Record envelope, standing records and threshold days for Alder 17 S (USC00240110), Montana, United States, with 53 years of record.
Key Facts for Alder 17 S
Alder 17 S (USC00240110) is a weather station in Montana, United States at 45.07 latitude and -112.06 longitude, 1,783 m (5,850 ft) above sea level.
The station reports from 1956 to 2008, 53 years of record.
1,464 records set at Alder 17 S still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Alder 17 S tied a daily record snow depth of 7.6 cm (3.0 in) on 18 January 2008.
About the Station
Location: Montana, United States, 45.07 latitude, -112.06 longitude.
Elevation: 1,783 m (5,850 ft).
Period of record: 1956 to 2008, 53 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 Alder 17 S. 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 Alder 17 S, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
14.4 C (57.9 F)
-37.2 C (-35.0 F)
n/a
n/a
Feb
16.7 C (62.1 F)
-34.4 C (-29.9 F)
n/a
n/a
Mar
21.1 C (70.0 F)
-28.3 C (-18.9 F)
n/a
n/a
Apr
26.7 C (80.1 F)
-18.9 C (-2.0 F)
n/a
n/a
May
31.7 C (89.1 F)
-11.7 C (10.9 F)
n/a
n/a
Jun
35.0 C (95.0 F)
-5.6 C (21.9 F)
n/a
n/a
Jul
35.6 C (96.1 F)
-4.4 C (24.1 F)
n/a
n/a
Aug
36.1 C (97.0 F)
-5.0 C (23.0 F)
n/a
n/a
Sep
32.8 C (91.0 F)
-13.3 C (8.1 F)
n/a
n/a
Oct
28.3 C (82.9 F)
-22.8 C (-9.0 F)
n/a
n/a
Nov
22.2 C (72.0 F)
-33.9 C (-29.0 F)
n/a
n/a
Dec
15.0 C (59.0 F)
-40.6 C (-41.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Alder 17 S still stand. 1987 holds the most, with 45.
Standing records at Alder 17 S by the year they were set
Year set
Standing records
1956
6
1957
25
1958
31
1959
30
1960
31
1961
29
1962
40
1963
38
1964
24
1965
35
1966
37
1967
23
1968
23
1969
36
1970
17
1971
19
1972
26
1973
15
1974
33
1975
32
1976
28
1977
22
1978
29
1979
20
1980
36
1981
22
1982
22
1983
32
1984
29
1985
32
1986
40
1987
45
1988
32
1989
36
1990
29
1991
21
1992
26
1993
32
1994
21
1995
32
1996
44
1997
25
1998
22
1999
32
2000
19
2001
29
2002
26
2003
38
2004
11
2005
24
2006
25
2007
33
All-Time Record Progression
3 new records
3 all-time records were set at Alder 17 S between 11 March 1991 and 31 July 2000. Each dot is a new record.
When Alder 17 S set new all-time records
Date
Kind
Detail
1991-03-11
Record daily snowfall
Record daily snowfall 31.8 cm (12.5 in)
1998-01-19
Record snow depth
Record snow depth 33.0 cm (13.0 in)
2000-07-31
Record high minimum temperature
Record high minimum temperature 20.6 C (69.1 F)
Wettest Day of Each Month
May: 53.1 mm (2.1 in)
The wettest day on record for each calendar month at Alder 17 S. The most was 53.1 mm (2.1 in) on 31 May 1985.
Record daily precipitation for each month at Alder 17 S
Month
Record daily precipitation (mm)
Date
Jan
12.4 mm (0.5 in)
23 January 1989
Feb
26.4 mm (1.0 in)
14 February 1995
Mar
24.9 mm (1.0 in)
29 March 1967
Apr
46.2 mm (1.8 in)
25 April 1975
May
53.1 mm (2.1 in)
31 May 1985
Jun
38.9 mm (1.5 in)
10 June 2004
Jul
43.2 mm (1.7 in)
22 July 1975
Aug
33.8 mm (1.3 in)
12 August 1969
Sep
37.1 mm (1.5 in)
15 September 1966
Oct
30.0 mm (1.2 in)
28 October 2004
Nov
17.5 mm (0.7 in)
7 November 1969
Dec
16.5 mm (0.6 in)
22 December 1973
Period of Record Coverage
1956 to 2008
Complete yearUnder 90 percent of days
53 years of record at Alder 17 S, 1956 to 2008. 2 years have data for under 90 percent of days and are left out of rankings: 1956, 2008.
