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
89.8
86
97
77
82
92
February
84.6
81
81
92
88
89
March
91.4
96
92
92
86
89
April
92.6
89
92
100
92
May
91.4
94
100
84
91
89
June
97.8
97
97
94
99
100
July
98.1
100
96
98
100
August
96.9
93
99
98
97
September
96.8
99
98
94
100
October
93.3
98
91
94
100
November
91.4
84
97
92
100
December
95.4
100
96
94
98
Average
93.3
91.4
94.1
92.2
93.2
95.4
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
6.3
3.9
5.5
1.3
7.5
7.7
February
7.3
8.1
10.5
6.5
6.0
3.6
March
12.9
16.0
13.0
9.9
12.9
10.8
April
17.6
18.1
17.6
18.6
16.1
May
21.7
21.8
21.1
21.6
23.3
20.5
June
29.2
28.6
32.1
24.1
29.8
30.0
July
32.4
32.7
30.8
33.6
32.5
August
31.6
32.1
31.1
31.8
32.2
September
28.4
29.3
28.3
29.1
28.8
October
19.1
23.8
19.6
19.1
20.5
November
12.8
9.9
14.4
9.5
16.8
December
9.3
11.6
10.5
8.1
12.0
Average
18.7
15.7
20.0
18.0
19.5
19.4
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
-7.5
-9.0
-9.8
-8.2
-7.2
-5.2
February
-7.5
-7.2
-3.3
-7.9
-8.0
-10.5
March
-2.5
0.7
-2.5
-5.9
-3.2
-2.5
April
1.9
3.5
1.0
1.5
1.3
May
7.3
7.2
7.2
9.0
6.7
7.7
June
13.4
13.3
14.6
12.0
13.4
14.6
July
16.8
16.1
16.1
17.6
17.3
August
16.1
16.6
16.3
17.3
16.6
September
12.4
13.6
12.0
12.9
13.3
October
4.1
8.0
4.0
5.5
5.0
November
-2.6
-2.3
-1.6
-4.0
1.1
December
-5.5
-3.6
-3.2
-7.2
-4.5
Average
4.0
1.2
5.3
4.1
4.3
4.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2025
2024
2023
2022
2021
January
9.0
14
7
16
15
5
February
11.8
12
15
9
14
10
March
7.3
2
11
5
17
11
April
7.1
11
9
0
8
May
6.1
5
3
8
6
7
June
2.2
1
1
9
2
1
July
1.0
1
1
1
1
August
1.4
1
1
3
1
September
1.7
1
1
4
1
October
4.2
1
5
3
1
November
6.9
17
7
9
1
December
4.1
1
3
6
2
Average
5.2
6.3
5.5
6.1
6.3
3.8
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
2025
2024
2023
2022
2021
January
8.2
9
8
7
8
8
February
9.1
9
8
10
8
9
March
9.9
10
8
10
10
9
April
9.8
9
9
12
9
May
9.0
9
10
8
11
8
June
8.4
8
10
8
9
7
July
7.8
8
8
8
7
August
7.6
8
8
8
7
September
7.8
8
8
7
8
October
8.2
9
8
7
9
November
8.2
8
8
8
8
December
8.8
8
9
11
9
Average
8.6
9.1
8.6
8.4
8.8
8.1
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
023°
295°
132°
004°
360°
February
082°
285°
258°
157°
309°
March
306°
345°
066°
354°
183°
April
308°
328°
302°
006°
May
007°
219°
024°
266°
110°
June
166°
229°
138°
179°
155°
July
309°
032°
325°
014°
August
239°
140°
318°
300°
September
184°
256°
217°
034°
October
314°
038°
286°
106°
November
231°
109°
125°
268°
December
250°
310°
257°
232°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.