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
81.9
76
77
78
86
87
February
85.2
92
81
77
86
81
March
87.9
80
80
87
97
97
April
93.9
94
93
92
98
May
96.5
98
95
98
99
June
94.5
84
94
99
97
July
96.1
90
97
94
96
August
95.9
91
93
97
98
September
93.7
88
83
97
99
October
92.4
87
99
88
95
November
91.8
93
92
95
99
December
84.0
65
80
87
89
Average
90.9
82.3
86.1
89.7
93.6
95.0
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
-1.1
0
2
-4
-2
1
February
1.6
4
2
1
-1
1
March
5.6
8
5
7
8
8
April
13.1
16
13
15
11
May
20.7
21
23
21
20
June
25.4
25
25
28
26
July
28.3
29
29
25
30
August
27.0
25
28
28
27
September
22.7
23
21
23
22
October
16.4
17
17
17
15
November
7.4
7
10
8
11
December
2.4
5
3
4
3
Average
12.9
3.9
14.6
14.8
14.5
14.7
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
-8.0
-6
-4
-15
-7
-6
February
-8.8
-5
-8
-9
-9
-7
March
-4.9
0
-3
-3
-3
-1
April
3.3
5
3
4
2
May
9.5
8
11
10
9
June
14.7
15
15
17
15
July
18.2
19
18
17
20
August
17.3
16
18
19
17
September
13.2
14
13
14
12
October
7.8
9
6
9
6
November
0.1
0
3
0
3
December
-5.5
-1
-2
-3
-3
Average
4.0
-4.5
5.9
5.0
5.7
5.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
24.9
34
29
28
21
19
February
21.3
12
27
30
19
26
March
18.6
22
32
18
7
10
April
17.0
16
19
20
11
May
9.9
10
11
6
6
June
9.0
15
12
4
6
July
7.7
14
5
13
5
August
6.5
15
6
8
7
September
8.1
10
15
6
5
October
13.5
19
5
16
14
November
15.4
10
17
14
12
December
23.2
29
32
20
19
Average
14.7
22.7
18.4
14.9
11.9
10.6
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
7.6
7
7
9
7
7
February
8.7
9
9
11
7
8
March
8.8
8
8
9
10
9
April
8.3
8
9
8
9
May
7.6
8
7
7
9
June
7.2
6
8
8
7
July
6.4
6
7
6
7
August
6.4
7
6
6
6
September
6.6
5
6
8
8
October
7.5
7
7
6
9
November
8.4
8
9
7
10
December
7.3
6
7
8
9
Average
7.6
8.0
6.9
7.8
7.2
7.9
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
275°
331°
300°
338°
211°
February
257°
246°
234°
272°
247°
March
304°
323°
268°
253°
221°
April
223°
310°
315°
293°
May
304°
239°
282°
275°
June
327°
255°
205°
239°
July
213°
230°
285°
215°
August
215°
231°
200°
252°
September
305°
297°
212°
213°
October
225°
210°
225°
200°
November
228°
225°
238°
214°
December
271°
276°
237°
228°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.