Cooler than the station meanWarmer than the station mean
One stripe for each of 51 complete years at Alder 17 S, 1957 to 2007. Blue stripes are years cooler than the station's own mean of 5.4 C (41.7 F); red stripes are warmer. The coolest year was 1985, at 3.5 C (38.2 F), and the warmest was 1987, at 6.7 C (44.0 F). The strongest colour marks a difference of 2.0 C (3.6 F).
Annual mean temperature at Alder 17 S as warming stripes, 1957 to 2007
Year
Annual mean temperature
Difference from the station mean
1957
5.2 C
-0.19 C
1958
6.1 C
+0.73 C
1959
4.9 C
-0.51 C
1960
4.9 C
-0.53 C
1961
5.7 C
+0.32 C
1962
5.4 C
+0.01 C
1963
6.1 C
+0.72 C
1964
4.8 C
-0.65 C
1965
5.2 C
-0.19 C
1966
5.6 C
+0.23 C
1967
5.4 C
-0.01 C
1968
4.7 C
-0.74 C
1969
5.4 C
+0.03 C
1970
5.3 C
-0.12 C
1971
4.9 C
-0.51 C
1972
4.9 C
-0.55 C
1973
5.1 C
-0.31 C
1974
5.6 C
+0.16 C
1975
3.6 C
-1.81 C
1976
5.6 C
+0.16 C
1977
5.3 C
-0.11 C
1978
4.5 C
-0.92 C
1979
3.9 C
-1.49 C
1980
5.4 C
-0.02 C
1981
6.2 C
+0.74 C
1982
4.1 C
-1.31 C
1983
4.7 C
-0.75 C
1984
4.7 C
-0.74 C
1985
3.5 C
-1.94 C
1986
6.5 C
+1.09 C
1987
6.7 C
+1.24 C
1988
6.6 C
+1.15 C
1989
5.3 C
-0.10 C
1990
5.8 C
+0.36 C
1991
5.9 C
+0.49 C
1992
6.3 C
+0.84 C
1993
4.1 C
-1.27 C
1994
6.1 C
+0.64 C
1995
5.6 C
+0.16 C
1996
5.2 C
-0.22 C
1997
5.4 C
-0.02 C
1998
6.0 C
+0.59 C
1999
6.1 C
+0.73 C
2000
5.7 C
+0.27 C
2001
6.2 C
+0.74 C
2002
5.0 C
-0.40 C
2003
6.2 C
+0.82 C
2004
6.0 C
+0.57 C
2005
6.2 C
+0.78 C
2006
6.2 C
+0.80 C
2007
6.2 C
+0.80 C
The annual mean temperature here has risen by 0.16 C (0.03 to 0.30) per decade over 1957 to 2007. In Fahrenheit: 0.30 F (0.05 to 0.55) per decade. The slope is a straight line fitted to 51 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Alder 17 S
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.16 C (0.03 to 0.30) per decade
0.30 F (0.05 to 0.55) per decade
1957 to 2007
51
Rise
Mean daily maximum
-0.1 C (-0.2 to 0.1) per decade
-0.1 F (-0.4 to 0.2) per decade
1957 to 2007
51
Not clearly different from zero
Mean daily minimum
0.4 C (0.2 to 0.5) per decade
0.7 F (0.4 to 1.0) per decade
1957 to 2007
51
Rise
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
1956 to 2008
Yearly extremes at Alder 17 S: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.1 C (97.0 F)
1961
32.8 C (91.0 F)
53
Coldest night (TNn)
-40.6 C (-41.1 F)
1983
-30.6 C (-23.1 F)
53
Wettest day (Rx1day)
53.1 mm (2.1 in)
1985
25.7 mm (1.0 in)
53
Wettest five days (Rx5day)
65.8 mm (2.6 in)
1964
39.6 mm (1.6 in)
53
Longest dry spell (CDD)
54 days
1999
30 days
53
Hottest day (TXx)
The hottest day of the year at Alder 17 S, 1956 to 2008. The record is 36.1 C (97.0 F) in 1961, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Alder 17 S by year
Year
Hottest day (TXx)
1956
