Record envelope, standing records and threshold days for Colebrook 3SW (USC00271647), New Hampshire, United States, with 67 years of record.
Key Facts for Colebrook 3SW
Colebrook 3SW (USC00271647) is a weather station in New Hampshire, United States at 44.86 latitude and -71.54 longitude, 341 m (1,120 ft) above sea level.
The station reports from 1960 to 2026, 67 years of record.
1,464 records set at Colebrook 3SW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Colebrook 3SW tied a daily record high maximum temperature of 30.0 C (86.0 F) on 8 August 2026.
About the Station
Location: New Hampshire, United States, 44.86 latitude, -71.54 longitude.
Elevation: 341 m (1,120 ft).
Period of record: 1960 to 2026, 67 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
5 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 Colebrook 3SW. The lines show the 2026 daily maximum and minimum. 5 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Colebrook 3SW, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
16.1 C (61.0 F)
-40.0 C (-40.0 F)
5.6 C (42.1 F)
-32.2 C (-26.0 F)
Feb
17.2 C (63.0 F)
-41.1 C (-42.0 F)
5.6 C (42.1 F)
-29.4 C (-20.9 F)
Mar
26.1 C (79.0 F)
-33.9 C (-29.0 F)
19.4 C (66.9 F)
-27.2 C (-17.0 F)
Apr
30.0 C (86.0 F)
-22.2 C (-8.0 F)
22.2 C (72.0 F)
-12.2 C (10.0 F)
May
32.8 C (91.0 F)
-8.3 C (17.1 F)
27.2 C (81.0 F)
-3.9 C (25.0 F)
Jun
34.4 C (93.9 F)
-2.8 C (27.0 F)
31.1 C (88.0 F)
1.1 C (34.0 F)
Jul
34.4 C (93.9 F)
-0.6 C (30.9 F)
31.1 C (88.0 F)
6.1 C (43.0 F)
Aug
35.0 C (95.0 F)
-1.7 C (28.9 F)
30.0 C (86.0 F)
5.6 C (42.1 F)
Sep
34.4 C (93.9 F)
-7.8 C (18.0 F)
24.4 C (75.9 F)
-1.1 C (30.0 F)
Oct
28.3 C (82.9 F)
-13.9 C (7.0 F)
22.2 C (72.0 F)
-2.8 C (27.0 F)
Nov
22.8 C (73.0 F)
-25.0 C (-13.0 F)
n/a
n/a
Dec
18.3 C (64.9 F)
-38.9 C (-38.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Colebrook 3SW still stand. 1979 holds the most, with 54.
Standing records at Colebrook 3SW by the year they were set
Year set
Standing records
1960
6
1961
30
1962
19
1963
16
1964
32
1965
12
1966
3
1967
12
1968
39
1969
27
1970
40
1971
34
1972
27
1973
25
1974
24
1975
20
1976
31
1977
23
1978
25
1979
54
1980
24
1981
21
1982
19
1983
12
1984
27
1985
12
1986
18
1987
29
1988
36
1989
41
1990
27
1991
17
1992
23
1993
23
1994
20
1995
13
1996
25
1997
8
1998
17
1999
27
2000
23
2001
27
2002
34
2003
30
2004
17
2005
24
2006
11
2007
20
2008
14
2009
10
2010
15
2011
10
2012
22
2013
14
2014
25
2015
24
2016
16
2017
33
2018
24
2019
16
2020
20
2021
21
2022
20
2023
17
2024
14
2025
20
2026
5
All-Time Record Progression
5 new records
5 all-time records were set at Colebrook 3SW between 7 July 1995 and 1 October 2010. Each dot is a new record.
When Colebrook 3SW set new all-time records
Date
Kind
Detail
1995-07-07
Record high minimum temperature
Record high minimum temperature 21.7 C (71.1 F)
1999-08-01
Record high minimum temperature
Record high minimum temperature 22.2 C (72.0 F)
2003-12-07
Record daily snowfall
Record daily snowfall 45.7 cm (18.0 in)
2004-01-15
Record low maximum temperature
Record low maximum temperature -25.0 C (-13.0 F)
2010-10-01
Record daily precipitation
Record daily precipitation 91.7 mm (3.6 in)
Wettest Day of Each Month
Oct: 91.7 mm (3.6 in)
The wettest day on record for each calendar month at Colebrook 3SW. The most was 91.7 mm (3.6 in) on 1 October 2010.
