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
77.8
75
70
91
79
64
February
87.9
92
90
90
84
93
March
87.6
92
83
89
86
86
April
90.5
94
90
89
94
95
May
95.3
97
96
97
95
June
97.6
96
99
99
100
July
97.0
99
97
92
100
August
95.5
95
95
98
99
September
94.3
94
97
96
97
October
90.9
87
100
91
92
November
92.6
99
91
99
90
December
81.5
80
51
90
89
Average
91.0
88.5
91.0
93.5
92.4
92.3
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
-5.7
-4
-4
-6
-2
-5
February
-3.5
6
-2
-4
-9
-3
March
4.8
9
1
5
10
7
April
12.2
15
12
9
14
13
May
20.9
23
21
21
19
June
27.6
29
28
30
29
July
28.0
28
29
29
28
August
26.3
28
27
28
27
September
23.6
26
25
25
21
October
13.9
15
17
17
11
November
5.8
10
5
8
9
December
-1.3
6
-5
1
-2
Average
12.3
6.3
14.6
13.9
14.3
13.3
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
-13.5
-11
-12
-18
-9
-12
February
-13.4
-5
-13
-16
-16
-13
March
-4.0
-3
-8
-3
-1
-1
April
1.7
4
2
1
3
1
May
9.6
11
10
9
9
June
16.1
16
16
17
16
July
17.3
15
17
18
19
August
15.6
16
16
15
16
September
12.1
13
11
12
9
October
3.8
6
3
8
1
November
-4.6
-2
-3
-2
-1
December
-9.4
-3
-9
-9
-11
Average
2.2
-4.2
3.9
3.0
3.7
3.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
9.8
5
14
7
9
17
February
9.7
6
11
8
7
8
March
8.8
5
14
6
12
7
April
9.7
8
12
11
5
5
May
7.9
8
6
9
8
June
4.3
4
4
4
1
July
3.3
1
2
4
3
August
3.0
4
2
1
2
September
4.9
2
4
5
5
October
7.8
6
4
7
9
November
6.5
2
13
3
7
December
12.2
12
47
10
10
Average
7.0
6.0
6.9
6.3
6.0
6.3
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
9.1
9
8
10
8
9
February
9.5
10
10
12
9
8
March
9.7
11
10
10
10
9
April
10.8
13
12
14
11
9
May
8.5
9
10
9
9
June
8.2
7
10
7
9
July
6.4
6
8
5
6
August
6.7
7
7
8
7
September
8.0
7
8
8
8
October
9.5
9
10
8
10
November
10.1
10
12
11
10
December
9.1
9
12
10
11
Average
8.9
10.6
8.5
9.9
8.5
8.5
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
287°
293°
271°
305°
277°
February
262°
265°
299°
277°
271°
March
322°
322°
326°
190°
282°
April
303°
294°
277°
312°
310°
May
120°
229°
217°
340°
June
150°
234°
241°
171°
July
273°
255°
182°
210°
August
208°
198°
186°
189°
September
160°
208°
225°
246°
October
294°
254°
203°
279°
November
251°
264°
271°
233°
December
259°
298°
264°
244°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.