Record envelope, standing records and threshold days for Blackwell 1SSW (USC00340818), Oklahoma, United States, with 74 years of record.
Key Facts for Blackwell 1SSW
Blackwell 1SSW (USC00340818) is a weather station in Oklahoma, United States at 36.78 latitude and -97.29 longitude, 315 m (1,033 ft) above sea level.
The station reports from 1953 to 2026, 74 years of record.
1,464 records set at Blackwell 1SSW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Blackwell 1SSW set a daily record precipitation of 71.1 mm (2.8 in) on 22 June 2026.
About the Station
Location: Oklahoma, United States, 36.78 latitude, -97.29 longitude.
Elevation: 315 m (1,033 ft).
Period of record: 1953 to 2026, 74 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 Blackwell 1SSW. 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 1SSW, 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)
-23.3 C (-9.9 F)
n/a
n/a
Feb
33.3 C (91.9 F)
-28.9 C (-20.0 F)
n/a
n/a
Mar
32.8 C (91.0 F)
-17.8 C (0.0 F)
n/a
n/a
Apr
36.7 C (98.1 F)
-7.2 C (19.0 F)
n/a
n/a
May
40.0 C (104.0 F)
0.6 C (33.1 F)
n/a
n/a
Jun
42.8 C (109.0 F)
7.8 C (46.0 F)
n/a
n/a
Jul
45.6 C (114.1 F)
9.4 C (48.9 F)
n/a
n/a
Aug
45.6 C (114.1 F)
7.8 C (46.0 F)
n/a
n/a
Sep
42.2 C (108.0 F)
-1.7 C (28.9 F)
n/a
n/a
Oct
36.7 C (98.1 F)
-9.4 C (15.1 F)
n/a
n/a
Nov
32.2 C (90.0 F)
-14.4 C (6.1 F)
n/a
n/a
Dec
26.7 C (80.1 F)
-24.4 C (-11.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Blackwell 1SSW still stand. 1956 holds the most, with 73.
Standing records at Blackwell 1SSW by the year they were set
Year set
Standing records
1954
1
1955
41
1956
73
1957
12
1958
33
1959
28
1960
26
1961
19
1962
46
1963
25
1964
28
1965
23
1966
41
1967
42
1968
22
1969
9
1970
3
1971
16
1972
20
1973
12
1974
17
1975
17
1976
28
1977
14
1978
32
1979
19
1980
30
1981
24
1982
15
1983
22
1984
23
1985
20
1986
24
1987
10
1988
15
1989
28
1990
22
1991
30
1992
13
1993
17
1994
13
1995
21
1996
29
1997
10
1998
24
1999
20
2000
23
2001
5
2002
14
2003
13
2004
20
2005
11
2006
32
2007
23
2008
10
2009
18
2010
10
2011
48
2012
38
2013
30
2014
34
2015
19
2016
17
2017
16
2018
24
2019
2
All-Time Record Progression
6 new records
6 all-time records were set at Blackwell 1SSW between 22 December 1989 and 11 February 2011. Each dot is a new record.
When Blackwell 1SSW set new all-time records
Date
Kind
Detail
1989-12-22
Record low maximum temperature
Record low maximum temperature -16.7 C (1.9 F)
1989-12-22
Record low minimum temperature
Record low minimum temperature -24.4 C (-11.9 F)
1990-06-17
Record high minimum temperature
Record high minimum temperature 28.3 C (82.9 F)
2009-08-18
Record daily precipitation
Record daily precipitation 174.0 mm (6.9 in)
2011-02-10
Record low minimum temperature
Record low minimum temperature -28.3 C (-18.9 F)
2011-02-11
Record low minimum temperature
Record low minimum temperature -28.9 C (-20.0 F)
Wettest Day of Each Month
Aug: 174.0 mm (6.9 in)
The wettest day on record for each calendar month at Blackwell 1SSW. The most was 174.0 mm (6.9 in) on 18 August 2009.
