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
90.7
93
83
93
93
89
February
86.3
87
94
92
91
75
March
89.7
95
86
92
92
89
April
91.0
88
90
83
94
May
88.5
85
87
99
82
97
June
91.1
87
99
87
81
91
July
94.3
98
97
81
99
August
92.6
93
97
88
95
September
84.5
80
89
75
96
October
90.0
95
97
88
88
November
92.2
98
98
81
100
December
85.9
86
80
85
95
Average
89.8
88.9
90.5
92.7
84.7
92.7
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
2025
2024
2023
2022
2021
January
6.1
2.7
6.7
9.6
3.6
5.4
February
9.8
7.2
10.8
12.5
10.5
4.5
March
14.0
16.8
15.1
13.5
15.5
14.4
April
19.6
20.1
22.1
18.3
18.6
May
23.6
22.8
24.3
22.6
23.8
22.6
June
28.5
29.8
30.3
26.8
28.3
27.6
July
31.4
32.6
32.2
30.8
29.6
August
29.8
29.8
30.0
30.6
29.5
September
25.8
24.8
26.5
25.8
26.3
October
20.4
21.1
20.8
18.3
22.0
November
13.1
15.4
14.0
14.9
12.6
December
8.3
7.2
9.6
7.7
12.5
Average
19.0
15.9
19.9
20.1
19.4
18.9
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
-2.5
-5.5
-2.3
2.1
-4.5
-2.3
February
0.4
-1.1
0.9
2.2
-2.8
-2.1
March
3.0
4.7
4.5
2.6
3.2
3.1
April
7.8
9.3
8.9
6.7
6.0
May
12.6
13.8
14.4
10.5
13.5
9.4
June
16.8
18.8
18.6
15.8
17.1
15.4
July
20.0
21.6
20.8
20.6
17.3
August
18.3
19.1
19.6
19.3
16.0
September
15.3
15.0
16.0
16.0
16.3
October
9.0
8.4
10.1
7.5
13.0
November
3.1
6.2
2.2
5.4
2.2
December
0.1
-1.9
0.4
0.8
2.3
Average
8.6
6.4
9.7
9.3
9.1
8.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
7.4
11
16
9
6
4
February
6.4
8
6
6
6
14
March
5.3
2
9
10
4
5
April
5.9
7
8
9
5
May
7.7
14
11
5
10
9
June
3.8
6
0
7
3
6
July
3.0
2
1
6
2
August
2.8
3
2
4
4
September
5.7
9
7
0
6
October
2.5
1
5
0
5
November
4.7
4
5
3
4
December
6.6
7
9
11
3
Average
5.3
8.0
6.1
5.9
4.9
5.4
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
7.7
8
7
7
7
8
February
6.9
9
7
8
8
7
March
8.0
9
8
9
9
8
April
7.6
7
7
7
8
May
5.7
6
5
5
5
6
June
5.4
4
6
6
6
5
July
4.6
5
5
4
5
August
4.5
5
6
5
4
September
5.0
5
5
5
6
October
5.6
6
5
6
6
November
6.8
7
6
7
7
December
5.9
6
5
6
5
Average
6.1
6.8
5.9
6.0
6.1
6.0
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
302°
315°
300°
321°
328°
February
306°
302°
290°
265°
329°
March
267°
319°
311°
267°
311°
April
271°
276°
306°
306°
May
299°
321°
005°
041°
324°
June
265°
253°
324°
295°
246°
July
206°
279°
264°
285°
August
304°
321°
263°
255°
September
067°
002°
332°
301°
October
323°
318°
334°
304°
November
305°
308°
284°
313°
December
280°
301°
310°
252°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.