Record envelope, standing records and threshold days for Blackwell 1 W (USC00340814), Oklahoma, United States, with 59 years of record.
Key Facts for Blackwell 1 W
Blackwell 1 W (USC00340814) is a weather station in Oklahoma, United States at 36.80 latitude and -97.30 longitude, 317 m (1,040 ft) above sea level.
The station reports from 1916 to 1974, 59 years of record.
1,464 records set at Blackwell 1 W still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Blackwell 1 W set a daily record low maximum temperature of 10.6 C (51.1 F) on 7 October 1974.
About the Station
Location: Oklahoma, United States, 36.80 latitude, -97.30 longitude.
Elevation: 317 m (1,040 ft).
Period of record: 1916 to 1974, 59 years.
Eligible elements: tmax, tmin, prcp, snow.
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 Blackwell 1 W. 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 Blackwell 1 W, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.6 C (78.1 F)
-28.9 C (-20.0 F)
n/a
n/a
Feb
30.0 C (86.0 F)
-21.1 C (-6.0 F)
n/a
n/a
Mar
33.9 C (93.0 F)
-17.8 C (0.0 F)
n/a
n/a
Apr
38.9 C (102.0 F)
-7.8 C (18.0 F)
n/a
n/a
May
40.6 C (105.1 F)
-0.6 C (30.9 F)
n/a
n/a
Jun
45.6 C (114.1 F)
7.2 C (45.0 F)
n/a
n/a
Jul
46.7 C (116.1 F)
9.4 C (48.9 F)
n/a
n/a
Aug
45.0 C (113.0 F)
8.9 C (48.0 F)
n/a
n/a
Sep
43.3 C (109.9 F)
-1.7 C (28.9 F)
n/a
n/a
Oct
38.3 C (100.9 F)
-9.4 C (15.1 F)
n/a
n/a
Nov
31.1 C (88.0 F)
-13.9 C (7.0 F)
n/a
n/a
Dec
28.9 C (84.0 F)
-22.2 C (-8.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Blackwell 1 W still stand. 1956 holds the most, with 87.
Standing records at Blackwell 1 W by the year they were set
Year set
Standing records
1916
19
1917
28
1918
47
1919
23
1920
31
1921
23
1922
26
1923
19
1924
33
1925
30
1926
18
1927
32
1928
23
1929
20
1930
38
1931
30
1937
9
1938
36
1939
39
1940
27
1941
5
1942
18
1943
32
1944
15
1945
16
1946
19
1947
47
1948
25
1949
14
1950
30
1951
33
1952
28
1953
45
1954
50
1955
33
1956
87
1957
20
1958
37
1959
27
1960
29
1961
19
1962
27
1963
23
1964
27
1965
16
1966
32
1967
30
1968
26
1969
10
1970
23
1971
18
1972
30
1973
10
1974
12
All-Time Record Progression
6 new records
6 all-time records were set at Blackwell 1 W between 15 June 1953 and 16 March 1970. Each dot is a new record.
When Blackwell 1 W set new all-time records
Date
Kind
Detail
1953-06-15
Record high maximum temperature
Record high maximum temperature 45.6 C (114.1 F)
1954-07-14
Record high maximum temperature
Record high maximum temperature 46.7 C (116.1 F)
1956-07-01
Record high minimum temperature
Record high minimum temperature 28.9 C (84.0 F)
1956-08-17
Record high minimum temperature
Record high minimum temperature 30.0 C (86.0 F)
1963-07-11
Record daily precipitation
Record daily precipitation 182.1 mm (7.2 in)
1970-03-16
Record daily snowfall
Record daily snowfall 33.0 cm (13.0 in)
Wettest Day of Each Month
Jul: 182.1 mm (7.2 in)
The wettest day on record for each calendar month at Blackwell 1 W. The most was 182.1 mm (7.2 in) on 11 July 1963.
Record daily precipitation for each month at Blackwell 1 W
Month
Record daily precipitation (mm)
Date
Jan
55.1 mm (2.2 in)
26 January 1967
Feb
59.9 mm (2.4 in)
20 February 1951
Mar
81.3 mm (3.2 in)
10 March 1974
Apr
92.5 mm (3.6 in)
25 April 1964
May
110.5 mm (4.4 in)
10 May 1948
Jun
110.2 mm (4.3 in)
20 June 1928
Jul
182.1 mm (7.2 in)
11 July 1963
Aug
70.4 mm (2.8 in)
19 August 1933
Sep
134.6 mm (5.3 in)
18 September 1921
Oct
167.6 mm (6.6 in)
2 October 1955
Nov
79.0 mm (3.1 in)
1 November 1922
Dec
55.9 mm (2.2 in)
19 December 1933
Period of Record Coverage
1916 to 1974
Complete yearUnder 90 percent of days
54 years of record at Blackwell 1 W, 1916 to 1974. 4 years have data for under 90 percent of days and are left out of rankings: 1916, 1917, 1937, 1950.