Record daily precipitation for each month at Blackwell 1SSW
Month
Record daily precipitation (mm)
Date
Jan
63.5 mm (2.5 in)
5 January 2005
Feb
87.6 mm (3.4 in)
21 February 1997
Mar
88.9 mm (3.5 in)
18 March 1992
Apr
152.4 mm (6.0 in)
30 April 2012
May
140.7 mm (5.5 in)
24 May 2015
Jun
124.5 mm (4.9 in)
11 June 1989
Jul
111.8 mm (4.4 in)
31 July 1979
Aug
174.0 mm (6.9 in)
18 August 2009
Sep
155.2 mm (6.1 in)
13 September 1961
Oct
145.8 mm (5.7 in)
2 October 1955
Nov
144.3 mm (5.7 in)
21 November 1979
Dec
53.6 mm (2.1 in)
27 December 2018
Period of Record Coverage
1954 to 2019
Complete yearUnder 90 percent of days
66 years of record at Blackwell 1SSW, 1954 to 2019. 8 years have data for under 90 percent of days and are left out of rankings: 1954, 1957, 1969, 1970, 1972, 1973, 2002, 2019.
Cooler than the station meanWarmer than the station mean
One stripe for each of 53 complete years at Blackwell 1SSW, 1955 to 2018. Blue stripes are years cooler than the station's own mean of 15.0 C (59.0 F); red stripes are warmer. The coolest year was 1979, at 13.7 C (56.7 F), and the warmest was 2012, at 16.9 C (62.4 F). The strongest colour marks a difference of 2.0 C (3.6 F).
Annual mean temperature at Blackwell 1SSW as warming stripes, 1955 to 2018
Year
Annual mean temperature
Difference from the station mean
1955
15.7 C
+0.73 C
1956
16.5 C
+1.51 C
1958
14.6 C
-0.38 C
1959
14.7 C
-0.28 C
1960
14.4 C
-0.63 C
1961
14.2 C
-0.79 C
1962
15.4 C
+0.40 C
1963
15.8 C
+0.77 C
1964
15.5 C
+0.47 C
1965
15.7 C
+0.74 C
1966
14.7 C
-0.24 C
1967
14.8 C
-0.19 C
1968
14.3 C
-0.64 C
1974
14.7 C
-0.29 C
1975
14.4 C
-0.59 C
1976
14.8 C
-0.14 C
1977
15.7 C
+0.74 C
1978
14.3 C
-0.72 C
1979
13.7 C
-1.25 C
1980
15.4 C
+0.44 C
1981
15.8 C
+0.79 C
1982
14.5 C
-0.51 C
1983
14.1 C
-0.92 C
1984
14.9 C
-0.04 C
1986
15.9 C
+0.87 C
1987
15.3 C
+0.30 C
1988
14.7 C
-0.24 C
1989
13.9 C
-1.05 C
1990
15.7 C
+0.76 C
1991
15.7 C
+0.72 C
1992
14.9 C
-0.12 C
1993
13.9 C
-1.09 C
1995
16.0 C
+1.01 C
1997
14.6 C
-0.42 C
1998
15.7 C
+0.74 C
1999
15.1 C
+0.16 C
2000
14.7 C
-0.24 C
2003
14.4 C
-0.62 C
2004
14.7 C
-0.31 C
2005
15.0 C
+0.03 C
2006
15.8 C
+0.80 C
2007
14.8 C
-0.23 C
2008
14.1 C
-0.91 C
2009
14.3 C
-0.71 C
2010
15.2 C
+0.20 C
2011
15.6 C
+0.65 C
2012
16.9 C
+1.91 C
2013
13.7 C
-1.24 C
2014
14.1 C
-0.89 C
2015
15.4 C
+0.41 C
2016
15.9 C
+0.87 C
2017
15.5 C
+0.49 C
2018
14.0 C
-0.96 C
The fitted trend in annual mean temperature here over 1955 to 2018 is -0.01 C (-0.12 to 0.09) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.03 F (-0.22 to 0.17) per decade. The slope is a straight line fitted to 53 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Blackwell 1SSW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.01 C (-0.12 to 0.09) per decade
-0.03 F (-0.22 to 0.17) per decade
1955 to 2018
53
Not clearly different from zero
Mean daily maximum
-0.01 C (-0.15 to 0.13) per decade
-0.02 F (-0.28 to 0.24) per decade
1955 to 2018
53
Not clearly different from zero
Mean daily minimum
-0.02 C (-0.12 to 0.08) per decade
-0.04 F (-0.21 to 0.14) per decade
1955 to 2018
53
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
1953 to 2026
Yearly extremes at Blackwell 1SSW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.6 C (114.1 F)
1956
41.1 C (106.0 F)
66
Coldest night (TNn)
-28.9 C (-20.0 F)
2011
-16.1 C (3.0 F)
66
Wettest day (Rx1day)
174.0 mm (6.9 in)
2009
81.8 mm (3.2 in)
74
Wettest five days (Rx5day)
226.0 mm (8.9 in)
2012
118.3 mm (4.7 in)
74
Longest dry spell (CDD)
64 days
1966
30 days
74
Hottest day (TXx)
The hottest day of the year at Blackwell 1SSW, 1953 to 2026. The record is 45.6 C (114.1 F) in 1956, marked on the chart; the median year is 41.1 C (106.0 F).
