Record envelope, standing records and threshold days for Terry 21 NNW (USC00248169), Montana, United States, with 70 years of record.
Key Facts for Terry 21 NNW
Terry 21 NNW (USC00248169) is a weather station in Montana, United States at 47.07 latitude and -105.50 longitude, 958 m (3,142 ft) above sea level.
The station reports from 1949 to 2018, 70 years of record.
1,464 records set at Terry 21 NNW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Terry 21 NNW set a daily record precipitation of 28.4 mm (1.1 in) on 20 September 2018.
About the Station
Location: Montana, United States, 47.07 latitude, -105.50 longitude.
Elevation: 958 m (3,142 ft).
Period of record: 1949 to 2018, 70 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 Terry 21 NNW. 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 Terry 21 NNW, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
18.3 C (64.9 F)
-37.8 C (-36.0 F)
n/a
n/a
Feb
19.4 C (66.9 F)
-36.1 C (-33.0 F)
n/a
n/a
Mar
25.6 C (78.1 F)
-36.7 C (-34.1 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-22.2 C (-8.0 F)
n/a
n/a
May
35.6 C (96.1 F)
-11.7 C (10.9 F)
n/a
n/a
Jun
39.4 C (102.9 F)
-4.4 C (24.1 F)
n/a
n/a
Jul
40.0 C (104.0 F)
1.1 C (34.0 F)
n/a
n/a
Aug
38.9 C (102.0 F)
-2.2 C (28.0 F)
n/a
n/a
Sep
37.2 C (99.0 F)
-10.0 C (14.0 F)
n/a
n/a
Oct
31.7 C (89.1 F)
-25.6 C (-14.1 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-32.2 C (-26.0 F)
n/a
n/a
Dec
18.9 C (66.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Terry 21 NNW still stand. 1992 holds the most, with 55.
Standing records at Terry 21 NNW by the year they were set
Year set
Standing records
1962
11
1963
44
1964
30
1965
46
1966
34
1967
26
1968
22
1969
43
1970
20
1971
22
1972
40
1973
18
1974
25
1975
19
1976
17
1977
23
1978
21
1979
26
1980
28
1981
21
1982
27
1983
29
1984
29
1985
51
1986
36
1987
35
1988
53
1989
32
1990
26
1991
43
1992
55
1993
30
1994
18
1995
31
1996
34
1997
32
1998
21
1999
31
2000
28
2001
14
2002
44
2003
40
2004
24
2005
24
2006
24
2007
24
2008
12
2009
31
2010
6
2011
13
2012
15
2013
8
2015
3
2018
5
All-Time Record Progression
3 new records
3 all-time records were set at Terry 21 NNW between 18 April 1992 and 23 July 2007. Each dot is a new record.
When Terry 21 NNW set new all-time records
Date
Kind
Detail
1992-04-18
Record daily precipitation
Record daily precipitation 98.0 mm (3.9 in)
1997-07-01
Record daily precipitation
Record daily precipitation 118.9 mm (4.7 in)
2007-07-23
Record high maximum temperature
Record high maximum temperature 40.0 C (104.0 F)
Wettest Day of Each Month
Jul: 118.9 mm (4.7 in)
The wettest day on record for each calendar month at Terry 21 NNW. The most was 118.9 mm (4.7 in) on 1 July 1997.
Record daily precipitation for each month at Terry 21 NNW
Month
Record daily precipitation (mm)
Date
Jan
14.2 mm (0.6 in)
6 January 1980
Feb
13.7 mm (0.5 in)
12 February 1965
Mar
20.6 mm (0.8 in)
12 March 1995
Apr
98.0 mm (3.9 in)
18 April 1992
May
50.8 mm (2.0 in)
25 May 2010
Jun
93.2 mm (3.7 in)
18 June 1973
Jul
118.9 mm (4.7 in)
1 July 1997
Aug
65.0 mm (2.6 in)
5 August 2011
Sep
76.7 mm (3.0 in)
25 September 1986
Oct
37.1 mm (1.5 in)
22 October 1980
Nov
18.3 mm (0.7 in)
2 November 2000
Dec
13.5 mm (0.5 in)
9 December 1989
Period of Record Coverage
1962 to 2018
Complete yearUnder 90 percent of days
55 years of record at Terry 21 NNW, 1962 to 2018. 8 years have data for under 90 percent of days and are left out of rankings: 1962, 2010, 2011, 2012, 2013, 2014, 2015, 2018.
