night (TNn)
-22.2 C (-8.0 F)
1943
-17.8 C (0.0 F)
39
Wettest day (Rx1day)
188.0 mm (7.4 in)
1961
82.0 mm (3.2 in)
39
Wettest five days (Rx5day)
260.0 mm (10.2 in)
1941
134.6 mm (5.3 in)
39
Longest dry spell (CDD)
55 days
1950
25 days
39
Hottest day (TXx)
The hottest day of the year at Grand River Dam, 1941 to 1979. The record is 45.0 C (113.0 F) in 1954, marked on the chart; the median year is 39.4 C (102.9 F).
Hottest day (TXx) at Grand River Dam by year
Year
Hottest day (TXx)
1941
38.3 C (100.9 F)
1942
38.9 C (102.0 F)
1943
42.2 C (108.0 F)
1944
40.0 C (104.0 F)
1945
39.4 C (102.9 F)
1946
41.7 C (107.1 F)
1947
41.1 C (106.0 F)
1948
38.9 C (102.0 F)
1949
39.4 C (102.9 F)
1950
35.6 C (96.1 F)
1951
41.1 C (106.0 F)
1952
40.0 C (104.0 F)
1953
39.4 C (102.9 F)
1954
45.0 C (113.0 F)
1955
37.8 C (100.0 F)
1956
43.9 C (111.0 F)
1957
41.1 C (106.0 F)
1958
37.8 C (100.0 F)
1959
36.7 C (98.1 F)
1960
37.8 C (100.0 F)
1961
35.6 C (96.1 F)
1962
39.4 C (102.9 F)
1963
40.6 C (105.1 F)
1964
41.1 C (106.0 F)
1965
39.4 C (102.9 F)
1966
39.4 C (102.9 F)
1967
36.1 C (97.0 F)
1968
37.8 C (100.0 F)
1969
41.1 C (106.0 F)
1970
41.7 C (107.1 F)
1971
37.2 C (99.0 F)
1972
40.0 C (104.0 F)
1973
37.8 C (100.0 F)
1974
42.2 C (108.0 F)
1975
40.0 C (104.0 F)
1976
38.3 C (100.9 F)
1977
41.7 C (107.1 F)
1978
41.1 C (106.0 F)
1979
35.6 C (96.1 F)
Coldest night (TNn)
The coldest night of the year at Grand River Dam, 1941 to 1979. The record is -22.2 C (-8.0 F) in 1943, marked on the chart; the median year is -17.8 C (0.0 F).
Coldest night (TNn) at Grand River Dam by year
Year
Coldest night (TNn)
1941
-7.8 C (18.0 F)
1942
-12.8 C (9.0 F)
1943
-22.2 C (-8.0 F)
1944
-17.8 C (0.0 F)
1945
-20.0 C (-4.0 F)
1946
-12.2 C (10.0 F)
1947
-20.0 C (-4.0 F)
1948
-21.7 C (-7.1 F)
1949
-18.9 C (-2.0 F)
1950
-18.3 C (-0.9 F)
1951
-19.4 C (-2.9 F)
1952
-11.1 C (12.0 F)
1953
-13.9 C (7.0 F)
1954
-16.1 C (3.0 F)
1955
-16.1 C (3.0 F)
1956
-14.4 C (6.1 F)
1957
-12.8 C (9.0 F)
1958
-17.8 C (0.0 F)
1959
-20.0 C (-4.0 F)
1960
-16.7 C (1.9 F)
1961
-16.7 C (1.9 F)
1962
-19.4 C (-2.9 F)
1963
-18.9 C (-2.0 F)
1964
-17.2 C (1.0 F)
1965
-15.6 C (3.9 F)
1966
-18.9 C (-2.0 F)
1967
-12.8 C (9.0 F)
1968
-20.0 C (-4.0 F)
1969
-14.4 C (6.1 F)
1970
-20.6 C (-5.1 F)
1971
-17.8 C (0.0 F)
1972
-17.8 C (0.0 F)
1973
-13.9 C (7.0 F)
1974
-14.4 C (6.1 F)
1975
-14.4 C (6.1 F)
1976
-17.8 C (0.0 F)
1977
-22.2 C (-8.0 F)
1978
-17.2 C (1.0 F)
1979
-21.1 C (-6.0 F)
Wettest day (Rx1day)
The wettest day of the year at Grand River Dam, 1941 to 1979. The record is 188.0 mm (7.4 in) in 1961, marked on the chart; the median year is 82.0 mm (3.2 in).