Hottest day (TXx) at Blackwell 1SSW by year
Year
Hottest day (TXx)
1953
n/a
1954
26.7 C (80.1 F)
1955
41.1 C (106.0 F)
1956
45.6 C (114.1 F)
1957
41.7 C (107.1 F)
1958
40.0 C (104.0 F)
1959
40.6 C (105.1 F)
1960
40.0 C (104.0 F)
1961
38.9 C (102.0 F)
1962
42.8 C (109.0 F)
1963
41.1 C (106.0 F)
1964
45.6 C (114.1 F)
1965
41.1 C (106.0 F)
1966
41.7 C (107.1 F)
1967
40.0 C (104.0 F)
1968
42.8 C (109.0 F)
1969
42.8 C (109.0 F)
1970
28.9 C (84.0 F)
1971
42.2 C (108.0 F)
1972
40.0 C (104.0 F)
1973
39.4 C (102.9 F)
1974
43.3 C (109.9 F)
1975
38.9 C (102.0 F)
1976
41.7 C (107.1 F)
1977
41.7 C (107.1 F)
1978
42.8 C (109.0 F)
1979
40.0 C (104.0 F)
1980
43.9 C (111.0 F)
1981
43.3 C (109.9 F)
1982
42.8 C (109.0 F)
1983
42.2 C (108.0 F)
1984
43.9 C (111.0 F)
1985
41.7 C (107.1 F)
1986
45.6 C (114.1 F)
1987
40.6 C (105.1 F)
1988
42.8 C (109.0 F)
1989
39.4 C (102.9 F)
1990
41.7 C (107.1 F)
1991
40.6 C (105.1 F)
1992
37.2 C (99.0 F)
1993
40.6 C (105.1 F)
1994
40.0 C (104.0 F)
1995
42.2 C (108.0 F)
1996
43.3 C (109.9 F)
1997
37.2 C (99.0 F)
1998
41.7 C (107.1 F)
1999
41.1 C (106.0 F)
2000
42.2 C (108.0 F)
2001
41.1 C (106.0 F)
2002
38.3 C (100.9 F)
2003
41.1 C (106.0 F)
2004
38.3 C (100.9 F)
2005
38.9 C (102.0 F)
2006
42.8 C (109.0 F)
2007
39.4 C (102.9 F)
2008
40.0 C (104.0 F)
2009
41.7 C (107.1 F)
2010
41.7 C (107.1 F)
2011
45.0 C (113.0 F)
2012
43.9 C (111.0 F)
2013
39.4 C (102.9 F)
2014
38.9 C (102.0 F)
2015
38.9 C (102.0 F)
2016
39.4 C (102.9 F)
2017
40.6 C (105.1 F)
2018
37.8 C (100.0 F)
2019
29.4 C (84.9 F)
2020
n/a
2021
n/a
2022
n/a
2023
n/a
2024
n/a
2025
n/a
2026
n/a
Coldest night (TNn)
The coldest night of the year at Blackwell 1SSW, 1953 to 2026. The record is -28.9 C (-20.0 F) in 2011, marked on the chart; the median year is -16.1 C (3.0 F).