Cooler than the station meanWarmer than the station mean
One stripe for each of 44 complete years at Terry 21 NNW, 1963 to 2009. Blue stripes are years cooler than the station's own mean of 5.7 C (42.2 F); red stripes are warmer. The coolest year was 1996, at 3.5 C (38.3 F), and the warmest was 1987, at 7.8 C (46.0 F). The strongest colour marks a difference of 2.2 C (4.0 F).
Annual mean temperature at Terry 21 NNW as warming stripes, 1963 to 2009
Year
Annual mean temperature
Difference from the station mean
1963
7.0 C
+1.34 C
1964
5.9 C
+0.19 C
1965
4.8 C
-0.87 C
1967
5.3 C
-0.35 C
1968
5.2 C
-0.49 C
1969
4.7 C
-0.99 C
1970
4.7 C
-0.99 C
1971
4.9 C
-0.75 C
1972
4.1 C
-1.58 C
1973
6.4 C
+0.68 C
1974
6.2 C
+0.49 C
1976
6.5 C
+0.85 C
1977
5.9 C
+0.20 C
1978
3.9 C
-1.74 C
1979
4.7 C
-0.94 C
1981
7.3 C
+1.65 C
1982
4.2 C
-1.48 C
1983
5.9 C
+0.20 C
1984
6.0 C
+0.32 C
1985
4.5 C
-1.16 C
1986
6.6 C
+0.88 C
1987
7.8 C
+2.07 C
1988
7.4 C
+1.75 C
1989
5.3 C
-0.40 C
1990
7.0 C
+1.33 C
1991
6.9 C
+1.24 C
1992
6.5 C
+0.83 C
1993
4.0 C
-1.67 C
1994
5.4 C
-0.24 C
1995
5.5 C
-0.19 C
1996
3.5 C
-2.20 C
1997
6.0 C
+0.29 C
1998
6.6 C
+0.90 C
1999
6.7 C
+1.03 C
2000
5.5 C
-0.17 C
2001
6.2 C
+0.53 C
2002
5.1 C
-0.61 C
2003
6.0 C
+0.32 C
2004
5.6 C
-0.10 C
2005
6.0 C
+0.29 C
2006
6.7 C
+1.06 C
2007
6.4 C
+0.69 C
2008
4.5 C
-1.21 C
2009
4.6 C
-1.12 C
The fitted trend in annual mean temperature here over 1963 to 2009 is 0.1 C (-0.2 to 0.3) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.3 to 0.6) per decade. The slope is a straight line fitted to 44 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Terry 21 NNW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (-0.2 to 0.3) per decade
0.1 F (-0.3 to 0.6) per decade
1963 to 2009
44
Not clearly different from zero
Mean daily maximum
0.2 C (-0.1 to 0.4) per decade
0.3 F (-0.2 to 0.8) per decade
1963 to 2009
44
Not clearly different from zero
Mean daily minimum
-0.01 C (-0.23 to 0.21) per decade
-0.02 F (-0.42 to 0.37) per decade
1963 to 2009
44
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
1949 to 2018
Yearly extremes at Terry 21 NNW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
2007
36.7 C (98.1 F)
55
Coldest night (TNn)
-38.3 C (-36.9 F)
1989
-33.3 C (-27.9 F)
55
Wettest day (Rx1day)
118.9 mm (4.7 in)
1997
33.2 mm (1.3 in)
58
Wettest five days (Rx5day)
130.2 mm (5.1 in)
1992
52.8 mm (2.1 in)
56
Longest dry spell (CDD)
78 days
1963
34 days
58
Hottest day (TXx)
The hottest day of the year at Terry 21 NNW, 1949 to 2018. The record is 40.0 C (104.0 F) in 2007, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Terry 21 NNW by year
Year
Hottest day (TXx)
1949
n/a
1950
n/a
1951
n/a
1962
34.4 C (93.9 F)
1963
36.1 C (97.0 F)
1964
37.8 C (100.0 F)
1965
37.8 C (100.0 F)
1966
39.4 C (102.9 F)
1967
