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
59.3
52
36
78
68
51
February
62.0
58
54
74
58
62
March
67.6
63
52
69
73
66
April
82.0
78
84
90
82
May
88.4
92
82
89
93
June
95.5
91
99
96
94
July
99.3
100
98
100
100
August
97.4
98
97
100
100
September
92.2
93
90
88
99
October
82.5
83
81
71
93
November
79.6
79
75
85
82
December
64.1
71
51
59
68
Average
77.9
57.8
78.7
83.6
80.4
77.7
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
-4.6
-2
-3
-3
-4
-4
February
-4.6
-2
-4
-4
-3
-1
March
-1.4
0
-4
1
0
0
April
2.9
2
3
4
3
May
8.6
9
8
9
10
June
14.9
13
17
18
14
July
19.5
21
19
20
16
August
17.9
19
18
17
20
September
14.6
14
15
15
13
October
6.2
7
6
5
9
November
0.3
1
-2
2
1
December
-3.9
-1
-4
-3
-2
Average
4.3
-2.4
6.1
6.5
5.8
3.8
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
-10.6
-9
-10
-10
-11
-9
February
-11.4
-10
-12
-12
-11
-10
March
-8.3
-7
-11
-8
-8
-7
April
-5.4
-7
-6
-4
-5
May
0.6
1
-1
0
1
June
6.2
4
6
8
7
July
10.1
10
10
10
16
August
9.4
8
9
15
20
September
5.6
4
7
6
5
October
-2.2
0
-1
-2
0
November
-6.2
-5
-10
-4
-6
December
-9.8
-7
-9
-9
-9
Average
-3.0
-9.4
-3.9
-2.0
-2.1
-4.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
25.7
29
45
13
25
42
February
28.4
31
28
21
35
27
March
25.4
28
37
26
21
28
April
13.0
18
9
11
13
May
7.2
8
9
10
3
June
3.0
5
3
2
6
July
2.0
1
3
3
0
August
2.1
2
2
0
0
September
3.0
2
6
3
2
October
10.2
11
9
12
7
November
14.1
17
18
9
13
December
25.1
21
38
24
27
Average
15.0
29.3
15.2
11.3
13.5
17.5
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
5.6
5
5
6
7
6
February
7.8
7
8
6
8
7
March
6.8
7
7
6
6
8
April
7.4
7
9
7
7
May
6.2
5
8
6
7
June
6.2
7
6
5
8
July
4.2
5
4
3
3
August
4.1
5
3
2
13
September
5.6
6
5
5
7
October
6.1
5
4
6
8
November
6.5
6
7
6
8
December
6.1
5
9
8
5
Average
6.2
6.5
5.9
5.9
6.0
7.1
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
240°
225°
246°
238°
229°
February
231°
230°
244°
241°
232°
March
228°
224°
242°
230°
220°
April
236°
238°
238°
234°
May
230°
232°
236°
222°
June
225°
235°
248°
225°
July
249°
246°
272°
270°
August
239°
257°
266°
253°
September
233°
243°
244°
251°
October
244°
248°
233°
244°
November
232°
228°
238°
231°
December
238°
229°
228°
239°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.