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
2025
2024
2023
2022
2021
January
88.9
94
80
90
88
97
February
86.0
89
92
92
83
77
March
87.6
83
88
84
90
April
89.3
87
82
96
93
May
87.8
91
96
84
92
June
94.4
98
87
97
97
July
95.7
96
96
100
92
August
96.7
91
97
99
98
September
92.8
93
80
97
96
October
89.0
100
89
85
95
November
95.4
95
99
94
100
December
86.1
83
82
89
90
Average
91.1
91.3
91.1
89.9
91.6
93.3
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
2025
2024
2023
2022
2021
January
5.5
3.3
6.2
10.0
2.7
4.7
February
8.0
5.9
8.8
10.0
8.0
3.7
March
11.3
13.4
11.8
12.8
12.8
April
17.2
17.8
19.8
16.3
18.1
May
22.9
24.1
23.0
23.8
24.0
June
28.3
30.6
26.6
29.0
30.0
July
31.1
31.6
31.5
32.8
30.5
August
29.5
29.6
28.6
31.3
30.5
September
25.8
25.3
25.6
25.5
26.8
October
20.3
21.8
21.3
18.1
22.1
November
13.4
16.0
13.0
15.3
13.3
December
8.0
7.2
10.5
8.3
11.0
Average
17.0
4.5
19.4
19.4
19.0
19.0
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2025
2024
2023
2022
2021
January
-2.6
-4.7
0.5
3.7
-6.7
-2.3
February
-1.8
-2.9
0.7
0.7
-3.9
-3.7
March
2.7
4.7
3.1
3.1
3.0
April
8.0
8.6
9.8
7.9
7.5
May
13.3
14.8
12.3
14.5
12.9
June
18.5
20.3
17.3
18.8
19.5
July
22.3
23.1
22.6
23.3
21.8
August
21.1
20.3
20.8
22.1
22.5
September
17.4
16.8
17.8
16.5
18.8
October
11.7
11.3
12.3
9.4
14.1
November
4.8
7.5
4.0
6.7
4.5
December
1.3
0.3
4.0
2.0
3.9
Average
8.7
-3.7
10.8
10.7
10.0
10.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
13.6
7
25
15
16
5
February
14.5
11
10
9
20
26
March
14.1
18
15
13
9
April
12.4
15
12
10
10
May
12.5
14
5
13
13
June
5.6
1
6
6
6
July
4.7
6
5
2
4
August
6.3
9
7
2
6
September
9.0
8
23
7
5
October
11.2
0
12
17
6
November
8.3
8
3
9
6
December
14.3
17
15
20
6
Average
10.1
8.9
10.4
10.2
10.2
8.3
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
2025
2024
2023
2022
2021
January
10.2
11
9
9
10
11
February
9.6
10
9
9
10
9
March
10.7
11
11
11
10
April
10.0
10
9
11
10
May
8.4
8
8
8
9
June
8.4
9
8
8
8
July
7.5
7
7
8
7
August
7.6
7
8
8
7
September
8.2
7
9
8
9
October
8.6
8
8
9
8
November
9.4
10
8
10
9
December
9.1
9
8
10
8
Average
9.1
10.8
8.6
8.4
9.1
8.8
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2025
2024
2023
2022
2021
January
279°
298°
288°
298°
308°
February
295°
312°
284°
284°
324°
March
314°
305°
284°
295°
April
316°
258°
295°
293°
May
127°
279°
050°
304°
June
247°
324°
257°
229°
July
195°
213°
242°
268°
August
253°
274°
221°
230°
September
030°
360°
291°
283°
October
306°
286°
341°
302°
November
287°
285°
276°
283°
December
288°
293°
316°
280°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.