Cooler than the station meanWarmer than the station mean
One stripe for each of 46 complete years at Blackwell 1 W, 1918 to 1973. Blue stripes are years cooler than the station's own mean of 15.5 C (60.0 F); red stripes are warmer. The coolest year was 1942, at 14.5 C (58.1 F), and the warmest was 1954, at 17.9 C (64.2 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at Blackwell 1 W as warming stripes, 1918 to 1973
Year
Annual mean temperature
Difference from the station mean
1918
14.8 C
-0.75 C
1919
14.5 C
-1.00 C
1920
14.9 C
-0.66 C
1921
16.7 C
+1.14 C
1923
15.6 C
+0.02 C
1924
14.6 C
-0.95 C
1925
15.7 C
+0.15 C
1926
15.1 C
-0.42 C
1927
15.4 C
-0.11 C
1928
15.5 C
0.00 C
1929
14.5 C
-0.99 C
1930
15.5 C
0.00 C
1931
16.5 C
+0.98 C
1938
16.7 C
+1.12 C
1939
16.4 C
+0.82 C
1940
14.6 C
-0.89 C
1942
14.5 C
-1.04 C
1944
14.5 C
-1.01 C
1945
14.5 C
-1.04 C
1946
16.6 C
+1.05 C
1947
15.8 C
+0.25 C
1948
15.5 C
-0.01 C
1949
15.3 C
-0.25 C
1951
14.9 C
-0.67 C
1952
16.1 C
+0.59 C
1953
16.7 C
+1.13 C
1954
17.9 C
+2.38 C
1955
16.3 C
+0.79 C
1956
17.4 C
+1.89 C
1957
15.2 C
-0.32 C
1958
15.2 C
-0.31 C
1959
15.5 C
0.00 C
1960
14.9 C
-0.61 C
1961
14.8 C
-0.77 C
1962
15.7 C
+0.14 C
1963
15.9 C
+0.35 C
1964
15.8 C
+0.30 C
1965
16.1 C
+0.60 C
1966
14.8 C
-0.69 C
1967
15.5 C
-0.08 C
1968
14.9 C
-0.61 C
1969
15.3 C
-0.24 C
1970
15.7 C
+0.16 C
1971
15.5 C
-0.01 C
1972
15.4 C
-0.17 C
1973
15.3 C
-0.21 C
The fitted trend in annual mean temperature here over 1918 to 1973 is 0.1 C (-0.1 to 0.2) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.2 to 0.4) per decade. The slope is a straight line fitted to 46 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Blackwell 1 W
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (-0.1 to 0.2) per decade
0.1 F (-0.2 to 0.4) per decade
1918 to 1973
46
Not clearly different from zero
Mean daily maximum
0.1 C (-0.1 to 0.3) per decade
0.1 F (-0.2 to 0.5) per decade
1918 to 1973
46
Not clearly different from zero
Mean daily minimum
0.03 C (-0.08 to 0.14) per decade
0.1 F (-0.1 to 0.3) per decade
1918 to 1973
46
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
1916 to 1974
Yearly extremes at Blackwell 1 W: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
46.7 C (116.1 F)
1954
41.1 C (106.0 F)
54
Coldest night (TNn)
-28.9 C (-20.0 F)
1930
-17.5 C (0.5 F)
54
Wettest day (Rx1day)
182.1 mm (7.2 in)
1963
76.7 mm (3.0 in)
59
Wettest five days (Rx5day)
198.2 mm (7.8 in)
1959
107.7 mm (4.2 in)
59
Longest dry spell (CDD)
82 days
1930
32 days
59
Hottest day (TXx)
The hottest day of the year at Blackwell 1 W, 1916 to 1974. The record is 46.7 C (116.1 F) in 1954, marked on the chart; the median year is 41.1 C (106.0 F).