Wettest day (Rx1day) at Grand River Dam by year
Year
Wettest day (Rx1day)
1941
126.5 mm (5.0 in)
1942
74.9 mm (2.9 in)
1943
123.4 mm (4.9 in)
1944
63.5 mm (2.5 in)
1945
130.3 mm (5.1 in)
1946
87.9 mm (3.5 in)
1947
74.4 mm (2.9 in)
1948
126.2 mm (5.0 in)
1949
102.4 mm (4.0 in)
1950
103.9 mm (4.1 in)
1951
91.7 mm (3.6 in)
1952
46.7 mm (1.8 in)
1953
53.8 mm (2.1 in)
1954
50.8 mm (2.0 in)
1955
113.8 mm (4.5 in)
1956
66.0 mm (2.6 in)
1957
114.3 mm (4.5 in)
1958
121.4 mm (4.8 in)
1959
85.9 mm (3.4 in)
1960
89.9 mm (3.5 in)
1961
188.0 mm (7.4 in)
1962
67.3 mm (2.6 in)
1963
55.9 mm (2.2 in)
1964
109.7 mm (4.3 in)
1965
73.7 mm (2.9 in)
1966
43.9 mm (1.7 in)
1967
57.2 mm (2.3 in)
1968
82.0 mm (3.2 in)
1969
55.9 mm (2.2 in)
1970
76.2 mm (3.0 in)
1971
63.0 mm (2.5 in)
1972
102.6 mm (4.0 in)
1973
117.3 mm (4.6 in)
1974
76.7 mm (3.0 in)
1975
100.3 mm (3.9 in)
1976
76.2 mm (3.0 in)
1977
97.3 mm (3.8 in)
1978
68.3 mm (2.7 in)
1979
56.9 mm (2.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Grand River Dam, 1941 to 1979. The record is 260.0 mm (10.2 in) in 1941, marked on the chart; the median year is 134.6 mm (5.3 in).
Wettest five days (Rx5day) at Grand River Dam by year
Year
Wettest five days (Rx5day)
1941
260.0 mm (10.2 in)
1942
121.2 mm (4.8 in)
1943
198.2 mm (7.8 in)
1944
73.8 mm (2.9 in)
1945
214.7 mm (8.5 in)
1946
147.3 mm (5.8 in)
1947
104.7 mm (4.1 in)
1948
218.7 mm (8.6 in)
1949
150.6 mm (5.9 in)
1950
137.9 mm (5.4 in)
1951
122.2 mm (4.8 in)
1952
65.7 mm (2.6 in)
1953
82.6 mm (3.3 in)
1954
112.7 mm (4.4 in)
1955
154.7 mm (6.1 in)
1956
116.8 mm (4.6 in)
1957
233.2 mm (9.2 in)
1958
127.5 mm (5.0 in)
1959
259.0 mm (10.2 in)
1960
138.7 mm (5.5 in)
1961
220.2 mm (8.7 in)
1962
100.4 mm (4.0 in)
1963
69.6 mm (2.7 in)
1964
204.3 mm (8.0 in)
1965
115.4 mm (4.5 in)
1966
78.2 mm (3.1 in)
1967
103.1 mm (4.1 in)
1968
106.4 mm (4.2 in)
1969
119.7 mm (4.7 in)
1970
134.6 mm (5.3 in)
1971
86.4 mm (3.4 in)
1972
142.0 mm (5.6 in)
1973
145.5 mm (5.7 in)
1974
152.9 mm (6.0 in)
1975
120.0 mm (4.7 in)
1976
140.4 mm (5.5 in)
1977
139.7 mm (5.5 in)
1978
171.2 mm (6.7 in)
1979
89.7 mm (3.5 in)
Longest dry spell (CDD)
The longest dry spell of the year at Grand River Dam, 1941 to 1979. The record is 55 days in 1950, marked on the chart; the median year is 25 days.
Longest dry spell (CDD) at Grand River Dam by year
Year
Longest dry spell (CDD)
1941
14 days
1942
15 days
1943
35 days
1944
29 days
1945
18 days
1946
35 days
1947
25 days
1948
50 days
1949
21 days
1950
55 days
1951
17 days
1952
33 days
1953
25 days
1954
36 days
1955
24 days
1956
27 days
1957
33 days
1958
18 days
1959
30 days
1960
28 days
1961
21 days
1962
27 days
1963
39 days
1964
20 days
1965
19 days
1966
29 days
1967
26 days
1968
24 days
1969
22 days
1970
19 days
1971
24 days
1972
29 days
1973
19 days
1974
19 days
1975
20 days
1976
25 days
1977
20 days
1978
41 days
1979
13 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
24 years with a frost
Across 24 years with a frost, the median last spring frost at Grand River Dam falls on 9 April and the median first autumn frost on 1 November, which leaves a median of 205 days between them.
Frost dates and growing season at Grand River Dam
Measure
Median, all years
Earliest period
Recent period (1943 to 1976)
Recent against earliest
Fitted trend
Last spring frost
9 April
n/a
9 April
n/a
n/a
First autumn frost
1 November
n/a
1 November
n/a
n/a
Growing days
205 days
n/a
205 days
n/a
n/a
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
36 years, 1942 to 1978
A day with at least 84.1 mm (3.3 in) of rain is expected about once in 2 years. A day with at least 177.0 mm (7.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Grand River Dam: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
84.1 mm (3.3 in)
5 years
110.9 mm (4.4 in)
10 years
127.9 mm (5.0 in)
25 years
148.4 mm (5.8 in)
50 years
163.0 mm (6.4 in)
Longer than the 36 years of record
100 years
177.0 mm (7.0 in)
Longer than the 36 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, 36 years of values from 1942 to 1978.
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: 188.0 mm (7.4 in) in 1961; 130.3 mm (5.1 in) in 1945; 126.2 mm (5.0 in) in 1948.
Download the Data
Data for Grand River Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Grand River Dam 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.