Record daily precipitation for each month at Colebrook 3SW
Month
Record daily precipitation (mm)
Date
Jan
49.5 mm (1.9 in)
28 January 1994
Feb
44.5 mm (1.8 in)
25 February 2016
Mar
38.4 mm (1.5 in)
7 March 2011
Apr
39.9 mm (1.6 in)
19 April 1969
May
71.1 mm (2.8 in)
19 May 1999
Jun
87.6 mm (3.4 in)
9 June 1978
Jul
71.1 mm (2.8 in)
20 July 2015
Aug
86.9 mm (3.4 in)
4 August 2010
Sep
74.9 mm (2.9 in)
5 September 2012
Oct
91.7 mm (3.6 in)
1 October 2010
Nov
51.3 mm (2.0 in)
28 November 2009
Dec
85.6 mm (3.4 in)
12 December 2024
Period of Record Coverage
1960 to 2026
Complete yearUnder 90 percent of days
67 years of record at Colebrook 3SW, 1960 to 2026. 11 years have data for under 90 percent of days and are left out of rankings: 1960, 1963, 1965, 1966, 1967, 1982, 1983, 2006 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 53 complete years at Colebrook 3SW, 1961 to 2024. Blue stripes are years cooler than the station's own mean of 4.8 C (40.6 F); red stripes are warmer. The coolest year was 2019, at 3.4 C (38.0 F), and the warmest was 1998, at 6.9 C (44.3 F). The strongest colour marks a difference of 2.1 C (3.8 F).
Annual mean temperature at Colebrook 3SW as warming stripes, 1961 to 2024
Year
Annual mean temperature
Difference from the station mean
1961
5.6 C
+0.78 C
1964
5.0 C
+0.22 C
1968
3.6 C
-1.16 C
1969
4.4 C
-0.38 C
1970
4.1 C
-0.69 C
1972
3.9 C
-0.91 C
1973
5.7 C
+0.92 C
1974
4.2 C
-0.60 C
1975
4.9 C
+0.14 C
1976
4.0 C
-0.82 C
1977
4.5 C
-0.27 C
1978
3.6 C
-1.22 C
1979
5.2 C
+0.36 C
1980
3.9 C
-0.91 C
1981
5.2 C
+0.39 C
1984
5.6 C
+0.78 C
1985
4.5 C
-0.29 C
1986
4.9 C
+0.13 C
1987
5.0 C
+0.24 C
1988
4.3 C
-0.53 C
1989
3.8 C
-0.95 C
1990
6.1 C
+1.27 C
1991
5.4 C
+0.63 C
1992
4.1 C
-0.66 C
1993
4.6 C
-0.22 C
1996
5.1 C
+0.30 C
1997
4.4 C
-0.39 C
1998
6.9 C
+2.06 C
1999
6.5 C
+1.72 C
2000
4.7 C
-0.05 C
2001
5.5 C
+0.68 C
2002
5.4 C
+0.61 C
2003
4.4 C
-0.40 C
2004
4.5 C
-0.25 C
2005
5.4 C
+0.56 C
2007
3.8 C
-0.98 C
2008
4.7 C
-0.10 C
2009
4.0 C
-0.75 C
2010
5.6 C
+0.85 C
2011
4.9 C
+0.15 C
2012
5.9 C
+1.12 C
2013
4.7 C
-0.14 C
2014
3.9 C
-0.86 C
2015
3.7 C
-1.12 C
2016
5.2 C
+0.40 C
2017
4.7 C
-0.08 C
2018
4.3 C
-0.50 C
2019
3.4 C
-1.43 C
2020
4.8 C
+0.03 C
2021
4.5 C
-0.31 C
2022
4.8 C
-0.04 C
2023
6.0 C
+1.16 C
2024
6.2 C
+1.40 C
The fitted trend in annual mean temperature here over 1961 to 2024 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 (-0.1 to 0.3) 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 Colebrook 3SW
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 (-0.1 to 0.3) per decade
1961 to 2024
53
Not clearly different from zero
Mean daily maximum
-0.02 C (-0.12 to 0.09) per decade
-0.03 F (-0.22 to 0.16) per decade
1961 to 2024
53
Not clearly different from zero
Mean daily minimum
0.12 C (-0.03 to 0.28) per decade
0.2 F (-0.1 to 0.5) per decade
1961 to 2024
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
1960 to 2026
Yearly extremes at Colebrook 3SW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
35.0 C (95.0 F)
1975
31.7 C (89.1 F)
67
Coldest night (TNn)
-41.1 C (-42.0 F)
1962
-33.9 C (-29.0 F)
67
Wettest day (Rx1day)
91.7 mm (3.6 in)
2010
46.7 mm (1.8 in)
67
Wettest five days (Rx5day)
140.4 mm (5.5 in)
2010
75.0 mm (3.0 in)
67
Longest dry spell (CDD)
34 days
1978
14 days
67
Hottest day (TXx)
The hottest day of the year at Colebrook 3SW, 1960 to 2026. The record is 35.0 C (95.0 F) in 1975, marked on the chart; the median year is 31.7 C (89.1 F).