Coldest night (TNn) at Blackwell 1SSW by year
Year
Coldest night (TNn)
1953
n/a
1954
-12.2 C (10.0 F)
1955
-13.3 C (8.1 F)
1956
-15.0 C (5.0 F)
1957
-13.9 C (7.0 F)
1958
-21.1 C (-6.0 F)
1959
-21.7 C (-7.1 F)
1960
-17.8 C (0.0 F)
1961
-16.1 C (3.0 F)
1962
-20.6 C (-5.1 F)
1963
-20.6 C (-5.1 F)
1964
-16.1 C (3.0 F)
1965
-15.6 C (3.9 F)
1966
-17.8 C (0.0 F)
1967
-15.6 C (3.9 F)
1968
-17.8 C (0.0 F)
1969
-13.3 C (8.1 F)
1970
-9.4 C (15.1 F)
1971
-16.7 C (1.9 F)
1972
-15.6 C (3.9 F)
1973
-20.6 C (-5.1 F)
1974
-16.7 C (1.9 F)
1975
-15.0 C (5.0 F)
1976
-17.8 C (0.0 F)
1977
-20.6 C (-5.1 F)
1978
-18.9 C (-2.0 F)
1979
-22.2 C (-8.0 F)
1980
-18.9 C (-2.0 F)
1981
-21.1 C (-6.0 F)
1982
-22.2 C (-8.0 F)
1983
-21.1 C (-6.0 F)
1984
-23.3 C (-9.9 F)
1985
-20.0 C (-4.0 F)
1986
-13.3 C (8.1 F)
1987
-16.1 C (3.0 F)
1988
-23.3 C (-9.9 F)
1989
-24.4 C (-11.9 F)
1990
-19.4 C (-2.9 F)
1991
-12.8 C (9.0 F)
1992
-10.6 C (12.9 F)
1993
-16.1 C (3.0 F)
1994
-15.0 C (5.0 F)
1995
-12.8 C (9.0 F)
1996
-16.7 C (1.9 F)
1997
-15.6 C (3.9 F)
1998
-15.0 C (5.0 F)
1999
-13.9 C (7.0 F)
2000
-15.0 C (5.0 F)
2001
-12.8 C (9.0 F)
2002
-16.7 C (1.9 F)
2003
-16.1 C (3.0 F)
2004
-15.0 C (5.0 F)
2005
-16.7 C (1.9 F)
2006
-16.1 C (3.0 F)
2007
-14.4 C (6.1 F)
2008
-14.4 C (6.1 F)
2009
-13.9 C (7.0 F)
2010
-16.7 C (1.9 F)
2011
-28.9 C (-20.0 F)
2012
-12.2 C (10.0 F)
2013
-15.0 C (5.0 F)
2014
-19.4 C (-2.9 F)
2015
-13.9 C (7.0 F)
2016
-21.1 C (-6.0 F)
2017
-14.4 C (6.1 F)
2018
-21.1 C (-6.0 F)
2019
-12.8 C (9.0 F)
2020
n/a
2021
n/a
2022
n/a
2023
n/a
2024
n/a
2025
n/a
2026
n/a
Wettest day (Rx1day)
The wettest day of the year at Blackwell 1SSW, 1953 to 2026. The record is 174.0 mm (6.9 in) in 2009, marked on the chart; the median year is 81.8 mm (3.2 in).
Wettest day (Rx1day) at Blackwell 1SSW by year
Year
Wettest day (Rx1day)
1953
77.2 mm (3.0 in)
1954
46.2 mm (1.8 in)
1955
145.8 mm (5.7 in)
1956
41.9 mm (1.6 in)
1957
39.6 mm (1.6 in)
1958
69.9 mm (2.8 in)
1959
90.7 mm (3.6 in)
1960
95.8 mm (3.8 in)
1961
155.2 mm (6.1 in)
1962
45.0 mm (1.8 in)
1963
95.3 mm (3.8 in)
1964
89.9 mm (3.5 in)
1965
60.2 mm (2.4 in)
1966
55.1 mm (2.2 in)
1967
98.3 mm (3.9 in)
1968
93.5 mm (3.7 in)
1969
135.6 mm (5.3 in)
1970
35.1 mm (1.4 in)
1971
79.0 mm (3.1 in)
1972
67.3 mm (2.6 in)
1973
84.6 mm (3.3 in)
1974
82.8 mm (3.3 in)
1975
84.6 mm (3.3 in)
1976
80.0 mm (3.1 in)
1977
68.6 mm (2.7 in)
1978
40.4 mm (1.6 in)
1979
144.3 mm (5.7 in)
1980
93.0 mm (3.7 in)
1981
49.0 mm (1.9 in)
1982
78.7 mm (3.1 in)
1983
58.9 mm (2.3 in)
1984
83.1 mm (3.3 in)
1985
53.1 mm (2.1 in)
1986
132.3 mm (5.2 in)
1987
91.2 mm (3.6 in)
1988
81.8 mm (3.2 in)
1989
124.5 mm (4.9 in)
1990
34.8 mm (1.4 in)
1991
70.9 mm (2.8 in)
1992
88.9 mm (3.5 in)
1993
62.2 mm (2.4 in)
1994
86.9 mm (3.4 in)
1995
64.8 mm (2.6 in)
1996
139.2 mm (5.5 in)