35.6 C (96.1 F)
1968
34.4 C (93.9 F)
1969
36.7 C (98.1 F)
1970
36.7 C (98.1 F)
1971
37.8 C (100.0 F)
1972
37.2 C (99.0 F)
1973
35.0 C (95.0 F)
1974
36.1 C (97.0 F)
1975
39.4 C (102.9 F)
1976
37.2 C (99.0 F)
1977
36.7 C (98.1 F)
1978
37.2 C (99.0 F)
1979
36.7 C (98.1 F)
1980
37.8 C (100.0 F)
1981
36.1 C (97.0 F)
1982
36.1 C (97.0 F)
1983
38.9 C (102.0 F)
1984
37.8 C (100.0 F)
1985
37.2 C (99.0 F)
1986
34.4 C (93.9 F)
1987
35.6 C (96.1 F)
1988
39.4 C (102.9 F)
1989
37.2 C (99.0 F)
1990
37.2 C (99.0 F)
1991
36.1 C (97.0 F)
1992
34.4 C (93.9 F)
1993
31.7 C (89.1 F)
1994
35.0 C (95.0 F)
1995
38.9 C (102.0 F)
1996
35.6 C (96.1 F)
1997
34.4 C (93.9 F)
1998
37.2 C (99.0 F)
1999
37.2 C (99.0 F)
2000
37.2 C (99.0 F)
2001
37.8 C (100.0 F)
2002
39.4 C (102.9 F)
2003
38.3 C (100.9 F)
2004
38.3 C (100.9 F)
2005
36.7 C (98.1 F)
2006
37.2 C (99.0 F)
2007
40.0 C (104.0 F)
2008
36.1 C (97.0 F)
2009
35.6 C (96.1 F)
2010
35.6 C (96.1 F)
2011
33.9 C (93.0 F)
2012
36.1 C (97.0 F)
2013
33.9 C (93.0 F)
2014
6.1 C (43.0 F)
2015
16.1 C (61.0 F)
2016
n/a
2018
38.3 C (100.9 F)
Coldest night (TNn)
The coldest night of the year at Terry 21 NNW, 1949 to 2018. The record is -38.3 C (-36.9 F) in 1989, marked on the chart; the median year is -33.3 C (-27.9 F).
Coldest night (TNn) at Terry 21 NNW by year
Year
Coldest night (TNn)
1949
n/a
1950
n/a
1951
n/a
1962
-22.8 C (-9.0 F)
1963
-33.9 C (-29.0 F)
1964
-35.0 C (-31.0 F)
1965
-30.6 C (-23.1 F)
1966
-32.2 C (-26.0 F)
1967
-36.7 C (-34.1 F)
1968
-35.6 C (-32.1 F)
1969
-34.4 C (-29.9 F)
1970
-37.2 C (-35.0 F)
1971
-34.4 C (-29.9 F)
1972
-35.6 C (-32.1 F)
1973
-31.7 C (-25.1 F)
1974
-36.7 C (-34.1 F)
1975
-31.7 C (-25.1 F)
1976
-33.9 C (-29.0 F)
1977
-37.2 C (-35.0 F)
1978
-32.8 C (-27.0 F)
1979
-32.8 C (-27.0 F)
1980
-34.4 C (-29.9 F)
1981
-31.1 C (-24.0 F)
1982
-37.8 C (-36.0 F)
1983
-37.2 C (-35.0 F)
1984
-33.3 C (-27.9 F)
1985
-34.4 C (-29.9 F)
1986
-35.0 C (-31.0 F)
1987
-23.9 C (-11.0 F)
1988
-33.3 C (-27.9 F)
1989
-38.3 C (-36.9 F)
1990
-35.6 C (-32.1 F)
1991
-31.1 C (-24.0 F)
1992
-34.4 C (-29.9 F)
1993
-32.8 C (-27.0 F)
1994
-36.1 C (-33.0 F)
1995
-30.6 C (-23.1 F)
1996
-36.7 C (-34.1 F)
1997
-32.8 C (-27.0 F)
1998
-33.9 C (-29.0 F)
1999
-31.7 C (-25.1 F)
2000
-30.6 C (-23.1 F)
2001
-27.2 C (-17.0 F)
2002
-32.8 C (-27.0 F)
2003
-34.4 C (-29.9 F)
2004
-31.7 C (-25.1 F)
2005
-35.0 C (-31.0 F)
2006
-32.8 C (-27.0 F)
2007
-30.6 C (-23.1 F)
2008
-33.3 C (-27.9 F)
2009
-37.2 C (-35.0 F)
2010
-32.2 C (-26.0 F)
2011
-35.0 C (-31.0 F)
2012
-28.3 C (-18.9 F)
2013
-23.9 C (-11.0 F)
2014
-30.6 C (-23.1 F)
2015
-31.1 C (-24.0 F)
2016
n/a
2018
0.6 C (33.1 F)
Wettest day (Rx1day)
The wettest day of the year at Terry 21 NNW, 1949 to 2018. The record is 118.9 mm (4.7 in) in 1997, marked on the chart; the median year is 33.2 mm (1.3 in).
