Record envelope, standing records and threshold days for Blackleaf (USC00240877), Montana, United States, with 106 years of record.
Key Facts for Blackleaf
Blackleaf (USC00240877) is a weather station in Montana, United States at 48.01 latitude and -112.44 longitude, 1,291 m (4,235 ft) above sea level.
The station reports from 1905 to 2010, 106 years of record.
1,464 records set at Blackleaf still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Blackleaf set a daily record high maximum temperature of 28.9 C (84.0 F) on 2 October 2010.
About the Station
Location: Montana, United States, 48.01 latitude, -112.44 longitude.
Elevation: 1,291 m (4,235 ft).
Period of record: 1905 to 2010, 106 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 Blackleaf. 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 Blackleaf, 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)
-43.3 C (-45.9 F)
n/a
n/a
Feb
21.1 C (70.0 F)
-43.9 C (-47.0 F)
n/a
n/a
Mar
25.0 C (77.0 F)
-40.0 C (-40.0 F)
n/a
n/a
Apr
28.9 C (84.0 F)
-23.9 C (-11.0 F)
n/a
n/a
May
33.9 C (93.0 F)
-15.0 C (5.0 F)
n/a
n/a
Jun
34.4 C (93.9 F)
-11.1 C (12.0 F)
n/a
n/a
Jul
38.9 C (102.0 F)
-4.4 C (24.1 F)
n/a
n/a
Aug
38.9 C (102.0 F)
-5.0 C (23.0 F)
n/a
n/a
Sep
35.6 C (96.1 F)
-12.2 C (10.0 F)
n/a
n/a
Oct
30.6 C (87.1 F)
-28.9 C (-20.0 F)
n/a
n/a
Nov
27.8 C (82.0 F)
-36.7 C (-34.1 F)
n/a
n/a
Dec
20.0 C (68.0 F)
-41.7 C (-43.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Blackleaf still stand. 1909 holds the most, with 53.
Standing records at Blackleaf by the year they were set
Year set
Standing records
1907
6
1908
33
1909
53
1910
46
1911
31
1912
16
1913
23
1914
22
1915
9
1916
23
1917
50
1918
19
1919
30
1920
13
1921
3
1954
14
1955
21
1956
31
1957
17
1958
13
1959
16
1960
24
1961
14
1962
18
1963
16
1964
15
1965
12
1966
15
1967
38
1968
26
1969
29
1970
15
1971
23
1972
20
1973
26
1974
14
1975
25
1976
13
1977
18
1978
4
1979
12
1980
26
1981
17
1982
15
1983
25
1984
25
1985
40
1986
33
1987
34
1988
19
1989
12
1990
22
1991
19
1992
36
1993
20
1994
18
1995
13
1996
29
1997
12
1998
11
1999
22
2000
14
2001
9
2002
23
2003
27
2004
15
2005
27
2006
7
2007
12
2009
9
2010
7
All-Time Record Progression
2 new records
2 all-time records were set at Blackleaf between 8 June 1964 and 8 February 1994. Each dot is a new record.
When Blackleaf set new all-time records
Date
Kind
Detail
1964-06-08
Record daily precipitation
Record daily precipitation 119.4 mm (4.7 in)
1994-02-08
Record low minimum temperature
Record low minimum temperature -43.9 C (-47.0 F)
Wettest Day of Each Month
Jun: 119.4 mm (4.7 in)
The wettest day on record for each calendar month at Blackleaf. The most was 119.4 mm (4.7 in) on 8 June 1964.