1997
110.5 mm (4.4 in)
1998
125.2 mm (4.9 in)
1999
82.6 mm (3.3 in)
2000
41.7 mm (1.6 in)
2001
50.0 mm (2.0 in)
2002
90.4 mm (3.6 in)
2003
54.9 mm (2.2 in)
2004
59.2 mm (2.3 in)
2005
63.5 mm (2.5 in)
2006
94.0 mm (3.7 in)
2007
88.4 mm (3.5 in)
2008
85.9 mm (3.4 in)
2009
174.0 mm (6.9 in)
2010
88.9 mm (3.5 in)
2011
84.6 mm (3.3 in)
2012
152.4 mm (6.0 in)
2013
61.2 mm (2.4 in)
2014
57.9 mm (2.3 in)
2015
140.7 mm (5.5 in)
2016
136.4 mm (5.4 in)
2017
76.2 mm (3.0 in)
2018
82.6 mm (3.3 in)
2019
54.6 mm (2.1 in)
2020
81.3 mm (3.2 in)
2021
50.8 mm (2.0 in)
2022
69.9 mm (2.8 in)
2023
66.0 mm (2.6 in)
2024
143.5 mm (5.6 in)
2025
71.1 mm (2.8 in)
2026
81.8 mm (3.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Blackwell 1SSW, 1953 to 2026. The record is 226.0 mm (8.9 in) in 2012, marked on the chart; the median year is 118.3 mm (4.7 in).
Wettest five days (Rx5day) at Blackwell 1SSW by year
Year
Wettest five days (Rx5day)
1953
86.3 mm (3.4 in)
1954
65.0 mm (2.6 in)
1955
194.3 mm (7.6 in)
1956
44.0 mm (1.7 in)
1957
99.6 mm (3.9 in)
1958
143.6 mm (5.7 in)
1959
204.8 mm (8.1 in)
1960
135.7 mm (5.3 in)
1961
155.2 mm (6.1 in)
1962
70.4 mm (2.8 in)
1963
203.7 mm (8.0 in)
1964
164.8 mm (6.5 in)
1965
106.9 mm (4.2 in)
1966
81.8 mm (3.2 in)
1967
112.0 mm (4.4 in)
1968
109.2 mm (4.3 in)
1969
136.9 mm (5.4 in)
1970
45.0 mm (1.8 in)
1971
113.3 mm (4.5 in)
1972
71.6 mm (2.8 in)
1973
95.0 mm (3.7 in)
1974
145.2 mm (5.7 in)
1975
103.1 mm (4.1 in)
1976
103.3 mm (4.1 in)
1977
110.0 mm (4.3 in)
1978
53.4 mm (2.1 in)
1979
164.6 mm (6.5 in)
1980
133.9 mm (5.3 in)
1981
90.1 mm (3.5 in)
1982
134.6 mm (5.3 in)
1983
107.2 mm (4.2 in)
1984
101.6 mm (4.0 in)
1985
110.6 mm (4.4 in)
1986
223.7 mm (8.8 in)
1987
214.4 mm (8.4 in)
1988
119.5 mm (4.7 in)
1989
144.8 mm (5.7 in)
1990
67.3 mm (2.6 in)
1991
122.2 mm (4.8 in)
1992
91.9 mm (3.6 in)
1993
149.3 mm (5.9 in)
1994
127.0 mm (5.0 in)
1995
179.1 mm (7.1 in)
1996
142.8 mm (5.6 in)
1997
189.9 mm (7.5 in)
1998
187.7 mm (7.4 in)
1999
132.1 mm (5.2 in)
2000
72.5 mm (2.9 in)
2001
61.8 mm (2.4 in)
2002
141.7 mm (5.6 in)
2003
84.7 mm (3.3 in)
2004
108.9 mm (4.3 in)
2005
100.4 mm (4.0 in)
2006
118.1 mm (4.6 in)
2007
188.5 mm (7.4 in)
2008
120.4 mm (4.7 in)
2009
216.1 mm (8.5 in)
2010
131.6 mm (5.2 in)
2011
97.1 mm (3.8 in)
2012
226.0 mm (8.9 in)
2013
65.0 mm (2.6 in)
2014
113.6 mm (4.5 in)
2015
184.9 mm (7.3 in)
2016
163.3 mm (6.4 in)
2017
84.8 mm (3.3 in)
2018
140.0 mm (5.5 in)
2019
75.4 mm (3.0 in)
2020
118.4 mm (4.7 in)
2021
91.2 mm (3.6 in)
2022
90.7 mm (3.6 in)
2023
84.8 mm (3.3 in)
2024
150.9 mm (5.9 in)
2025
121.9 mm (4.8 in)
2026
180.3 mm (7.1 in)
Longest dry spell (CDD)
The longest dry spell of the year at Blackwell 1SSW, 1953 to 2026. The record is 64 days in 1966, marked on the chart; the median year is 30 days.