Wettest day (Rx1day) at Terry 21 NNW by year
Year
Wettest day (Rx1day)
1949
2.0 mm (0.08 in)
1950
17.8 mm (0.7 in)
1951
28.7 mm (1.1 in)
1962
68.6 mm (2.7 in)
1963
55.9 mm (2.2 in)
1964
70.4 mm (2.8 in)
1965
66.0 mm (2.6 in)
1966
31.0 mm (1.2 in)
1967
45.0 mm (1.8 in)
1968
55.9 mm (2.2 in)
1969
48.8 mm (1.9 in)
1970
25.4 mm (1.0 in)
1971
31.5 mm (1.2 in)
1972
33.3 mm (1.3 in)
1973
93.2 mm (3.7 in)
1974
30.2 mm (1.2 in)
1975
50.3 mm (2.0 in)
1976
37.6 mm (1.5 in)
1977
21.3 mm (0.8 in)
1978
53.8 mm (2.1 in)
1979
22.1 mm (0.9 in)
1980
37.1 mm (1.5 in)
1981
42.4 mm (1.7 in)
1982
40.6 mm (1.6 in)
1983
15.7 mm (0.6 in)
1984
18.5 mm (0.7 in)
1985
42.7 mm (1.7 in)
1986
76.7 mm (3.0 in)
1987
26.2 mm (1.0 in)
1988
30.5 mm (1.2 in)
1989
72.6 mm (2.9 in)
1990
28.4 mm (1.1 in)
1991
45.0 mm (1.8 in)
1992
98.0 mm (3.9 in)
1993
43.7 mm (1.7 in)
1994
24.4 mm (1.0 in)
1995
22.4 mm (0.9 in)
1996
27.9 mm (1.1 in)
1997
118.9 mm (4.7 in)
1998
39.9 mm (1.6 in)
1999
27.7 mm (1.1 in)
2000
18.3 mm (0.7 in)
2001
37.8 mm (1.5 in)
2002
24.6 mm (1.0 in)
2003
27.9 mm (1.1 in)
2004
14.5 mm (0.6 in)
2005
43.4 mm (1.7 in)
2006
30.0 mm (1.2 in)
2007
23.4 mm (0.9 in)
2008
49.5 mm (1.9 in)
2009
32.5 mm (1.3 in)
2010
50.8 mm (2.0 in)
2011
65.0 mm (2.6 in)
2012
33.0 mm (1.3 in)
2013
61.0 mm (2.4 in)
2014
n/a
2015
21.8 mm (0.9 in)
2016
22.6 mm (0.9 in)
2018
28.4 mm (1.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Terry 21 NNW, 1949 to 2018. The record is 130.2 mm (5.1 in) in 1992, marked on the chart; the median year is 52.8 mm (2.1 in).