Hottest day (TXx) at Colebrook 3SW by year
Year
Hottest day (TXx)
1960
31.7 C (89.1 F)
1961
31.7 C (89.1 F)
1962
30.6 C (87.1 F)
1963
26.7 C (80.1 F)
1964
31.7 C (89.1 F)
1965
31.7 C (89.1 F)
1966
11.7 C (53.1 F)
1967
26.1 C (79.0 F)
1968
31.1 C (88.0 F)
1969
32.2 C (90.0 F)
1970
31.1 C (88.0 F)
1971
32.2 C (90.0 F)
1972
33.9 C (93.0 F)
1973
33.3 C (91.9 F)
1974
30.0 C (86.0 F)
1975
35.0 C (95.0 F)
1976
31.1 C (88.0 F)
1977
33.3 C (91.9 F)
1978
31.7 C (89.1 F)
1979
34.4 C (93.9 F)
1980
31.1 C (88.0 F)
1981
32.2 C (90.0 F)
1982
31.7 C (89.1 F)
1983
30.6 C (87.1 F)
1984
33.3 C (91.9 F)
1985
30.0 C (86.0 F)
1986
30.6 C (87.1 F)
1987
32.8 C (91.0 F)
1988
33.9 C (93.0 F)
1989
32.2 C (90.0 F)
1990
30.0 C (86.0 F)
1991
32.2 C (90.0 F)
1992
30.0 C (86.0 F)
1993
32.8 C (91.0 F)
1994
32.8 C (91.0 F)
1995
33.9 C (93.0 F)
1996
30.6 C (87.1 F)
1997
29.4 C (84.9 F)
1998
31.1 C (88.0 F)
1999
34.4 C (93.9 F)
2000
31.1 C (88.0 F)
2001
33.9 C (93.0 F)
2002
34.4 C (93.9 F)
2003
34.4 C (93.9 F)
2004
30.0 C (86.0 F)
2005
32.8 C (91.0 F)
2006
22.2 C (72.0 F)
2007
31.1 C (88.0 F)
2008
31.1 C (88.0 F)
2009
30.0 C (86.0 F)
2010
32.8 C (91.0 F)
2011
31.1 C (88.0 F)
2012
31.7 C (89.1 F)
2013
31.7 C (89.1 F)
2014
31.1 C (88.0 F)
2015
30.6 C (87.1 F)
2016
30.0 C (86.0 F)
2017
31.1 C (88.0 F)
2018
32.2 C (90.0 F)
2019
30.6 C (87.1 F)
2020
32.8 C (91.0 F)
2021
33.3 C (91.9 F)
2022
30.0 C (86.0 F)
2023
31.7 C (89.1 F)
2024
31.7 C (89.1 F)
2025
32.2 C (90.0 F)
2026
31.1 C (88.0 F)
Coldest night (TNn)
The coldest night of the year at Colebrook 3SW, 1960 to 2026. The record is -41.1 C (-42.0 F) in 1962, marked on the chart; the median year is -33.9 C (-29.0 F).
