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
92.5
94
92
93
93
95
February
84.4
90
89
87
77
87
March
88.1
83
81
90
95
89
April
87.9
90
90
85
90
May
93.9
97
100
89
98
June
98.3
99
99
99
96
July
99.2
100
100
100
100
August
98.7
99
100
100
99
September
94.4
94
99
100
96
October
87.9
89
93
74
November
90.5
96
86
100
December
93.3
97
87
92
Average
92.3
88.7
93.5
93.8
93.5
93.5
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
3.7
1
3
7
5
3
February
-1.6
4
5
3
-7
3
March
6.7
5
12
8
10
5
April
10.3
14
8
11
9
May
15.4
19
15
15
16
June
21.5
20
21
26
21
July
27.1
27
28
30
26
August
26.8
26
30
26
28
September
21.4
22
21
24
23
October
11.4
12
16
9
November
6.2
10
2
9
December
4.6
9
-3
6
Average
10.8
3.3
15.0
13.0
15.4
13.7
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
-7.8
-11
-5
-4
-3
-7
February
-11.8
-5
-5
-11
-14
-6
March
-5.4
-5
-4
-3
-3
-6
April
-1.1
1
-3
-1
-3
May
4.7
8
4
3
4
June
9.4
10
9
11
9
July
13.0
13
14
16
12
August
13.1
14
16
12
13
September
7.8
10
0
9
8
October
0.4
1
4
-1
November
-5.7
-1
-8
-2
December
-6.6
-3
-13
-3
Average
-1.7
-7.0
3.1
0.9
3.5
2.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.5
11
13
14
12
10
February
21.8
15
14
19
32
19
March
13.6
14
16
16
8
16
April
18.2
18
17
23
15
May
9.4
8
9
9
4
June
7.4
8
8
3
12
July
2.5
1
3
2
2
August
4.0
7
3
5
1
September
8.3
8
12
3
5
October
15.8
12
11
34
November
14.0
5
18
0
December
8.5
5
26
1
Average
11.1
13.4
9.4
12.1
10.0
9.6
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
10.9
9
11
13
13
11
February
11.1
9
12
15
11
12
March
9.4
7
9
13
10
11
April
11.2
10
14
11
11
May
9.1
8
10
9
10
June
8.8
7
10
9
9
July
7.2
7
8
7
7
August
8.3
8
9
10
8
September
9.0
8
8
10
10
October
9.6
7
10
13
November
10.3
9
11
15
December
9.4
8
9
8
Average
9.6
8.4
8.4
11.0
9.7
10.0
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
278°
286°
284°
276°
268°
February
273°
277°
290°
293°
280°
March
311°
312°
300°
279°
279°
April
289°
292°
300°
305°
May
314°
294°
316°
280°
June
261°
281°
316°
298°
July
293°
327°
355°
302°
August
269°
288°
302°
306°
September
267°
312°
293°
300°
October
295°
286°
283°
November
276°
284°
270°
December
268°
288°
283°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.