Wettest five days (Rx5day) at Terry 21 NNW by year
Year
Wettest five days (Rx5day)
1949
3.6 mm (0.14 in)
1950
23.9 mm (0.9 in)
1951
61.2 mm (2.4 in)
1962
87.1 mm (3.4 in)
1963
115.6 mm (4.6 in)
1964
77.8 mm (3.1 in)
1965
112.0 mm (4.4 in)
1966
44.2 mm (1.7 in)
1967
107.1 mm (4.2 in)
1968
59.7 mm (2.4 in)
1969
71.7 mm (2.8 in)
1970
49.2 mm (1.9 in)
1971
37.1 mm (1.5 in)
1972
50.4 mm (2.0 in)
1973
117.0 mm (4.6 in)
1974
62.8 mm (2.5 in)
1975
56.2 mm (2.2 in)
1976
49.8 mm (2.0 in)
1977
38.1 mm (1.5 in)
1978
83.5 mm (3.3 in)
1979
22.1 mm (0.9 in)
1980
43.5 mm (1.7 in)
1981
55.9 mm (2.2 in)
1982
47.9 mm (1.9 in)
1983
32.0 mm (1.3 in)
1984
34.7 mm (1.4 in)
1985
75.2 mm (3.0 in)
1986
77.5 mm (3.1 in)
1987
58.4 mm (2.3 in)
1988
32.3 mm (1.3 in)
1989
83.6 mm (3.3 in)
1990
37.9 mm (1.5 in)
1991
67.4 mm (2.7 in)
1992
130.2 mm (5.1 in)
1993
94.1 mm (3.7 in)
1994
34.0 mm (1.3 in)
1995
39.7 mm (1.6 in)
1996
53.7 mm (2.1 in)
1997
121.9 mm (4.8 in)
1998
55.6 mm (2.2 in)
1999
57.1 mm (2.2 in)
2000
27.2 mm (1.1 in)
2001
59.6 mm (2.3 in)
2002
33.8 mm (1.3 in)
2003
37.0 mm (1.5 in)
2004
24.4 mm (1.0 in)
2005
45.2 mm (1.8 in)
2006
36.4 mm (1.4 in)
2007
51.8 mm (2.0 in)
2008
65.0 mm (2.6 in)
2009
45.7 mm (1.8 in)
2010
110.0 mm (4.3 in)
2011
n/a
2012
n/a
2013
102.4 mm (4.0 in)
2014
n/a
2015
28.2 mm (1.1 in)
2016
34.6 mm (1.4 in)
2018
34.0 mm (1.3 in)
Longest dry spell (CDD)
The longest dry spell of the year at Terry 21 NNW, 1949 to 2018. The record is 78 days in 1963, marked on the chart; the median year is 34 days.
Longest dry spell (CDD) at Terry 21 NNW by year
Year
Longest dry spell (CDD)
1949
4 days
1950
20 days
1951
28 days
1962
46 days
1963
78 days
1964
39 days
1965
44 days
1966
31 days
1967
51 days
1968
35 days
1969
40 days
1970
34 days
1971
34 days
1972
34 days
1973
53 days
1974
32 days
1975
25 days
1976
26 days
1977
44 days
1978
19 days
1979
40 days
1980
21 days
1981
41 days
1982
28 days
1983
48 days
1984
28 days
1985
35 days
1986
27 days
1987
54 days
1988
38 days
1989
22 days
1990
34 days
1991
29 days
1992
27 days
1993
37 days
1994
28 days
1995
27 days
1996
27 days
1997
61 days
1998
37 days
1999
55 days
2000
37 days
2001
68 days
2002
32 days
2003
31 days
2004
65 days
2005
57 days
2006
43 days
2007
43 days
2008
30 days
2009
42 days
2010
54 days
2011
1 day
2012
2 days
2013
19 days
2014
n/a
2015
24 days
2016
18 days
2018
22 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
44 years with a frost
Across 44 years with a frost, the median last spring frost at Terry 21 NNW falls on 23 May and the median first autumn frost on 15 September, which leaves a median of 116 days between them.
Fitted over all years, the growing season changes by -3.9 days per decade at this station.
Frost dates and growing season at Terry 21 NNW
Measure
Median, all years
Earliest period
Recent period (1979 to 2009)
Recent against earliest
Fitted trend
Last spring frost
23 May
n/a
26 May
n/a
+2.6 days per decade
First autumn frost
15 September
n/a
16 September
n/a
-1.3 days per decade
Growing days
116 days
n/a
113 days
n/a
-3.9 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, 1963 to 2010
A day with at least 35.9 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 134.6 mm (5.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Terry 21 NNW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
35.9 mm (1.4 in)
5 years
54.6 mm (2.1 in)
10 years
69.5 mm (2.7 in)
25 years
92.1 mm (3.6 in)
50 years
111.9 mm (4.4 in)
Longer than the 44 years of record
100 years
134.6 mm (5.3 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 1963 to 2010.
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: 118.9 mm (4.7 in) in 1997; 98.0 mm (3.9 in) in 1992; 93.2 mm (3.7 in) in 1973.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Terry 21 NNW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Terry 21 NNW 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.