Record daily precipitation for each month at Blackleaf
Month
Record daily precipitation (mm)
Date
Jan
25.4 mm (1.0 in)
23 January 2010
Feb
25.4 mm (1.0 in)
1 February 1963
Mar
22.9 mm (0.9 in)
13 March 1907
Apr
61.2 mm (2.4 in)
26 April 1976
May
101.6 mm (4.0 in)
27 May 2010
Jun
119.4 mm (4.7 in)
8 June 1964
Jul
55.1 mm (2.2 in)
13 July 1970
Aug
56.9 mm (2.2 in)
25 August 1989
Sep
89.2 mm (3.5 in)
4 September 1911
Oct
53.8 mm (2.1 in)
4 October 1913
Nov
18.3 mm (0.7 in)
26 November 1999
Dec
15.2 mm (0.6 in)
18 December 1990
Period of Record Coverage
1907 to 2010
Complete yearUnder 90 percent of days
71 years of record at Blackleaf, 1907 to 2010. 33 years have data for under 90 percent of days and are left out of rankings: 1907, 1909, 1915, 1916, 1917, 1918, 1919, 1920 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 35 complete years at Blackleaf, 1908 to 2003. Blue stripes are years cooler than the station's own mean of 5.2 C (41.3 F); red stripes are warmer. The coolest year was 1911, at 3.2 C (37.8 F), and the warmest was 1987, at 7.5 C (45.4 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at Blackleaf as warming stripes, 1908 to 2003
Year
Annual mean temperature
Difference from the station mean
1908
5.4 C
+0.20 C
1911
3.2 C
-1.93 C
1912
4.0 C
-1.13 C
1913
3.4 C
-1.74 C
1914
4.5 C
-0.63 C
1955
3.4 C
-1.79 C
1956
5.1 C
-0.02 C
1957
4.5 C
-0.66 C
1958
5.9 C
+0.78 C
1959
4.8 C
-0.32 C
1960
5.1 C
-0.05 C
1961
5.5 C
+0.34 C
1962
5.1 C
-0.03 C
1963
5.9 C
+0.71 C
1964
4.7 C
-0.47 C
1967
5.4 C
+0.26 C
1968
4.6 C
-0.59 C
1969
4.2 C
-0.97 C
1970
5.0 C
-0.17 C
1972
3.8 C
-1.34 C
1973
5.8 C
+0.66 C
1974
5.9 C
+0.76 C
1975
3.9 C
-1.26 C
1976
6.7 C
+1.50 C
1983
5.6 C
+0.44 C
1985
4.7 C
-0.50 C
1986
7.0 C
+1.86 C
1987
7.5 C
+2.31 C
1988
7.1 C
+1.91 C
1991
5.9 C
+0.70 C
1992
6.0 C
+0.82 C
1993
4.3 C
-0.91 C
1995
4.6 C
-0.55 C
1998
6.3 C
+1.13 C
2003
5.9 C
+0.77 C
The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1908 to 2003. In Fahrenheit: 0.4 F (0.2 to 0.6) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Blackleaf
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.2 C (0.1 to 0.3) per decade
0.4 F (0.2 to 0.6) per decade
1908 to 2003
35
Rise
Mean daily maximum
0.3 C (0.1 to 0.4) per decade
0.5 F (0.2 to 0.8) per decade
1908 to 2003
35
Rise
Mean daily minimum
0.14 C (0.04 to 0.25) per decade
0.3 F (0.1 to 0.4) per decade
1908 to 2003
35
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
1905 to 2010
Yearly extremes at Blackleaf: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
38.9 C (102.0 F)
1969
33.9 C (93.0 F)
71
Coldest night (TNn)
-43.9 C (-47.0 F)
1994
-35.6 C (-32.1 F)
71
Wettest day (Rx1day)
119.4 mm (4.7 in)
1964
33.2 mm (1.3 in)
78
Wettest five days (Rx5day)
186.8 mm (7.4 in)
1908
57.5 mm (2.3 in)
78
Longest dry spell (CDD)
87 days
1969
34 days
78
Hottest day (TXx)
The hottest day of the year at Blackleaf, 1905 to 2010. The record is 38.9 C (102.0 F) in 1969, marked on the chart; the median year is 33.9 C (93.0 F).
