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
95.1
97
90
93
98
97
February
95.4
93
98
98
95
March
94.3
93
86
96
98
April
95.4
98
88
98
96
May
96.4
100
89
98
98
June
91.6
92
99
90
85
July
91.8
85
86
93
95
August
92.4
94
85
99
92
September
94.7
90
97
92
97
October
93.4
81
88
92
98
November
95.6
97
98
95
93
December
95.0
84
98
96
94
Average
94.5
97.3
91.1
91.6
95.2
94.7
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
18.8
19.1
17.8
17.1
19.1
19.6
February
18.6
17.3
17.6
20.3
19.3
March
19.0
18.3
17.1
19.6
19.0
April
20.4
19.1
18.8
20.6
21.0
May
20.1
19.3
18.8
19.3
20.3
June
21.7
21.6
20.5
21.3
22.3
July
24.3
24.3
23.6
22.8
24.8
August
25.6
25.6
24.6
26.0
25.3
September
25.4
24.8
23.8
27.1
25.0
October
24.1
22.5
23.3
22.8
23.6
November
21.9
21.1
22.1
20.1
22.8
December
19.0
18.8
20.0
16.8
16.5
Average
21.3
19.1
20.9
20.6
21.5
21.6
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
10.0
8.1
9.4
9.5
9.0
9.5
February
10.4
11.4
8.4
8.0
10.8
March
12.1
12.1
10.6
11.1
11.1
April
14.1
13.0
12.5
13.4
14.4
May
15.6
15.3
15.0
14.4
16.1
June
17.2
17.5
16.3
16.6
17.8
July
19.6
19.1
18.6
18.6
20.5
August
20.4
19.8
18.8
21.0
20.5
September
19.8
19.8
19.3
21.1
19.8
October
16.5
16.1
15.8
17.3
15.3
November
12.4
10.6
11.1
10.0
13.4
December
10.1
10.1
10.5
8.8
10.1
Average
14.1
8.1
14.5
13.9
14.3
15.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
5.8
1
9
13
1
4
February
5.5
11
6
3
0
March
5.4
8
13
2
5
April
1.6
1
1
1
1
May
2.0
1
1
0
2
June
0.8
0
2
1
1
July
0.0
0
0
0
0
August
0.7
0
4
0
1
September
1.3
0
5
4
1
October
0.5
0
0
1
1
November
1.8
0
1
5
0
December
3.5
0
2
6
8
Average
2.1
0.6
2.4
4.0
1.7
1.9
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
5.3
5
5
7
4
5
February
6.3
6
7
6
5
March
6.6
7
7
7
7
April
6.7
7
7
7
7
May
6.9
6
6
7
7
June
6.3
6
6
6
6
July
6.4
6
6
6
6
August
6.6
6
7
7
7
September
6.5
6
6
6
6
October
5.7
6
6
5
6
November
5.3
5
5
6
5
December
4.6
4
4
5
6
Average
6.0
4.9
5.9
6.1
6.0
6.1
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
284°
271°
230°
282°
278°
February
248°
263°
280°
276°
March
251°
250°
257°
266°
April
270°
271°
270°
271°
May
258°
260°
234°
244°
June
242°
283°
247°
260°
July
271°
272°
267°
274°
August
267°
285°
278°
278°
September
279°
278°
274°
286°
October
282°
284°
271°
278°
November
292°
279°
256°
300°
December
291°
274°
281°
260°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.