Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
71.5
68
66
63
86
67
February
79.6
70
69
76
89
81
March
85.9
82
94
72
96
92
April
89.3
85
92
95
92
May
92.9
97
83
95
94
June
93.5
94
92
94
91
July
94.0
97
95
94
93
August
86.5
97
90
77
90
September
84.9
83
78
84
83
October
77.2
79
63
75
75
November
72.3
70
83
66
75
December
77.2
55
88
82
80
Average
83.7
73.7
83.4
82.5
86.5
85.6
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-4.8
-3
-1
-4
-2
-4
February
-2.4
1
-1
1
-2
1
March
6.0
7
7
6
7
5
April
11.0
11
9
14
11
May
19.9
25
14
18
19
June
22.0
25
21
25
19
July
26.5
28
27
30
23
August
25.9
27
28
25
25
September
18.7
20
22
18
21
October
9.0
11
13
8
8
November
1.2
2
-3
2
1
December
-4.2
-1
-8
-8
-2
Average
9.9
1.4
12.8
11.2
11.3
10.4
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-9.6
-9
-5
-9
-7
-10
February
-11.7
-6
-7
-8
-11
-8
March
-6.5
-4
-9
-3
-4
-7
April
-2.2
-2
-2
-2
-4
May
3.7
5
3
3
4
June
8.0
8
8
9
8
July
9.9
10
10
11
10
August
9.4
9
12
10
9
September
6.9
6
10
7
7
October
1.4
2
6
3
2
November
-4.9
-2
-8
-2
-3
December
-8.0
-4
-12
-13
-6
Average
-1.4
-7.4
1.0
1.0
0.4
0.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
33.6
34
32
39
28
47
February
36.3
29
54
31
26
29
March
23.2
20
15
31
15
23
April
17.6
19
19
13
12
May
14.6
11
23
19
17
June
20.0
18
25
17
26
July
10.1
7
8
1
21
August
10.1
13
10
13
7
September
17.2
19
9
21
11
October
22.9
9
21
27
38
November
29.8
18
34
41
30
December
36.7
38
44
43
29
Average
22.2
27.3
20.1
22.9
20.5
22.8
Precipitation during daylight period
Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.
Wind speed (knots)
Month
Average
2024
2023
2022
2021
2020
January
1.3
1
1
2
1
2
February
2.5
2
2
2
3
2
March
2.4
3
2
2
2
4
April
2.9
2
4
4
3
May
2.7
3
3
3
3
June
2.7
3
3
2
3
July
2.6
3
3
3
2
August
2.4
2
2
2
4
September
2.1
2
2
2
2
October
2.0
2
2
2
2
November
1.8
1
4
1
1
December
1.2
1
2
3
1
Average
2.2
1.9
1.9
2.4
2.3
2.5
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2022
2021
2020
January
019°
032°
007°
310°
004°
February
033°
028°
018°
016°
196°
March
016°
054°
045°
148°
021°
April
161°
093°
047°
055°
May
118°
130°
122°
078°
June
185°
119°
085°
163°
July
142°
101°
122°
185°
August
122°
084°
123°
180°
September
113°
122°
134°
022°
October
033°
211°
027°
013°
November
197°
016°
188°
034°
December
263°
019°
266°
360°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.