HELENA, MONTANA
NORMALS, MEANS, AND EXTREMES

LATITUDE: 46 Deg. 36 Min. N LONGITUDE: 112 Deg. 00 Min. W ELEVATION: FT. GRND 3828 BARO 3898 TIME ZONE: MOUNTAIN WBAN: 24144

(a)
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
YEAR
TEMPERATURE (Deg. F)
Normals
-Daily Maximum
-Daily Minimum
-Monthly
Extremes
-Record Highest
-Year
-Record Lowest
-Year






54

54



29.6
9.6
19.6

62
1992
-42
1957


36.9
15.9
26.4

68
1950
-33
1989


44.8
22.3
33.6

77
1978
-30
1955


56.1
30.6
43.4

86
1992
1
1954


65.4
39.6
52.5

92
1986
17
1954


75.8
48.3
62.1

100
1988
30
1969


85.0
53.4
69.2

102
1981
36
1971


83.2
51.7
67.4

105
1969
28
1992


69.8
41.0
55.4

99
1967
18
1970


58.5
31.6
45,1

85
1992
-8
1991


42.4
20.7
31.6

72
1990
-39
1959


31.3
11.2
21.2

64
1980
-38
1964


56.6
31.3
44.0

105
AUG 1969
-42
JAN 1957
NORMAL DEGREE DAYS
Heating (base 65 Deg. F)
Cooling (base 65 Deg. F)




1407
0

1081
0

973
0

648
0

388
0

137
50

34
164

65
139

321
33

617
0

1002
0

1358
0

8031
386
% OF POSSIBLE SUNSHINE
54
46
55
61
59
61
63
78
74
68
60
44
42
59
MEAN SKY COVER(tenths)
Sunrise - Sunset
MEAN NUMBER OF DAYS:
Sunrise to Sunset
-Clear
-Partly Cloudy
-Cloudy
Precipitation
.01 inches or more
Snow, Ice Pellets, Hail
1.0 inches or more
Thunderstorms
Heavy Fog Visibility
1/4 mile or less
Temperature Deg. F
-Maximum
90 Deg. F and above
32 Deg. F and below
-Minimum
32 Deg. F and below
0 Deg. F and below

54


54
54
54

54

54
54

54


31
31

31
31

7.5


4.6
6.1
20.2

7.9

2.7
0.1

1.6


0.0
14.5

29.4
8.5

7.3


4.4
6,6
17.3

6.5

1.9
0.1

1.1


0.0
8.3

26.5
4.5

7.3


3.9
8.3
18.8

8.4

2.4
0.1

0.8


0.0
3.8

27.2
1.5

7.3


3.8
8.6
17.6

8.3

1.4
1.0

0.3


0.0
0.5

17.6
0.0

6.8


5.0
9.8
16.2

11.1

0.4
4.3

0.2


0.2
0.0

3.5
0.0

6.3


5.8
11.2
13.0

11.2

0.*
7.6

0.1


2.3
0.0

0.1
0.0

4.1


14.4
10.6
5.9

7.6

0.0
8.8

0.1


7.6
0.0

0.0
0.0

4.6


12.9
11.0
7.1

7.6

0.*
8.0

0.1


7.2
0.0

0.*
0.0

5.3


10.5
8.7
10.8

6.5

0.4
1.8

0.3


1.1
0.0

3.4
0.0

6.1


8.2
8.7
14.1

5.7

0.7
0.3

0.5


0.0
0.6

16.9
0.2

7.2


4.6
7.5
17.9

7.0

1.7
0.1

1.2


0.0
5.4

27.0
1.8

7.5


4.0
7.3
19.7

7.8

2.4
0.*

2.0


0.0
14.6

29.7
6.1

6.4


82.1
104.4
178.6

95.5

14.1
32.2

8.2


18.5
47.6

181.4
22.6
AV. STATION PRES. (mb)
22
881.5
880.9
878.5
879.5
879.3
880.2
882.0
882.1
882.7
882.5
881.0
881.5
881.0
RELATIVE HUMIDITY (%)
Hour 04
Hour 10 (Local Time)
Hour 16
Hour 22

29
31
31
31

72
67
63
70

72
63
54
69

73
55
46
66

71
47
39
60

71
44
38
59

72
44
37
59

67
39
30
52

67
41
31
52

72
47
35
59

73
53
42
64

74
62
58
70

73
68
66
72

71
53
45
63
PRECIPITATION (in.)
Water Equivalent
-Normal
-Maximum Monthly
-Year
-Minimum Monthly
-Year
-Maximum in 24 hrs
-Year
Snow, Ice Pellets, Hail
-Maximum Monthly
-Year
-Maximum in 24 hrs
-Year



54

54

54


54

54



0.63
2.78
1969
T
1987
0.77
1969

35.6
1969
11.5
1969


0.41
1.20
1986
0.02
1991
0.58
1953

19.7
1959
11.7
1993


0.73
1.62
1982
0.02
1959
1.01
1957

21.6
1955
8.7
1955


0.97
3.00
1975
0.10
1977
1.25
1951

20.6
1967
12.9
1960


1.78
6.09
1981
0.29
1979
2.31
1981

12.7
1967
12.5
1967


1.87
4.74
1944
0.08
1985
1.78
1979

2.7
1969
2.7
1969


1.10
4.70
1993
0.08
1973
2.26
1983

T
1993
T
1993


1.29
4.23
1974
0.02
1988
1.86
1974

6.2
1992
6.2
1992


1.15
3.37
1965
0.08
1972
1.61
1980

13.7
1965
13.3
1957


0.60
2.68
1975
0.02
1978
0.85
1954

11.0
1969
7.4
1969


0.48
1.50
1950
0.04
1969
0.82
1959

32.9
1959
21.5
1959


0.59
1.48
1977
0.04
1976
0.51
1982

22.8
1967
10.7
1991


11.60
6.09
MAY 1981
T
JAN 1987
2.31
MAY 1981

35.6
JAN 1969
21.5
NOV 1959
WIND
Mean Speed (mph)
Prevailing Direction
through 1964
Fastest Mile
-Direction(!!)
-Speed(mph)
-Year
Peak Gust
-Direction(!!)
-Speed(mph)
-Date

54



54
54


11
11


6.7

W

SW
73
1944

W
64
1990

7.3

W

W
73
1949

W
63
1988

8.3

W

SW
61
1955

W
52
1987

9.1

W

W
52
1950

W
55
1989

8.8

W

SW
56
1975

W
58
1989

8.5

W

W
56
1970

SW
64
1994

7.8

W

SW
65
1975

W
64
1990

7.4

W

S
65
1947

S
58
1992

7.4

W

NW
54
1943

W
51
1984

7.1

W

W
62
1948

W
60
1991

7.1

W

SW
56
1962

SW
61
1990

6.7

W

NW
59
1946

W
58
1992

7.7

W

W
73
FEB 1949

SW
64
JUN 1994
(a) - Length of Record in Years, although individual months may be missing.
0.* or * - The value is between 0.0 and 0.05.
Normals - Based on the 1961 - 1990 record period.
Extremes - Dates are the most recent occurrence.
Wind Dir.- Numerals show tens of degrees clockwise from true north. "00" indicates calm.
Resultant Directions are given to whole degrees.