Hottest day (TXx) at Blackleaf by year
Year
Hottest day (TXx)
1905
n/a
1906
n/a
1907
25.6 C (78.1 F)
1908
33.9 C (93.0 F)
1909
34.4 C (93.9 F)
1910
33.9 C (93.0 F)
1911
29.4 C (84.9 F)
1912
30.6 C (87.1 F)
1913
31.1 C (88.0 F)
1914
35.0 C (95.0 F)
1915
31.7 C (89.1 F)
1916
27.8 C (82.0 F)
1917
33.3 C (91.9 F)
1918
32.2 C (90.0 F)
1919
36.1 C (97.0 F)
1920
22.8 C (73.0 F)
1921
21.1 C (70.0 F)
1949
n/a
1950
n/a
1951
n/a
1952
n/a
1953
n/a
1954
33.3 C (91.9 F)
1955
31.7 C (89.1 F)
1956
32.2 C (90.0 F)
1957
31.1 C (88.0 F)
1958
31.7 C (89.1 F)
1959
34.4 C (93.9 F)
1960
35.6 C (96.1 F)
1961
37.8 C (100.0 F)
1962
31.7 C (89.1 F)
1963
32.8 C (91.0 F)
1964
32.2 C (90.0 F)
1965
32.2 C (90.0 F)
1966
34.4 C (93.9 F)
1967
35.6 C (96.1 F)
1968
33.3 C (91.9 F)
1969
38.9 C (102.0 F)
1970
33.9 C (93.0 F)
1971
33.9 C (93.0 F)
1972
31.7 C (89.1 F)
1973
37.2 C (99.0 F)
1974
34.4 C (93.9 F)
1975
33.9 C (93.0 F)
1976
33.3 C (91.9 F)
1977
32.2 C (90.0 F)
1978
32.8 C (91.0 F)
1979
33.3 C (91.9 F)
1980
32.8 C (91.0 F)
1981
35.6 C (96.1 F)
1982
32.2 C (90.0 F)
1983
38.3 C (100.9 F)
1984
36.7 C (98.1 F)
1985
36.1 C (97.0 F)
1986
32.2 C (90.0 F)
1987
32.8 C (91.0 F)
1988
34.4 C (93.9 F)
1989
33.3 C (91.9 F)
1990
35.6 C (96.1 F)
1991
35.0 C (95.0 F)
1992
33.9 C (93.0 F)
1993
32.2 C (90.0 F)
1994
34.4 C (93.9 F)
1995
31.7 C (89.1 F)
1996
35.0 C (95.0 F)
1997
30.0 C (86.0 F)
1998
34.4 C (93.9 F)
1999
35.0 C (95.0 F)
2000
36.1 C (97.0 F)
2001
36.1 C (97.0 F)
2002
35.0 C (95.0 F)
2003
36.7 C (98.1 F)
2004
34.4 C (93.9 F)
2005
34.4 C (93.9 F)
2006
33.9 C (93.0 F)
2007
38.9 C (102.0 F)
2009
23.3 C (73.9 F)
2010
29.4 C (84.9 F)
Coldest night (TNn)
The coldest night of the year at Blackleaf, 1905 to 2010. The record is -43.9 C (-47.0 F) in 1994, marked on the chart; the median year is -35.6 C (-32.1 F).
Coldest night (TNn) at Blackleaf by year
Year
Coldest night (TNn)
1905
n/a
1906
n/a
1907
-12.2 C (10.0 F)
1908
-28.9 C (-20.0 F)
1909
-39.4 C (-38.9 F)
1910
-38.9 C (-38.0 F)
1911
-40.6 C (-41.1 F)
1912
-36.1 C (-33.0 F)
1913
-35.6 C (-32.1 F)
1914
-38.3 C (-36.9 F)
1915
-30.6 C (-23.1 F)
1916
-43.3 C (-45.9 F)
1917
-39.4 C (-38.9 F)
1918
-37.2 C (-35.0 F)
1919
-41.7 C (-43.1 F)
1920
-35.6 C (-32.1 F)
1921
-26.1 C (-15.0 F)
1949
n/a
1950
n/a
1951
n/a
1952
n/a
1953
n/a
1954
-25.6 C (-14.1 F)
1955
-36.7 C (-34.1 F)
1956
-37.8 C (-36.0 F)
1957
-37.2 C (-35.0 F)
1958
-25.6 C (-14.1 F)
1959
-37.2 C (-35.0 F)
1960
-33.9 C (-29.0 F)
1961
-33.9 C (-29.0 F)
1962
-31.7 C (-25.1 F)
1963
-35.6 C (-32.1 F)
1964
-37.2 C (-35.0 F)
1965
-31.1 C (-24.0 F)
1966
-25.6 C (-14.1 F)