Hottest day (TXx) at Blackwell 1 W by year
Year
Hottest day (TXx)
1916
41.1 C (106.0 F)
1917
37.8 C (100.0 F)
1918
41.7 C (107.1 F)
1919
41.1 C (106.0 F)
1920
37.2 C (99.0 F)
1921
40.0 C (104.0 F)
1922
42.8 C (109.0 F)
1923
42.2 C (108.0 F)
1924
39.4 C (102.9 F)
1925
40.0 C (104.0 F)
1926
41.1 C (106.0 F)
1927
37.8 C (100.0 F)
1928
38.9 C (102.0 F)
1929
42.2 C (108.0 F)
1930
41.7 C (107.1 F)
1931
41.1 C (106.0 F)
1932
n/a
1933
n/a
1934
n/a
1935
n/a
1936
n/a
1937
28.9 C (84.0 F)
1938
39.4 C (102.9 F)
1939
42.2 C (108.0 F)
1940
40.6 C (105.1 F)
1941
38.9 C (102.0 F)
1942
40.6 C (105.1 F)
1943
41.7 C (107.1 F)
1944
41.1 C (106.0 F)
1945
41.1 C (106.0 F)
1946
43.9 C (111.0 F)
1947
43.9 C (111.0 F)
1948
40.0 C (104.0 F)
1949
40.6 C (105.1 F)
1950
38.9 C (102.0 F)
1951
43.9 C (111.0 F)
1952
42.2 C (108.0 F)
1953
45.6 C (114.1 F)
1954
46.7 C (116.1 F)
1955
40.0 C (104.0 F)
1956
45.0 C (113.0 F)
1957
42.8 C (109.0 F)
1958
41.1 C (106.0 F)
1959
42.2 C (108.0 F)
1960
39.4 C (102.9 F)
1961
39.4 C (102.9 F)
1962
42.2 C (108.0 F)
1963
40.6 C (105.1 F)
1964
43.3 C (109.9 F)
1965
40.6 C (105.1 F)
1966
40.6 C (105.1 F)
1967
40.0 C (104.0 F)
1968
41.7 C (107.1 F)
1969
41.7 C (107.1 F)
1970
42.8 C (109.0 F)
1971
42.2 C (108.0 F)
1972
40.0 C (104.0 F)
1973
40.6 C (105.1 F)
1974
42.8 C (109.0 F)
Coldest night (TNn)
The coldest night of the year at Blackwell 1 W, 1916 to 1974. The record is -28.9 C (-20.0 F) in 1930, marked on the chart; the median year is -17.5 C (0.5 F).
Coldest night (TNn) at Blackwell 1 W by year
Year
Coldest night (TNn)
1916
-3.9 C (25.0 F)
1917
-20.0 C (-4.0 F)
1918
-23.3 C (-9.9 F)
1919
-21.7 C (-7.1 F)
1920
-18.9 C (-2.0 F)
1921
-14.4 C (6.1 F)
1922
-21.7 C (-7.1 F)
1923
-16.7 C (1.9 F)
1924
-19.4 C (-2.9 F)
1925
-16.1 C (3.0 F)
1926
-15.0 C (5.0 F)
1927
-18.3 C (-0.9 F)
1928
-18.9 C (-2.0 F)
1929
-21.1 C (-6.0 F)
1930
-28.9 C (-20.0 F)
1931
-11.7 C (10.9 F)
1932
n/a
1933
n/a
1934
n/a
1935
n/a
1936
n/a
1937
-12.2 C (10.0 F)
1938
-15.0 C (5.0 F)
1939
-17.2 C (1.0 F)
1940
-21.1 C (-6.0 F)
1941
-8.9 C (16.0 F)
1942
-18.9 C (-2.0 F)
1943
-21.1 C (-6.0 F)
1944
-17.8 C (0.0 F)
1945
-16.1 C (3.0 F)
1946
-13.9 C (7.0 F)
1947
-23.9 C (-11.0 F)
1948
-15.6 C (3.9 F)
1949
-20.6 C (-5.1 F)
1950
-17.8 C (0.0 F)
1951
-21.1 C (-6.0 F)
1952
-11.1 C (12.0 F)
1953
-13.9 C (7.0 F)
1954
-17.2 C (1.0 F)
1955
-12.2 C (10.0 F)
1956
-14.4 C (6.1 F)
1957
-12.8 C (9.0 F)
1958
-20.0 C (-4.0 F)
1959
-20.6 C (-5.1 F)
1960
-17.8 C (0.0 F)
1961
-16.1 C (3.0 F)
1962
-22.2 C (-8.0 F)
1963
-21.1 C (-6.0 F)
1964
-16.1 C (3.0 F)
1965
-14.4 C (6.1 F)
1966
-18.9 C (-2.0 F)
1967
-16.7 C (1.9 F)
1968
-18.9 C (-2.0 F)
1969
-12.2 C (10.0 F)
1970
-16.7 C (1.9 F)
1971
-16.1 C (3.0 F)
1972
-18.9 C (-2.0 F)
1973
-20.6 C (-5.1 F)
1974
-16.7 C (1.9 F)
Wettest day (Rx1day)
The wettest day of the year at Blackwell 1 W, 1916 to 1974. The record is 182.1 mm (7.2 in) in 1963, marked on the chart; the median year is 76.7 mm (3.0 in).