Coldest night (TNn) at Colebrook 3SW by year
Year
Coldest night (TNn)
1960
-30.6 C (-23.1 F)
1961
-36.1 C (-33.0 F)
1962
-41.1 C (-42.0 F)
1963
-36.1 C (-33.0 F)
1964
-32.8 C (-27.0 F)
1965
-33.9 C (-29.0 F)
1966
-31.1 C (-24.0 F)
1967
-27.8 C (-18.0 F)
1968
-40.0 C (-40.0 F)
1969
-35.0 C (-31.0 F)
1970
-35.6 C (-32.1 F)
1971
-38.9 C (-38.0 F)
1972
-38.9 C (-38.0 F)
1973
-38.9 C (-38.0 F)
1974
-37.2 C (-35.0 F)
1975
-35.0 C (-31.0 F)
1976
-38.9 C (-38.0 F)
1977
-33.3 C (-27.9 F)
1978
-36.1 C (-33.0 F)
1979
-40.0 C (-40.0 F)
1980
-38.9 C (-38.0 F)
1981
-38.3 C (-36.9 F)
1982
-37.2 C (-35.0 F)
1983
-31.1 C (-24.0 F)
1984
-36.7 C (-34.1 F)
1985
-35.0 C (-31.0 F)
1986
-31.7 C (-25.1 F)
1987
-36.1 C (-33.0 F)
1988
-33.9 C (-29.0 F)
1989
-36.1 C (-33.0 F)
1990
-27.8 C (-18.0 F)
1991
-31.7 C (-25.1 F)
1992
-32.8 C (-27.0 F)
1993
-39.4 C (-38.9 F)
1994
-38.3 C (-36.9 F)
1995
-30.0 C (-22.0 F)
1996
-35.6 C (-32.1 F)
1997
-33.9 C (-29.0 F)
1998
-30.6 C (-23.1 F)
1999
-36.7 C (-34.1 F)
2000
-33.3 C (-27.9 F)
2001
-27.8 C (-18.0 F)
2002
-27.2 C (-17.0 F)
2003
-36.7 C (-34.1 F)
2004
-37.8 C (-36.0 F)
2005
-32.2 C (-26.0 F)
2006
-24.4 C (-11.9 F)
2007
-32.8 C (-27.0 F)
2008
-32.8 C (-27.0 F)
2009
-36.1 C (-33.0 F)
2010
-28.3 C (-18.9 F)
2011
-33.3 C (-27.9 F)
2012
-28.9 C (-20.0 F)
2013
-32.8 C (-27.0 F)
2014
-31.1 C (-24.0 F)
2015
-34.4 C (-29.9 F)
2016
-30.0 C (-22.0 F)
2017
-30.6 C (-23.1 F)
2018
-35.0 C (-31.0 F)
2019
-27.8 C (-18.0 F)
2020
-34.4 C (-29.9 F)
2021
-29.4 C (-20.9 F)
2022
-33.9 C (-29.0 F)
2023
-31.1 C (-24.0 F)
2024
-25.6 C (-14.1 F)
2025
-31.7 C (-25.1 F)
2026
-32.2 C (-26.0 F)
Wettest day (Rx1day)
The wettest day of the year at Colebrook 3SW, 1960 to 2026. The record is 91.7 mm (3.6 in) in 2010, marked on the chart; the median year is 46.7 mm (1.8 in).