1967
-30.6 C (-23.1 F)
1968
-40.0 C (-40.0 F)
1969
-37.2 C (-35.0 F)
1970
-31.7 C (-25.1 F)
1971
-40.0 C (-40.0 F)
1972
-41.1 C (-42.0 F)
1973
-28.9 C (-20.0 F)
1974
-33.9 C (-29.0 F)
1975
-31.7 C (-25.1 F)
1976
-31.1 C (-24.0 F)
1977
-35.0 C (-31.0 F)
1978
-33.3 C (-27.9 F)
1979
-36.7 C (-34.1 F)
1980
-33.3 C (-27.9 F)
1981
-37.2 C (-35.0 F)
1982
-34.4 C (-29.9 F)
1983
-40.6 C (-41.1 F)
1984
-31.1 C (-24.0 F)
1985
-35.0 C (-31.0 F)
1986
-36.7 C (-34.1 F)
1987
-26.7 C (-16.1 F)
1988
-35.6 C (-32.1 F)
1989
-37.8 C (-36.0 F)
1990
-37.8 C (-36.0 F)
1991
-33.3 C (-27.9 F)
1992
-35.6 C (-32.1 F)
1993
-32.8 C (-27.0 F)
1994
-43.9 C (-47.0 F)
1995
-37.2 C (-35.0 F)
1996
-38.9 C (-38.0 F)
1997
-35.6 C (-32.1 F)
1998
-37.8 C (-36.0 F)
1999
-27.2 C (-17.0 F)
2000
-32.8 C (-27.0 F)
2001
-30.6 C (-23.1 F)
2002
-40.0 C (-40.0 F)
2003
-32.2 C (-26.0 F)
2004
-37.2 C (-35.0 F)
2005
-37.8 C (-36.0 F)
2006
-37.2 C (-35.0 F)
2007
-27.8 C (-18.0 F)
2009
-38.9 C (-38.0 F)
2010
-29.4 C (-20.9 F)
Wettest day (Rx1day)
The wettest day of the year at Blackleaf, 1905 to 2010. The record is 119.4 mm (4.7 in) in 1964, marked on the chart; the median year is 33.2 mm (1.3 in).
Wettest day (Rx1day) at Blackleaf by year
Year
Wettest day (Rx1day)
1905
18.5 mm (0.7 in)
1906
35.6 mm (1.4 in)
1907
76.2 mm (3.0 in)
1908
94.0 mm (3.7 in)
1909
50.8 mm (2.0 in)
1910
55.9 mm (2.2 in)
1911
89.2 mm (3.5 in)
1912
83.8 mm (3.3 in)
1913
53.8 mm (2.1 in)
1914
19.1 mm (0.8 in)
1915
34.0 mm (1.3 in)
1916
78.7 mm (3.1 in)
1917
31.8 mm (1.3 in)
1918
32.0 mm (1.3 in)
1919
20.3 mm (0.8 in)
1920
34.3 mm (1.4 in)
1921
23.4 mm (0.9 in)
1949
15.2 mm (0.6 in)
1950
33.3 mm (1.3 in)
1951
34.3 mm (1.4 in)
1952
27.9 mm (1.1 in)
1953
84.6 mm (3.3 in)
1954
30.2 mm (1.2 in)
1955
22.4 mm (0.9 in)
1956
47.5 mm (1.9 in)
1957
29.0 mm (1.1 in)
1958
30.2 mm (1.2 in)
1959
21.3 mm (0.8 in)
1960
27.4 mm (1.1 in)
1961
17.8 mm (0.7 in)
1962
24.1 mm (0.9 in)
1963
25.4 mm (1.0 in)
1964
119.4 mm (4.7 in)
1965
27.9 mm (1.1 in)
1966
31.2 mm (1.2 in)
1967
23.6 mm (0.9 in)
1968
38.1 mm (1.5 in)
1969
17.8 mm (0.7 in)
1970
55.1 mm (2.2 in)
1971
21.1 mm (0.8 in)
1972
66.5 mm (2.6 in)
1973
17.0 mm (0.7 in)
1974
29.0 mm (1.1 in)
1975
72.4 mm (2.9 in)
1976
61.2 mm (2.4 in)
1977
19.1 mm (0.8 in)
1978
28.7 mm (1.1 in)
1979
22.1 mm (0.9 in)
1980
38.4 mm (1.5 in)
1981
33.5 mm (1.3 in)
1982
44.5 mm (1.8 in)
1983
44.5 mm (1.8 in)
1984
33.8 mm (1.3 in)
1985
29.7 mm (1.2 in)
1986
34.3 mm (1.4 in)
1987
30.7 mm (1.2 in)
1988
19.1 mm (0.8 in)
1989
56.9 mm (2.2 in)
1990
30.7 mm (1.2 in)
1991
61.2 mm (2.4 in)
