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
92.1
82
95
96
91
96
February
86.3
77
83
89
90
95
March
87.1
80
78
86
96
86
April
92.5
95
87
94
92
May
94.1
90
96
90
99
June
97.8
97
93
100
99
July
93.3
90
92
90
97
August
93.2
93
96
95
100
September
91.9
91
96
98
97
October
89.4
82
90
95
88
November
89.8
99
79
93
94
December
91.4
94
92
88
87
Average
90.7
79.4
90.1
90.9
93.5
94.2
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
-2.8
-4
0
1
0
-4
February
-4.6
1
0
1
-8
1
March
2.9
2
-1
7
8
1
April
9.1
11
8
12
7
May
17.3
22
15
15
15
June
20.9
23
18
24
19
July
24.1
24
25
26
23
August
24.4
25
27
24
25
September
18.3
19
22
20
20
October
10.9
11
16
13
8
November
3.4
7
-2
7
5
December
-2.3
5
-8
-8
2
Average
9.1
-1.3
12.1
11.3
11.1
10.0
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
-13.7
-15
-10
-11
-10
-15
February
-15.1
-10
-11
-11
-19
-10
March
-11.9
-10
-15
-7
-6
-11
April
-5.7
-4
-6
-5
-5
May
2.8
6
1
1
2
June
6.4
7
5
8
7
July
8.3
8
8
11
8
August
7.9
9
9
9
7
September
3.7
4
5
4
5
October
-3.0
-2
0
-4
-4
November
-8.1
-6
-12
-6
-7
December
-13.7
-7
-20
-19
-9
Average
-4.0
-12.0
-2.3
-3.3
-3.0
-3.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.5
17
14
11
12
3
February
17.8
22
28
17
12
7
March
16.3
33
23
16
6
18
April
15.4
17
31
12
16
May
11.0
9
9
19
17
June
10.1
12
18
6
12
July
3.8
6
6
1
2
August
4.2
8
4
6
1
September
6.0
9
6
3
2
October
10.9
21
10
6
19
November
13.2
6
26
4
14
December
12.2
15
26
17
7
Average
11.9
24.5
13.8
14.6
8.5
9.8
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
7.6
6
7
11
9
6
February
7.9
7
9
10
8
8
March
7.9
6
6
10
9
9
April
8.3
8
9
9
8
May
8.2
7
10
9
7
June
8.9
9
10
9
9
July
6.9
7
6
7
7
August
7.0
8
7
7
8
September
7.3
7
7
8
8
October
8.3
8
7
9
8
November
8.3
8
9
10
9
December
7.5
7
7
7
8
Average
7.7
6.4
7.5
8.7
8.5
7.9
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
306°
316°
289°
282°
264°
February
331°
273°
283°
286°
284°
March
101°
343°
302°
273°
294°
April
216°
341°
290°
293°
May
117°
294°
221°
283°
June
323°
316°
287°
305°
July
353°
137°
152°
296°
August
360°
333°
301°
253°
September
233°
325°
257°
306°
October
293°
278°
259°
252°
November
287°
331°
272°
284°
December
264°
323°
307°
288°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.