Wettest day (Rx1day) at Colebrook 3SW by year
Year
Wettest day (Rx1day)
1960
38.6 mm (1.5 in)
1961
47.0 mm (1.9 in)
1962
50.8 mm (2.0 in)
1963
20.3 mm (0.8 in)
1964
39.9 mm (1.6 in)
1965
48.3 mm (1.9 in)
1966
38.1 mm (1.5 in)
1967
36.3 mm (1.4 in)
1968
35.1 mm (1.4 in)
1969
64.3 mm (2.5 in)
1970
44.2 mm (1.7 in)
1971
33.8 mm (1.3 in)
1972
29.0 mm (1.1 in)
1973
76.2 mm (3.0 in)
1974
32.5 mm (1.3 in)
1975
48.0 mm (1.9 in)
1976
57.2 mm (2.3 in)
1977
70.4 mm (2.8 in)
1978
87.6 mm (3.4 in)
1979
40.6 mm (1.6 in)
1980
27.2 mm (1.1 in)
1981
56.4 mm (2.2 in)
1982
37.6 mm (1.5 in)
1983
45.7 mm (1.8 in)
1984
46.2 mm (1.8 in)
1985
37.6 mm (1.5 in)
1986
50.8 mm (2.0 in)
1987
48.3 mm (1.9 in)
1988
46.2 mm (1.8 in)
1989
38.1 mm (1.5 in)
1990
47.8 mm (1.9 in)
1991
63.8 mm (2.5 in)
1992
35.8 mm (1.4 in)
1993
49.8 mm (2.0 in)
1994
49.5 mm (1.9 in)
1995
46.2 mm (1.8 in)
1996
36.8 mm (1.4 in)
1997
63.5 mm (2.5 in)
1998
58.4 mm (2.3 in)
1999
71.1 mm (2.8 in)
2000
61.0 mm (2.4 in)
2001
48.3 mm (1.9 in)
2002
55.9 mm (2.2 in)
2003
53.3 mm (2.1 in)
2004
43.7 mm (1.7 in)
2005
64.8 mm (2.6 in)
2006
47.8 mm (1.9 in)
2007
45.7 mm (1.8 in)
2008
46.0 mm (1.8 in)
2009
51.3 mm (2.0 in)
2010
91.7 mm (3.6 in)
2011
69.3 mm (2.7 in)
2012
74.9 mm (2.9 in)
2013
59.2 mm (2.3 in)
2014
34.8 mm (1.4 in)
2015
71.1 mm (2.8 in)
2016
44.5 mm (1.8 in)
2017
43.7 mm (1.7 in)
2018
30.2 mm (1.2 in)
2019
36.8 mm (1.4 in)
2020
46.7 mm (1.8 in)
2021
43.7 mm (1.7 in)
2022
54.6 mm (2.1 in)
2023
41.9 mm (1.6 in)
2024
85.6 mm (3.4 in)
2025
30.2 mm (1.2 in)
2026
39.4 mm (1.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Colebrook 3SW, 1960 to 2026. The record is 140.4 mm (5.5 in) in 2010, marked on the chart; the median year is 75.0 mm (3.0 in).
Wettest five days (Rx5day) at Colebrook 3SW by year
Year
Wettest five days (Rx5day)
1960
86.4 mm (3.4 in)
1961
54.6 mm (2.1 in)
1962
72.4 mm (2.9 in)
1963
45.7 mm (1.8 in)
1964
60.5 mm (2.4 in)
1965
68.3 mm (2.7 in)
1966
45.8 mm (1.8 in)
1967
37.9 mm (1.5 in)
1968
47.9 mm (1.9 in)
1969
94.6 mm (3.7 in)
1970
58.0 mm (2.3 in)
1971
65.7 mm (2.6 in)
1972
55.4 mm (2.2 in)
1973
109.9 mm (4.3 in)
1974
77.9 mm (3.1 in)
1975
69.7 mm (2.7 in)
1976
85.6 mm (3.4 in)
1977
74.5 mm (2.9 in)
1978
115.8 mm (4.6 in)
1979
69.8 mm (2.7 in)
1980
56.9 mm (2.2 in)
1981
83.4 mm (3.3 in)
1982
56.1 mm (2.2 in)
1983
63.8 mm (2.5 in)
1984
127.5 mm (5.0 in)
1985
66.8 mm (2.6 in)
1986
76.7 mm (3.0 in)
1987
92.0 mm (3.6 in)
1988
75.0 mm (3.0 in)
1989
85.4 mm (3.4 in)
1990
96.5 mm (3.8 in)
1991
84.3 mm (3.3 in)
1992
74.9 mm (2.9 in)
1993
99.6 mm (3.9 in)
1994
54.3 mm (2.1 in)
1995
60.9 mm (2.4 in)
1996
76.4 mm (3.0 in)
1997
69.9 mm (2.8 in)
1998
91.2 mm (3.6 in)
1999
87.6 mm (3.4 in)
2000
97.2 mm (3.8 in)
2001
50.8 mm (2.0 in)
2002
76.2 mm (3.0 in)
2003
90.9 mm (3.6 in)
2004
55.2 mm (2.2 in)
2005
132.1 mm (5.2 in)
2006
63.3 mm (2.5 in)
2007
74.4 mm (2.9 in)
2008
91.6 mm (3.6 in)
2009
87.3 mm (3.4 in)
2010
140.4 mm (5.5 in)
2011
80.0 mm (3.1 in)
2012
81.5 mm (3.2 in)
2013
129.0 mm (5.1 in)
2014
72.2 mm (2.8 in)
2015
98.6 mm (3.9 in)
2016
59.5 mm (2.3 in)
2017
92.5 mm (3.6 in)
2018
60.5 mm (2.4 in)
2019
63.5 mm (2.5 in)