25.6 C (78.1 F)
1957
32.8 C (91.0 F)
1958
33.3 C (91.9 F)
1959
34.4 C (93.9 F)
1960
35.0 C (95.0 F)
1961
36.1 C (97.0 F)
1962
31.1 C (88.0 F)
1963
33.3 C (91.9 F)
1964
32.2 C (90.0 F)
1965
32.8 C (91.0 F)
1966
35.0 C (95.0 F)
1967
32.8 C (91.0 F)
1968
32.8 C (91.0 F)
1969
35.0 C (95.0 F)
1970
32.2 C (90.0 F)
1971
32.8 C (91.0 F)
1972
32.2 C (90.0 F)
1973
32.8 C (91.0 F)
1974
33.9 C (93.0 F)
1975
32.8 C (91.0 F)
1976
32.2 C (90.0 F)
1977
32.8 C (91.0 F)
1978
32.2 C (90.0 F)
1979
32.8 C (91.0 F)
1980
32.2 C (90.0 F)
1981
32.2 C (90.0 F)
1982
31.1 C (88.0 F)
1983
34.4 C (93.9 F)
1984
31.1 C (88.0 F)
1985
30.6 C (87.1 F)
1986
31.7 C (89.1 F)
1987
30.6 C (87.1 F)
1988
35.0 C (95.0 F)
1989
33.9 C (93.0 F)
1990
32.2 C (90.0 F)
1991
32.8 C (91.0 F)
1992
31.7 C (89.1 F)
1993
28.9 C (84.0 F)
1994
31.7 C (89.1 F)
1995
31.7 C (89.1 F)
1996
33.9 C (93.0 F)
1997
31.1 C (88.0 F)
1998
35.0 C (95.0 F)
1999
33.3 C (91.9 F)
2000
33.9 C (93.0 F)
2001
35.6 C (96.1 F)
2002
35.6 C (96.1 F)
2003
35.6 C (96.1 F)
2004
33.9 C (93.0 F)
2005
34.4 C (93.9 F)
2006
33.9 C (93.0 F)
2007
35.6 C (96.1 F)
2008
5.0 C (41.0 F)
Coldest night (TNn)
The coldest night of the year at Alder 17 S, 1956 to 2008. The record is -40.6 C (-41.1 F) in 1983, marked on the chart; the median year is -30.6 C (-23.1 F).
Coldest night (TNn) at Alder 17 S by year
Year
Coldest night (TNn)
1956
-29.4 C (-20.9 F)
1957
-35.0 C (-31.0 F)
1958
-23.3 C (-9.9 F)
1959
-33.9 C (-29.0 F)
1960
-30.6 C (-23.1 F)
1961
-32.2 C (-26.0 F)
1962
-36.1 C (-33.0 F)
1963
-37.2 C (-35.0 F)
1964
-34.4 C (-29.9 F)
1965
-26.7 C (-16.1 F)
1966
-25.0 C (-13.0 F)
1967
-28.9 C (-20.0 F)
1968
-30.0 C (-22.0 F)
1969
-31.7 C (-25.1 F)
1970
-27.8 C (-18.0 F)
1971
-33.3 C (-27.9 F)
1972
-35.0 C (-31.0 F)
1973
-34.4 C (-29.9 F)
1974
-30.6 C (-23.1 F)
1975
-32.2 C (-26.0 F)
1976
-27.2 C (-17.0 F)
1977
-30.0 C (-22.0 F)
1978
-38.9 C (-38.0 F)
1979
-35.0 C (-31.0 F)
1980
-35.0 C (-31.0 F)
1981
-32.8 C (-27.0 F)
1982
-34.4 C (-29.9 F)
1983
-40.6 C (-41.1 F)
1984
-29.4 C (-20.9 F)
1985
-30.6 C (-23.1 F)
1986
-25.6 C (-14.1 F)
1987
-27.2 C (-17.0 F)
1988
-25.6 C (-14.1 F)
1989
-33.3 C (-27.9 F)
1990
-34.4 C (-29.9 F)
1991
-27.2 C (-17.0 F)
1992
-25.0 C (-13.0 F)
1993
-28.9 C (-20.0 F)
1994
-24.4 C (-11.9 F)
1995
-23.9 C (-11.0 F)
1996
-32.8 C (-27.0 F)
1997
-32.2 C (-26.0 F)
1998
-32.2 C (-26.0 F)
1999
-20.0 C (-4.0 F)
2000
-25.0 C (-13.0 F)
2001
-24.4 C (-11.9 F)
2002
-27.2 C (-17.0 F)
2003
-31.1 C (-24.0 F)
2004
-33.3 C (-27.9 F)
2005
-29.4 C (-20.9 F)
2006
-28.9 C (-20.0 F)
2007
-33.3 C (-27.9 F)
2008
-29.4 C (-20.9 F)
Wettest day (Rx1day)
The wettest day of the year at Alder 17 S, 1956 to 2008. The record is 53.1 mm (2.1 in) in 1985, marked on the chart; the median year is 25.7 mm (1.0 in).