1992
27.9 mm (1.1 in)
1993
51.1 mm (2.0 in)
1994
38.1 mm (1.5 in)
1995
47.5 mm (1.9 in)
1996
49.5 mm (1.9 in)
1997
41.4 mm (1.6 in)
1998
29.7 mm (1.2 in)
1999
29.2 mm (1.1 in)
2000
35.6 mm (1.4 in)
2001
27.9 mm (1.1 in)
2002
116.8 mm (4.6 in)
2003
25.4 mm (1.0 in)
2004
33.5 mm (1.3 in)
2005
33.0 mm (1.3 in)
2006
55.9 mm (2.2 in)
2007
12.7 mm (0.5 in)
2009
6.4 mm (0.25 in)
2010
101.6 mm (4.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Blackleaf, 1905 to 2010. The record is 186.8 mm (7.4 in) in 1908, marked on the chart; the median year is 57.5 mm (2.3 in).
Wettest five days (Rx5day) at Blackleaf by year
Year
Wettest five days (Rx5day)
1905
21.1 mm (0.8 in)
1906
66.0 mm (2.6 in)
1907
111.8 mm (4.4 in)
1908
186.8 mm (7.4 in)
1909
118.1 mm (4.6 in)
1910
68.6 mm (2.7 in)
1911
161.7 mm (6.4 in)
1912
125.2 mm (4.9 in)
1913
75.4 mm (3.0 in)
1914
37.3 mm (1.5 in)
1915
66.7 mm (2.6 in)
1916
174.1 mm (6.9 in)
1917
71.3 mm (2.8 in)
1918
35.8 mm (1.4 in)
1919
32.6 mm (1.3 in)
1920
46.5 mm (1.8 in)
1921
12.2 mm (0.5 in)
1949
21.2 mm (0.8 in)
1950
45.8 mm (1.8 in)
1951
48.2 mm (1.9 in)
1952
36.1 mm (1.4 in)
1953
137.0 mm (5.4 in)
1954
41.3 mm (1.6 in)
1955
67.1 mm (2.6 in)
1956
57.0 mm (2.2 in)
1957
48.3 mm (1.9 in)
1958
71.1 mm (2.8 in)
1959
30.5 mm (1.2 in)
1960
45.2 mm (1.8 in)
1961
36.3 mm (1.4 in)
1962
32.3 mm (1.3 in)
1963
31.8 mm (1.3 in)
1964
169.8 mm (6.7 in)
1965
63.4 mm (2.5 in)
1966
78.7 mm (3.1 in)
1967
48.0 mm (1.9 in)
1968
41.9 mm (1.6 in)
1969
70.6 mm (2.8 in)
1970
89.5 mm (3.5 in)
1971
34.1 mm (1.3 in)
1972
114.5 mm (4.5 in)
1973
17.5 mm (0.7 in)
1974
33.0 mm (1.3 in)
1975
105.0 mm (4.1 in)
1976
91.5 mm (3.6 in)
1977
31.1 mm (1.2 in)
1978
48.3 mm (1.9 in)
1979
36.6 mm (1.4 in)
1980
73.9 mm (2.9 in)
1981
65.0 mm (2.6 in)
1982
62.5 mm (2.5 in)
1983
67.1 mm (2.6 in)
1984
33.8 mm (1.3 in)
1985
53.3 mm (2.1 in)
1986
57.9 mm (2.3 in)
1987
58.2 mm (2.3 in)
1988
25.5 mm (1.0 in)
1989
159.3 mm (6.3 in)
1990
35.6 mm (1.4 in)
1991
84.6 mm (3.3 in)
1992
41.9 mm (1.6 in)
1993
104.5 mm (4.1 in)
1994
72.0 mm (2.8 in)
1995
91.5 mm (3.6 in)
1996
64.7 mm (2.5 in)
1997
67.7 mm (2.7 in)
1998
67.3 mm (2.6 in)
1999
38.1 mm (1.5 in)
2000
63.5 mm (2.5 in)
2001
40.6 mm (1.6 in)
2002
116.8 mm (4.6 in)
2003
44.5 mm (1.8 in)
2004
33.5 mm (1.3 in)
2005
28.0 mm (1.1 in)
2006
17.8 mm (0.7 in)
2007
12.7 mm (0.5 in)
2009
10.1 mm (0.4 in)
2010
120.7 mm (4.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Blackleaf, 1905 to 2010. The record is 87 days in 1969, marked on the chart; the median year is 34 days.
Longest dry spell (CDD) at Blackleaf by year
