Washington-National Airport, D.C.
H
I S T O R I C A L
W
E A T H E R
D
A T A
Average Temperature
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
°F
58
34.6
37.5
47.2
56.5
66.4
75.6
80
78.5
71.3
59.7
49.8
39.4
°C
14
1
3
8
13
19
24
26
25
21
15
9
4
Years Charted: 30
Source:
National Weather Service, San Francisco
Results based on data collected from 1961 - 1990
Average High Temperature
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
°F
66.9
42.3
45.9
56.5
66.7
76.2
84.7
88.5
86.9
80.1
69.1
58.3
47
°C
19
5
7
13
19
24
29
31
30
26
20
14
8
Years Charted: 30
Source:
National Weather Service, San Francisco
Results based on data collected from 1961 - 1990
Average Low Temperature
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
°F
49.2
26.8
29.1
37.7
46.4
56.6
66.5
71.4
70
62.5
50.3
41.1
31.7
°C
9
-2
-1
3
8
13
19
21
21
16
10
5
0
Years Charted: 30
Source:
National Weather Service, San Francisco
Results based on data collected from 1961 - 1990
Highest Recorded Temperature
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
°F
104
79
82
89
95
99
101
104
103
101
94
86
75
°C
40
26
27
31
35
37
38
40
39
38
34
30
23
Years Charted: 52
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Lowest Recorded Temperature
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
°F
-5
-5
4
11
24
34
47
54
49
39
29
16
1
°C
-20
-20
-15
-11
-4
1
8
12
9
3
-1
-8
-17
Years Charted: 52
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Mean Number of Days Below 32°F/0°C
Total
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Days
70
22
18
9
1
0
0
0
0
0
---
4
16
Years Charted: 33
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Average Precipitation
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
in.
38.63
2.72
2.71
3.17
2.71
3.66
3.38
3.8
3.91
3.31
3.02
3.12
3.12
mm
981
69
68
80
68
92
85
96
99
84
76
79
79
Years Charted: 30
Source:
National Weather Service, San Francisco
Results based on data collected from 1961 - 1990
Average Snowfall
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
in.
16.6
5.3
5.3
2.1
0
0
0
0
0
0
0
0.8
3.1
mm
421
134
134
53
0
0
0
0
0
0
0
20
78
Years Charted: 50
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Average Wind Speed
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
mph
9.4
10
10.4
10.9
10.5
9.3
8.9
8.3
8.1
8.4
8.7
9.3
9.6
km/h
15
16
16
17
16
14
14
13
13
13
13
14
15
Years Charted: 45
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Average Days of Precipitation
Total
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Days
112
10
9
11
10
11
9
10
9
8
7
9
9
Years Charted: 52
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Days With Sunshine
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
%
56
47
51
55
56
58
64
62
62
61
59
51
46
Years Charted: 45
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Mean Number of Cloudy Days
Total
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Days
163
16
14
15
14
14
11
12
12
12
12
14
16
Years Charted: 45
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Mean Number of Partly Cloudy Days
Total
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Days
105
7
7
9
9
10
11
12
10
8
8
8
7
Years Charted: 45
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Mean Number of Clear Days
Total
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Days
97
8
7
7
7
7
8
7
9
10
11
8
8
Years Charted: 45
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Average Morning Relative Humidity
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
%
74
70
70
70
70
74
75
76
80
81
80
75
72
Years Charted: 33
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
Average Afternoon Relative Humidity
Year
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
%
53
55
52
50
49
52
52
53
55
56
53
54
57
Years Charted: 33
Source:
National Weather Service, San Francisco
Results based on data collected through 1993
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