Wettest day (Rx1day) at Alder 17 S by year
Year
Wettest day (Rx1day)
1956
7.6 mm (0.30 in)
1957
22.9 mm (0.9 in)
1958
18.0 mm (0.7 in)
1959
30.7 mm (1.2 in)
1960
16.8 mm (0.7 in)
1961
23.4 mm (0.9 in)
1962
21.3 mm (0.8 in)
1963
23.6 mm (0.9 in)
1964
28.7 mm (1.1 in)
1965
20.8 mm (0.8 in)
1966
37.1 mm (1.5 in)
1967
38.9 mm (1.5 in)
1968
25.4 mm (1.0 in)
1969
33.8 mm (1.3 in)
1970
25.7 mm (1.0 in)
1971
22.1 mm (0.9 in)
1972
27.9 mm (1.1 in)
1973
30.0 mm (1.2 in)
1974
25.4 mm (1.0 in)
1975
46.2 mm (1.8 in)
1976
23.6 mm (0.9 in)
1977
30.5 mm (1.2 in)
1978
27.4 mm (1.1 in)
1979
24.1 mm (0.9 in)
1980
42.7 mm (1.7 in)
1981
36.3 mm (1.4 in)
1982
21.3 mm (0.8 in)
1983
22.1 mm (0.9 in)
1984
22.6 mm (0.9 in)
1985
53.1 mm (2.1 in)
1986
35.6 mm (1.4 in)
1987
37.8 mm (1.5 in)
1988
31.8 mm (1.3 in)
1989
15.0 mm (0.6 in)
1990
22.9 mm (0.9 in)
1991
19.1 mm (0.8 in)
1992
25.7 mm (1.0 in)
1993
40.6 mm (1.6 in)
1994
14.7 mm (0.6 in)
1995
28.2 mm (1.1 in)
1996
20.8 mm (0.8 in)
1997
24.1 mm (0.9 in)
1998
26.9 mm (1.1 in)
1999
19.8 mm (0.8 in)
2000
25.4 mm (1.0 in)
2001
27.2 mm (1.1 in)
2002
21.6 mm (0.9 in)
2003
27.7 mm (1.1 in)
2004
38.9 mm (1.5 in)
2005
29.5 mm (1.2 in)
2006
29.7 mm (1.2 in)
2007
37.6 mm (1.5 in)
2008
3.0 mm (0.12 in)
Wettest five days (Rx5day)
The wettest five days of the year at Alder 17 S, 1956 to 2008. The record is 65.8 mm (2.6 in) in 1964, marked on the chart; the median year is 39.6 mm (1.6 in).