Year
Longest dry spell (CDD)
1905
76 days
1906
44 days
1907
54 days
1908
68 days
1909
41 days
1910
41 days
1911
60 days
1912
35 days
1913
32 days
1914
33 days
1915
37 days
1916
23 days
1917
22 days
1918
55 days
1919
47 days
1920
19 days
1921
15 days
1949
25 days
1950
36 days
1951
21 days
1952
37 days
1953
27 days
1954
51 days
1955
45 days
1956
28 days
1957
36 days
1958
25 days
1959
52 days
1960
42 days
1961
28 days
1962
32 days
1963
44 days
1964
46 days
1965
24 days
1966
24 days
1967
34 days
1968
37 days
1969
87 days
1970
27 days
1971
30 days
1972
34 days
1973
80 days
1974
28 days
1975
24 days
1976
67 days
1977
35 days
1978
18 days
1979
30 days
1980
20 days
1981
34 days
1982
23 days
1983
50 days
1984
54 days
1985
32 days
1986
22 days
1987
44 days
1988
27 days
1989
22 days
1990
40 days
1991
28 days
1992
29 days
1993
29 days
1994
27 days
1995
39 days
1996
31 days
1997
53 days
1998
33 days
1999
35 days
2000
47 days
2001
28 days
2002
59 days
2003
51 days
2004
60 days
2005
35 days
2006
21 days
2007
42 days
2009
24 days
2010
29 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
35 years with a frost
Across 35 years with a frost, the median last spring frost at Blackleaf falls on 7 June and the median first autumn frost on 31 August, which leaves a median of 82 days between them.
Fitted over all years, the growing season changes by +6.4 days per decade at this station.
Frost dates and growing season at Blackleaf
Measure
Median, all years
Earliest period
Recent period (1955 to 2003)
Recent against earliest
Fitted trend
Last spring frost
7 June
n/a
5 June
n/a
-0.8 days per decade
First autumn frost
31 August
n/a
2 September
n/a
+5.6 days per decade
Growing days
82 days
n/a
84 days
n/a
+6.4 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
52 years, 1906 to 2003
A day with at least 34.2 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 154.3 mm (6.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Blackleaf: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
34.2 mm (1.3 in)
5 years
53.4 mm (2.1 in)
10 years
70.2 mm (2.8 in)
25 years
97.4 mm (3.8 in)
50 years
123.0 mm (4.8 in)
100 years
154.3 mm (6.1 in)
Longer than the 52 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, 52 years of values from 1906 to 2003.
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: 119.4 mm (4.7 in) in 1964; 116.8 mm (4.6 in) in 2002; 94.0 mm (3.7 in) in 1908.
Download the Data
Data for Blackleaf standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Blackleaf 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.