LEWISTON, IDAHO
NORMALS, MEANS, AND EXTREMES

LATITUDE: 46 Deg. 23 Min. N LONGITUDE: 117 Deg. 01 Min. W ELEVATION: FT. GRND 1413 BARO 1441 TIME ZONE: PACIFIC WBAN: 24149

(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






49

49



39.6
27.6
33.6

66
1953
-22
1950


46.6
31.5
39.1

72
1986
-15
1950


53.5
34.7
44.1

76
1991
2
1955


61.5
39.7
50.6

97
1977
20
1966


70.2
46.5
58.4

100
1983
23
1954


79.8
53.9
66.9

107
1973
34
1951


89.0
59.2
74.1

110
1967
41
1955


88.3
58.9
73.7

115
1961
41
1992


77.2
50.9
64.1

103
1950
28
1965


63.2
41.4
52.3

89
1987
16
1971


48.1
34.4
41.3

74
1975
-3
1955


40.2
28.7
34.5

63
1965
-22
1968


63.1
42.3
52.7

115
AUG 1961
-22
DEC 1968
NORMAL DEGREE DAYS
Heating (base 65 Deg. F)
Cooling (base 65 Deg. F)




973
0

725
0

648
0

436
0

210
6

64
121

6
288

16
285

141
114

394
0

711
0

946
0

5270
814
% OF POSSIBLE SUNSHINE














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

42


42
42
42

49

49
19

19


49
49

49
49

8.4


2.8
4.2
24.0

11.2

1.8
0.0

3.9


0.0
7.4

21.5
1.3

8.2


2.6
4.7
21.0

9.3

0.8
0.1

3.5


0.0
2.1

16.0
0.2

7.7


4.2
6.2
20.5

10.5

0.4
0.1

1.2


0.0
0.2

11.7
0.0

7.3


4.5
6.5
19.0

9.8

0.*
0.8

0.2


0.1
0.0

3.4
0.0

6.7


6.3
8.7
16.0

9.5

0.0
2.3

0.4


1.3
0.0

0.2
0.0

6.0


8.3
8.6
13.1

8.7

0.0
3.4

0.1


4.7
0.0

0.0
0.0

3.4


18.4
7.1
5.6

4.8

0.0
3.7

0.0


15.8
0.0

0.0
0.0

3.9


16.4
7.6
7.1

4.5

0.0
3.1

0.0


14.1
0.0

0.0
0.0

4.7


13.1
7.4
9.4

5.4

0.0
1.2

0.1


3.6
0.0

0.1
0.0

6.2


8.7
7.3
14.9

7.6

0.*
0.4

2.3


0.0
0.0

3.0
0.0

8.2


2.6
5.6
21.7

10.7

0.6
0.1

4.2


0.0
1.2

11.9
0.1

8.4


2.8
3.9
24.3

10.9

1.6
0.0

5.5


0.0
4.9

20.5
0.5

6.6


90.7
77.8
196.4

102.9

5.2
15.1

21.4


39.6
15.8

88.4
2.1
AV. STATION PRES. (mb)








961.4
964.1
967.2
965.8
967.5

RELATIVE HUMIDITY (%)
Hour 04
Hour 10 (Local Time)
Hour 16
Hour 22

37
48
47


81
75
70


80
71
61


77
62
49


75
55
42


76
52
39


74
48
35


61
38
25


59
39
25
43

68
49
31
45

80
64
49
74

83
75
68
76

82
76
73
82

75
59
47

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



49

49

49


49

49



1.28
3.55
1970
0.14
1991
1.35
1956

2.1
1957
12.8
1966


0.89
1.99
1986
0.17
1.88
0.93
1959

14.9
1956
7.5
1956


1.09
2.70
1972
0.25
1969
0.92
1981

9.7
1955
6.7
1989


1.13
3.29
1978
0.05
1956
1.06
1978

1.1
1972
1.0
1947


1.31
4.80
1948
0.27
1964
1.63
1948

T
1990
T
1990


1.25
4.70
1950
0.24
1973
1.72
1950

0.0

0.0



0.67
2.60
1987
T
1953
1.40
1964

T
1991
T
1991


0.78
2.96
1989
T
1969
1.64
1989

0.0

0.0



0.78
2.36
1947
T
1975
1.73
1955

0.0

0.0



0.90
2.79
1950
T
1987
1.19
1950

2.5
1971
1.3
1971


1.15
2.79
1973
0.23
1976
1.04
1988

14.4
1961
8.3
1961


1.20
3.28
1964
0.14
1970
1.12
1958

18.7
1968
8.4
1968


12.43
4.80
MAY 1948
T
OCT 1987
1.73
SEP 1955

26.1
JAN 1957
12.8
JAN 1966
WIND
Mean Speed (mph)
Prevailing Direction
through 1964
Fastest Mile
-Direction(!!)
-Speed(mph)
-Year
Peak Gust
-Direction(!!)
-Speed(mph)
-Date





24
24











72
1972










64
1972










60
1982










58
1985










54
1976










54
1994





5.5



29
59
1995





4.9




51
1976





5.8




59
1991





6.6




59
1991





5.3




59
1977










63
1991










72
JAN 1972




(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.