Wettest five days (Rx5day) at Alder 17 S by year
Year
Wettest five days (Rx5day)
1956
11.5 mm (0.5 in)
1957
30.8 mm (1.2 in)
1958
23.6 mm (0.9 in)
1959
61.7 mm (2.4 in)
1960
25.2 mm (1.0 in)
1961
37.6 mm (1.5 in)
1962
32.2 mm (1.3 in)
1963
34.2 mm (1.3 in)
1964
65.8 mm (2.6 in)
1965
32.4 mm (1.3 in)
1966
39.6 mm (1.6 in)
1967
44.0 mm (1.7 in)
1968
39.6 mm (1.6 in)
1969
64.7 mm (2.5 in)
1970
37.9 mm (1.5 in)
1971
41.7 mm (1.6 in)
1972
37.1 mm (1.5 in)
1973
42.4 mm (1.7 in)
1974
26.7 mm (1.1 in)
1975
55.9 mm (2.2 in)
1976
39.1 mm (1.5 in)
1977
40.4 mm (1.6 in)
1978
39.6 mm (1.6 in)
1979
33.8 mm (1.3 in)
1980
65.8 mm (2.6 in)
1981
44.6 mm (1.8 in)
1982
53.8 mm (2.1 in)
1983
38.1 mm (1.5 in)
1984
26.1 mm (1.0 in)
1985
65.6 mm (2.6 in)
1986
46.8 mm (1.8 in)
1987
58.6 mm (2.3 in)
1988
34.6 mm (1.4 in)
1989
32.9 mm (1.3 in)
1990
35.6 mm (1.4 in)
1991
33.5 mm (1.3 in)
1992
35.4 mm (1.4 in)
1993
57.9 mm (2.3 in)
1994
24.4 mm (1.0 in)
1995
63.8 mm (2.5 in)
1996
38.2 mm (1.5 in)
1997
36.5 mm (1.4 in)
1998
44.7 mm (1.8 in)
1999
35.6 mm (1.4 in)
2000
52.9 mm (2.1 in)
2001
53.8 mm (2.1 in)
2002
39.9 mm (1.6 in)
2003
31.5 mm (1.2 in)
2004
56.2 mm (2.2 in)
2005
62.6 mm (2.5 in)
2006
44.2 mm (1.7 in)
2007
50.6 mm (2.0 in)
2008
1.3 mm (0.05 in)
Longest dry spell (CDD)
The longest dry spell of the year at Alder 17 S, 1956 to 2008. The record is 54 days in 1999, marked on the chart; the median year is 30 days.
Longest dry spell (CDD) at Alder 17 S by year
Year
Longest dry spell (CDD)
1956
21 days
1957
27 days
1958
39 days
1959
43 days
1960
21 days
1961
31 days
1962
34 days
1963
45 days
1964
46 days
1965
25 days
1966
27 days
1967
30 days
1968
27 days
1969
31 days
1970
44 days
1971
36 days
1972
40 days
1973
30 days
1974
44 days
1975
49 days
1976
36 days
1977
43 days
1978
28 days
1979
47 days
1980
24 days
1981
35 days
1982
21 days
1983
44 days
1984
24 days
1985
22 days
1986
28 days
1987
45 days
1988
42 days
1989
28 days
1990
45 days
1991
27 days
1992
30 days
1993
33 days
1994
27 days
1995
18 days
1996
22 days
1997
24 days
1998
20 days
1999
54 days
2000
22 days
2001
34 days
2002
29 days
2003
29 days
2004
44 days
2005
29 days
2006
48 days
2007
46 days
2008
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
51 years with a frost
Across 51 years with a frost, the median last spring frost at Alder 17 S falls on 17 June and the median first autumn frost on 31 August, which leaves a median of 78 days between them.
Fitted over all years, the growing season changes by +9.4 days per decade at this station.
Frost dates and growing season at Alder 17 S
Measure
Median, all years
Earliest period
Recent period (1978 to 2007)
Recent against earliest
Fitted trend
Last spring frost
17 June
n/a
15 June
n/a
-2.5 days per decade
First autumn frost
31 August
n/a
6 September
n/a
+7.0 days per decade
Growing days
78 days
n/a
83 days
n/a
+9.4 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
51 years, 1957 to 2007
A day with at least 26.4 mm (1.0 in) of rain is expected about once in 2 years. A day with at least 54.8 mm (2.2 in) of rain is expected about once in 100 years.
Rainfall return levels at Alder 17 S: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
26.4 mm (1.0 in)
5 years
33.7 mm (1.3 in)
10 years
38.7 mm (1.5 in)
25 years
45.1 mm (1.8 in)
50 years
49.9 mm (2.0 in)
100 years
54.8 mm (2.2 in)
Longer than the 51 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, 51 years of values from 1957 to 2007.
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: 53.1 mm (2.1 in) in 1985; 46.2 mm (1.8 in) in 1975; 42.7 mm (1.7 in) in 1980.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Alder 17 S standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Alder 17 S 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.