Wettest day (Rx1day) at Blackwell 1 W by year
Year
Wettest day (Rx1day)
1916
81.5 mm (3.2 in)
1917
84.8 mm (3.3 in)
1918
69.9 mm (2.8 in)
1919
102.1 mm (4.0 in)
1920
53.3 mm (2.1 in)
1921
134.6 mm (5.3 in)
1922
79.0 mm (3.1 in)
1923
77.7 mm (3.1 in)
1924
69.3 mm (2.7 in)
1925
113.5 mm (4.5 in)
1926
47.2 mm (1.9 in)
1927
70.1 mm (2.8 in)
1928
110.2 mm (4.3 in)
1929
92.2 mm (3.6 in)
1930
69.9 mm (2.8 in)
1931
43.9 mm (1.7 in)
1932
170.2 mm (6.7 in)
1933
70.4 mm (2.8 in)
1934
72.9 mm (2.9 in)
1935
89.4 mm (3.5 in)
1936
91.4 mm (3.6 in)
1937
64.5 mm (2.5 in)
1938
47.0 mm (1.9 in)
1939
69.9 mm (2.8 in)
1940
37.6 mm (1.5 in)
1941
78.5 mm (3.1 in)
1942
96.0 mm (3.8 in)
1943
72.6 mm (2.9 in)
1944
94.0 mm (3.7 in)
1945
82.6 mm (3.3 in)
1946
28.4 mm (1.1 in)
1947
42.9 mm (1.7 in)
1948
110.5 mm (4.4 in)
1949
54.6 mm (2.1 in)
1950
55.9 mm (2.2 in)
1951
94.0 mm (3.7 in)
1952
68.6 mm (2.7 in)
1953
51.3 mm (2.0 in)
1954
59.4 mm (2.3 in)
1955
167.6 mm (6.6 in)
1956
41.9 mm (1.6 in)
1957
76.7 mm (3.0 in)
1958
67.3 mm (2.6 in)
1959
122.7 mm (4.8 in)
1960
64.3 mm (2.5 in)
1961
132.3 mm (5.2 in)
1962
71.6 mm (2.8 in)
1963
182.1 mm (7.2 in)
1964
92.5 mm (3.6 in)
1965
59.4 mm (2.3 in)
1966
62.5 mm (2.5 in)
1967
112.3 mm (4.4 in)
1968
78.5 mm (3.1 in)
1969
94.5 mm (3.7 in)
1970
66.5 mm (2.6 in)
1971
78.5 mm (3.1 in)
1972
51.8 mm (2.0 in)
1973
98.8 mm (3.9 in)
1974
81.3 mm (3.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Blackwell 1 W, 1916 to 1974. The record is 198.2 mm (7.8 in) in 1959, marked on the chart; the median year is 107.7 mm (4.2 in).
