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
80.1
59
70
75
93
89
February
93.4
90
89
98
93
95
March
91.3
91
66
97
99
96
April
97.0
98
96
92
100
96
May
98.5
100
98
99
98
June
98.6
94
97
99
100
July
99.3
100
99
99
100
August
97.1
97
100
98
98
September
94.8
97
99
87
86
October
97.2
97
100
96
96
November
92.5
92
79
96
98
December
80.3
69
59
91
90
Average
92.9
83.8
88.7
92.1
96.0
95.2
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
2.2
4
1
2
4
4
February
5.0
8
2
8
5
8
March
9.6
10
3
14
12
11
April
15.0
17
13
13
18
17
May
20.7
22
19
21
21
June
25.9
24
25
31
26
July
32.9
33
34
35
32
August
31.4
30
34
32
32
September
25.7
24
29
27
29
October
17.3
18
21
17
20
November
8.3
9
3
11
9
December
2.1
5
-3
4
3
Average
15.5
9.5
15.4
17.2
18.0
17.6
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
-8.2
-5
-11
-8
-5
-5
February
-6.0
-2
-10
-7
-5
-5
March
-4.4
-3
-8
-3
-4
-3
April
-1.1
-1
-1
-3
-3
-1
May
3.8
7
2
3
3
June
7.0
8
7
9
8
July
10.2
11
11
13
9
August
9.4
11
12
9
9
September
3.6
4
6
2
3
October
-3.9
-1
-1
1
-2
November
-6.1
-4
-10
-2
-6
December
-8.1
-3
-14
-7
-9
Average
-1.7
-3.5
0.2
-1.8
1.0
0.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.2
26
12
6
8
13
February
9.6
12
13
3
9
6
March
12.1
10
37
6
3
7
April
7.5
2
9
14
3
7
May
6.6
9
7
4
5
June
3.5
2
5
0
3
July
0.3
0
0
1
0
August
1.1
5
1
0
0
September
1.7
1
2
3
0
October
3.7
2
2
6
3
November
6.2
9
4
5
5
December
9.3
16
12
13
8
Average
6.7
12.7
9.8
4.9
4.0
4.4
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
2024
2023
2022
2021
2020
January
4.9
6
5
4
5
5
February
6.9
7
6
5
7
7
March
7.2
7
8
7
7
7
April
8.0
7
7
9
7
7
May
7.1
6
8
8
7
June
6.4
5
7
7
7
July
5.3
5
5
5
6
August
5.3
5
5
6
5
September
5.2
5
5
5
5
October
5.7
6
5
7
6
November
5.2
5
5
5
6
December
4.3
5
3
5
5
Average
6.1
6.7
5.6
5.9
6.1
6.1
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
284°
055°
237°
058°
263°
February
252°
255°
321°
284°
288°
March
244°
073°
296°
287°
269°
April
284°
283°
271°
301°
282°
May
246°
276°
295°
244°
June
268°
266°
236°
287°
July
245°
269°
255°
244°
August
269°
235°
276°
257°
September
267°
220°
254°
255°
October
270°
253°
242°
274°
November
314°
238°
236°
262°
December
133°
341°
239°
063°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.