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
79.0
76
71
63
86
87
February
80.7
86
80
79
83
80
March
79.0
67
76
71
85
86
April
79.6
71
81
92
88
May
87.9
91
83
94
91
June
82.9
64
82
95
84
July
84.4
69
96
77
82
August
85.7
77
83
82
95
September
86.1
84
82
86
85
October
80.2
79
72
85
86
November
84.1
87
81
94
84
December
75.1
55
72
72
78
Average
81.9
75.5
75.2
79.6
86.1
85.7
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
-1.8
0
2
-1
0
1
February
1.4
3
2
2
-1
1
March
5.2
7
6
7
7
7
April
11.8
13
13
14
10
May
19.0
20
22
19
19
June
23.5
22
23
26
24
July
26.6
27
29
23
27
August
25.8
24
27
27
26
September
22.1
23
21
22
22
October
15.5
17
17
17
14
November
7.4
7
11
9
10
December
1.9
4
5
3
3
Average
12.2
3.4
14.1
14.9
13.8
13.5
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
-8.2
-6
-4
-11
-7
-7
February
-8.7
-5
-8
-8
-8
-7
March
-4.8
-1
-2
-2
-4
-2
April
2.5
4
3
3
1
May
7.8
9
9
8
7
June
13.1
13
13
15
13
July
16.8
19
18
14
18
August
16.4
16
18
18
16
September
12.4
14
12
14
11
October
7.1
10
7
9
5
November
-1.5
-1
2
1
1
December
-6.9
-2
-2
-4
-4
Average
3.3
-4.0
5.6
5.1
4.9
4.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
14.8
22
19
19
15
8
February
12.8
7
14
20
13
14
March
12.8
23
16
17
5
9
April
13.8
11
22
12
16
May
7.3
6
5
8
4
June
8.3
16
7
3
6
July
6.5
11
4
14
3
August
5.8
12
6
6
3
September
5.8
6
11
8
2
October
11.9
12
12
11
10
November
12.3
10
14
7
11
December
14.7
18
21
16
13
Average
10.8
17.6
12.2
12.0
9.3
7.8
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
7.0
7
7
8
7
5
February
7.1
8
6
8
7
7
March
8.2
8
8
7
8
8
April
7.9
7
8
9
9
May
7.1
8
6
7
8
June
6.0
6
6
6
6
July
5.3
5
6
6
5
August
5.3
5
5
5
5
September
5.7
5
5
6
7
October
6.1
5
5
6
7
November
6.5
6
6
6
6
December
6.5
6
9
6
7
Average
6.6
7.6
6.1
6.5
6.5
6.7
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
347°
338°
326°
341°
318°
February
317°
331°
305°
319°
302°
March
329°
331°
294°
281°
320°
April
172°
314°
337°
325°
May
310°
158°
314°
280°
June
046°
232°
234°
257°
July
167°
256°
340°
198°
August
236°
353°
145°
282°
September
344°
313°
268°
250°
October
292°
127°
352°
302°
November
303°
276°
289°
281°
December
345°
335°
313°
297°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.