Longest dry spell (CDD) at Blackwell 1SSW by year
Year
Longest dry spell (CDD)
1953
27 days
1954
62 days
1955
56 days
1956
37 days
1957
24 days
1958
20 days
1959
39 days
1960
27 days
1961
35 days
1962
30 days
1963
57 days
1964
30 days
1965
43 days
1966
64 days
1967
25 days
1968
18 days
1969
18 days
1970
15 days
1971
31 days
1972
37 days
1973
21 days
1974
25 days
1975
28 days
1976
62 days
1977
52 days
1978
34 days
1979
38 days
1980
42 days
1981
31 days
1982
29 days
1983
30 days
1984
23 days
1985
46 days
1986
38 days
1987
21 days
1988
54 days
1989
39 days
1990
28 days
1991
40 days
1992
20 days
1993
26 days
1994
26 days
1995
30 days
1996
41 days
1997
24 days
1998
27 days
1999
31 days
2000
37 days
2001
24 days
2002
30 days
2003
32 days
2004
24 days
2005
30 days
2006
40 days
2007
38 days
2008
20 days
2009
39 days
2010
35 days
2011
19 days
2012
28 days
2013
30 days
2014
30 days
2015
28 days
2016
35 days
2017
37 days
2018
21 days
2019
28 days
2020
28 days
2021
34 days
2022
32 days
2023
20 days
2024
34 days
2025
40 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
53 years with a frost
Across 53 years with a frost, the median last spring frost at Blackwell 1SSW falls on 6 April and the median first autumn frost on 28 October, which leaves a median of 205 days between them.
Fitted over all years, the growing season changes by +3.0 days per decade at this station.
Frost dates and growing season at Blackwell 1SSW
Measure
Median, all years
Earliest period
Recent period (1984 to 2018)
Recent against earliest
Fitted trend
Last spring frost
6 April
n/a
5 April
n/a
-1.2 days per decade
First autumn frost
28 October
n/a
2 November
n/a
+1.7 days per decade
Growing days
205 days
n/a
212 days
n/a
+3.0 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
67 years, 1954 to 2025
A day with at least 80.0 mm (3.1 in) of rain is expected about once in 2 years. A day with at least 188.7 mm (7.4 in) of rain is expected about once in 100 years.
Rainfall return levels at Blackwell 1SSW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
80.0 mm (3.1 in)
5 years
108.8 mm (4.3 in)
10 years
128.0 mm (5.0 in)
25 years
152.4 mm (6.0 in)
50 years
170.6 mm (6.7 in)
100 years
188.7 mm (7.4 in)
Longer than the 67 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, 67 years of values from 1954 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: 174.0 mm (6.9 in) in 2009; 155.2 mm (6.1 in) in 1961; 152.4 mm (6.0 in) in 2012.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Climate Twins
2004 to 2018 against 1961 to 1990
Over 2004 to 2018, Blackwell 1SSW had a mean temperature of 15.0 C (59.0 F) and 919.6 mm (36.2 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Cushing (United States, 100 km away), Nowata (United States, 147 km away) and Claremore 2 ENE (United States, 161 km away).
Climate twins of Blackwell 1SSW: stations whose 1961 to 1990 climate is closest to its 2004 to 2018 climate
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Data for Blackwell 1SSW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Blackwell 1SSW 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.