2020
84.3 mm (3.3 in)
2021
62.5 mm (2.5 in)
2022
99.7 mm (3.9 in)
2023
72.4 mm (2.9 in)
2024
94.2 mm (3.7 in)
2025
48.6 mm (1.9 in)
2026
75.9 mm (3.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Colebrook 3SW, 1960 to 2026. The record is 34 days in 1978, marked on the chart; the median year is 14 days.
Longest dry spell (CDD) at Colebrook 3SW by year
Year
Longest dry spell (CDD)
1960
9 days
1961
13 days
1962
10 days
1963
14 days
1964
17 days
1965
11 days
1966
21 days
1967
11 days
1968
12 days
1969
14 days
1970
17 days
1971
12 days
1972
11 days
1973
17 days
1974
11 days
1975
12 days
1976
19 days
1977
15 days
1978
34 days
1979
13 days
1980
19 days
1981
12 days
1982
14 days
1983
9 days
1984
12 days
1985
16 days
1986
22 days
1987
21 days
1988
15 days
1989
17 days
1990
12 days
1991
26 days
1992
20 days
1993
15 days
1994
20 days
1995
22 days
1996
23 days
1997
18 days
1998
18 days
1999
20 days
2000
11 days
2001
20 days
2002
12 days
2003
17 days
2004
24 days
2005
15 days
2006
12 days
2007
14 days
2008
16 days
2009
14 days
2010
22 days
2011
10 days
2012
12 days
2013
14 days
2014
16 days
2015
10 days
2016
8 days
2017
18 days
2018
11 days
2019
9 days
2020
15 days
2021
17 days
2022
10 days
2023
17 days
2024
10 days
2025
12 days
2026
10 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 Colebrook 3SW falls on 1 June and the median first autumn frost on 16 September, which leaves a median of 106 days between them.
Fitted over all years, the growing season changes by +11.5 days per decade at this station.
Frost dates and growing season at Colebrook 3SW
Measure
Median, all years
Earliest period
Recent period (1992 to 2024)
Recent against earliest
Fitted trend
Last spring frost
1 June
n/a
28 May
n/a
-3.6 days per decade
First autumn frost
16 September
n/a
22 September
n/a
+7.9 days per decade
Growing days
106 days
n/a
118 days
n/a
+11.5 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
44 years, 1961 to 2020
A day with at least 48.6 mm (1.9 in) of rain is expected about once in 2 years. A day with at least 95.5 mm (3.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Colebrook 3SW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
48.6 mm (1.9 in)
5 years
61.2 mm (2.4 in)
10 years
69.6 mm (2.7 in)
25 years
80.1 mm (3.2 in)
50 years
87.9 mm (3.5 in)
Longer than the 44 years of record
100 years
95.5 mm (3.8 in)
Longer than the 44 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, 44 years of values from 1961 to 2020.
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: 91.7 mm (3.6 in) in 2010; 87.6 mm (3.4 in) in 1978; 76.2 mm (3.0 in) in 1973.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Colebrook 3SW, at 2007. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 2007 ran 0.4 C (0.7 F) lower than in the years before (possible change).
Suspected changes in the annual mean temperature at Colebrook 3SW, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
2007
-0.4
-0.7
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 Colebrook 3SW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Colebrook 3SW 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.