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
94.5
91
95
96
96
100
February
87.1
84
89
88
88
92
March
88.8
86
85
94
97
85
April
91.2
92
91
90
91
May
93.0
97
99
88
96
June
98.5
97
100
98
99
July
98.9
100
98
100
100
August
99.3
100
99
100
September
93.1
92
100
95
October
88.5
88
90
83
November
87.6
94
88
90
December
92.0
99
89
86
Average
92.2
86.9
93.9
94.7
92.8
93.6
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
3.4
1
3
8
5
2
February
-1.2
3
3
3
-6
6
March
5.8
6
1
10
11
6
April
10.9
12
9
12
11
May
16.8
21
16
15
17
June
22.7
22
23
26
22
July
28.1
29
30
31
27
August
28.9
28
31
29
September
22.6
23
25
23
October
11.2
13
16
7
November
5.4
10
0
8
December
3.8
8
-6
5
Average
10.1
3.1
14.4
14.4
11.5
13.8
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
-10
-5
-4
-2
-8
February
-11.5
-6
-6
-9
-15
-6
March
-6.5
-5
-7
-3
-3
-6
April
-1.1
0
-3
0
-2
May
4.8
8
4
3
5
June
9.1
9
8
10
9
July
12.0
12
13
13
11
August
12.3
13
13
12
September
8.7
9
11
8
October
1.0
2
6
-1
November
-4.2
-1
-9
-1
December
-6.7
-2
-15
-4
Average
-2.9
-8.6
2.6
1.8
-1.5
1.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.3
13
8
15
7
3
February
22.8
21
13
20
30
12
March
11.8
11
20
12
5
12
April
15.5
17
15
16
14
May
10.7
10
5
16
8
June
6.2
5
7
5
10
July
1.4
1
2
1
2
August
1.8
4
0
1
September
7.4
9
6
3
October
13.9
13
10
24
November
12.9
5
20
8
December
9.0
2
29
8
Average
11.1
15.1
8.7
10.2
12.5
8.3
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
11.3
10
11
13
14
11
February
11.2
10
14
14
9
13
March
9.2
8
8
10
11
12
April
10.2
10
11
11
9
May
8.0
6
11
8
9
June
7.6
6
10
7
8
July
6.5
6
7
5
7
August
6.7
7
7
6
September
8.2
8
8
9
October
9.7
8
9
12
November
11.8
10
12
15
December
11.0
12
9
10
Average
9.6
9.0
8.6
9.8
9.3
9.7
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
251°
277°
236°
229°
224°
February
246°
268°
258°
256°
245°
March
228°
248°
267°
233°
265°
April
261°
265°
275°
270°
May
256°
259°
268°
247°
June
262°
252°
275°
253°
July
255°
240°
161°
219°
August
257°
267°
234°
September
245°
264°
253°
October
241°
271°
244°
November
255°
268°
232°
December
265°
264°
218°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.