Wettest five days (Rx5day) at Blackwell 1 W by year
Year
Wettest five days (Rx5day)
1916
135.3 mm (5.3 in)
1917
86.1 mm (3.4 in)
1918
98.1 mm (3.9 in)
1919
107.4 mm (4.2 in)
1920
145.5 mm (5.7 in)
1921
139.7 mm (5.5 in)
1922
128.3 mm (5.1 in)
1923
110.5 mm (4.4 in)
1924
78.5 mm (3.1 in)
1925
116.0 mm (4.6 in)
1926
107.7 mm (4.2 in)
1927
127.3 mm (5.0 in)
1928
131.4 mm (5.2 in)
1929
92.7 mm (3.6 in)
1930
69.9 mm (2.8 in)
1931
74.2 mm (2.9 in)
1932
180.4 mm (7.1 in)
1933
92.5 mm (3.6 in)
1934
90.4 mm (3.6 in)
1935
136.4 mm (5.4 in)
1936
139.2 mm (5.5 in)
1937
74.2 mm (2.9 in)
1938
101.1 mm (4.0 in)
1939
92.7 mm (3.6 in)
1940
68.6 mm (2.7 in)
1941
93.5 mm (3.7 in)
1942
163.6 mm (6.4 in)
1943
122.9 mm (4.8 in)
1944
125.0 mm (4.9 in)
1945
179.6 mm (7.1 in)
1946
47.4 mm (1.9 in)
1947
99.3 mm (3.9 in)
1948
110.5 mm (4.4 in)
1949
96.3 mm (3.8 in)
1950
81.5 mm (3.2 in)
1951
148.9 mm (5.9 in)
1952
68.6 mm (2.7 in)
1953
82.3 mm (3.2 in)
1954
59.4 mm (2.3 in)
1955
192.0 mm (7.6 in)
1956
44.4 mm (1.7 in)
1957
111.2 mm (4.4 in)
1958
120.7 mm (4.8 in)
1959
198.2 mm (7.8 in)
1960
97.6 mm (3.8 in)
1961
142.7 mm (5.6 in)
1962
72.4 mm (2.9 in)
1963
196.8 mm (7.7 in)
1964
151.7 mm (6.0 in)
1965
83.3 mm (3.3 in)
1966
83.6 mm (3.3 in)
1967
134.4 mm (5.3 in)
1968
97.0 mm (3.8 in)
1969
138.2 mm (5.4 in)
1970
121.4 mm (4.8 in)
1971
106.4 mm (4.2 in)
1972
69.3 mm (2.7 in)
1973
133.1 mm (5.2 in)
1974
125.0 mm (4.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at Blackwell 1 W, 1916 to 1974. The record is 82 days in 1930, marked on the chart; the median year is 32 days.
Longest dry spell (CDD) at Blackwell 1 W by year
Year
Longest dry spell (CDD)
1916
24 days
1917
39 days
1918
31 days
1919
35 days
1920
37 days
1921
62 days
1922
25 days
1923
22 days
1924
29 days
1925
27 days
1926
42 days
1927
31 days
1928
23 days
1929
30 days
1930
82 days
1931
24 days
1932
31 days
1933
28 days
1934
34 days
1935
29 days
1936
51 days
1937
22 days
1938
50 days
1939
59 days
1940
29 days
1941
20 days
1942
35 days
1943
42 days
1944
30 days
1945
49 days
1946
33 days
1947
26 days
1948
24 days
1949
57 days
1950
58 days
1951
19 days
1952
52 days
1953
31 days
1954
61 days
1955
57 days
1956
41 days
1957
25 days
1958
21 days
1959
40 days
1960
27 days
1961
35 days
1962
32 days
1963
57 days
1964
32 days
1965
44 days
1966
64 days
1967
25 days
1968
22 days
1969
23 days
1970
52 days
1971
47 days
1972
36 days
1973
23 days
1974
20 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
46 years with a frost
Across 46 years with a frost, the median last spring frost at Blackwell 1 W falls on 10 April and the median first autumn frost on 31 October, which leaves a median of 200 days between them.
Fitted over all years, the growing season changes by 0.0 days per decade at this station.
Frost dates and growing season at Blackwell 1 W
Measure
Median, all years
Earliest period
Recent period (1942 to 1973)
Recent against earliest
Fitted trend
Last spring frost
10 April
n/a
10 April
n/a
-1.0 days per decade
First autumn frost
31 October
n/a
29 October
n/a
-1.0 days per decade
Growing days
200 days
n/a
200 days
n/a
0.0 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
54 years, 1918 to 1974
A day with at least 74.9 mm (2.9 in) of rain is expected about once in 2 years. A day with at least 178.6 mm (7.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Blackwell 1 W: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
74.9 mm (2.9 in)
5 years
101.4 mm (4.0 in)
10 years
119.5 mm (4.7 in)
25 years
142.9 mm (5.6 in)
50 years
160.6 mm (6.3 in)
100 years
178.6 mm (7.0 in)
Longer than the 54 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, 54 years of values from 1918 to 1974.
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: 182.1 mm (7.2 in) in 1963; 167.6 mm (6.6 in) in 1955; 134.6 mm (5.3 in) in 1921.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Blackwell 1 W standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Blackwell 1 W 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.