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
91.5
86
93
86
96
96
February
81.1
70
80
83
92
94
March
85.4
72
85
91
95
74
April
89.2
82
89
92
89
May
93.1
96
97
94
95
June
99.3
98
100
100
100
July
95.7
97
95
82
100
August
94.8
97
99
93
99
September
92.3
92
98
100
97
October
89.3
76
90
97
88
November
89.7
100
79
99
87
December
87.3
86
69
88
90
Average
89.6
74.8
90.0
90.5
93.8
92.7
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
-1.8
-2
2
1
2
-2
February
-3.0
1
1
1
-7
3
March
3.2
2
-1
6
9
2
April
9.6
11
8
11
8
May
17.3
21
14
15
15
June
21.2
23
19
24
19
July
26.4
28
27
29
24
August
26.2
27
29
24
26
September
19.5
20
23
20
22
October
10.9
11
16
12
10
November
3.7
6
-2
7
5
December
0.0
5
-8
-4
3
Average
10.0
0.1
12.9
11.8
12.0
11.2
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
-9.7
-12
-5
-9
-6
-10
February
-12.0
-8
-7
-9
-16
-7
March
-8.7
-8
-11
-5
-4
-9
April
-2.1
-1
-4
-2
-3
May
4.0
6
4
3
4
June
8.2
9
7
9
9
July
9.2
9
11
10
8
August
9.5
10
11
10
9
September
6.2
7
7
7
6
October
0.0
1
3
1
-2
November
-5.9
-1
-9
-2
-2
December
-9.9
-2
-17
-15
-4
Average
-2.6
-10.6
1.3
-1.8
-1.6
0.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.0
26
13
26
12
10
February
28.3
38
28
27
22
14
March
20.2
38
26
9
6
28
April
18.0
32
23
16
15
May
11.7
10
15
14
14
June
7.6
9
14
5
11
July
3.7
5
8
1
2
August
3.2
5
2
10
0
September
6.7
9
9
1
2
October
13.1
26
15
4
19
November
17.1
8
39
2
20
December
19.5
11
55
28
9
Average
14.9
34.4
15.5
19.0
9.4
11.6
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
13.9
13
15
18
16
2
February
11.9
11
17
16
12
5
March
10.5
9
9
15
15
4
April
11.8
11
13
13
9
May
10.1
8
14
9
11
June
10.0
9
12
11
11
July
8.9
9
8
8
11
August
9.3
10
9
10
11
September
10.9
10
10
14
12
October
12.7
10
12
13
13
November
15.4
15
13
20
17
December
13.7
14
11
12
16
Average
11.3
10.9
10.9
12.3
12.5
10.1
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
253°
259°
257°
260°
258°
February
257°
257°
253°
252°
256°
March
235°
261°
255°
255°
263°
April
257°
256°
258°
260°
May
262°
262°
258°
259°
June
257°
262°
253°
262°
July
264°
259°
248°
255°
August
251°
261°
261°
253°
September
261°
265°
253°
257°
October
262°
264°
257°
255°
November
261°
268°
258°
256°
December
262°
249°
253°
264°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.