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
72.6
64
66
79
91
84
February
79.8
83
80
81
80
85
March
87.2
84
89
80
97
91
April
86.8
87
89
91
95
May
92.1
93
94
94
95
June
92.3
91
92
91
96
July
93.4
94
95
91
95
August
94.8
92
93
97
94
September
95.0
95
92
94
96
October
95.1
93
96
94
99
November
88.7
93
83
81
92
December
82.1
80
86
87
77
Average
87.7
77.4
88.3
88.9
91.3
92.2
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
-2.5
-1
1
-4
-1
0
February
-1.7
3
1
-2
-3
-1
March
3.4
6
3
3
7
5
April
9.5
12
9
11
8
May
17.0
17
20
16
15
June
22.0
22
22
24
23
July
24.6
25
24
23
26
August
23.7
22
25
25
24
September
20.3
21
20
20
19
October
14.1
14
15
16
12
November
6.1
6
9
7
10
December
1.6
5
2
3
2
Average
10.6
2.7
12.3
12.1
12.4
11.8
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
-8.5
-5
-4
-13
-6
-6
February
-8.4
-5
-7
-11
-10
-7
March
-4.0
-2
-4
-4
-3
-3
April
0.7
3
0
2
0
May
6.2
5
8
6
6
June
11.4
12
11
14
11
July
14.8
15
13
14
16
August
14.7
14
15
16
15
September
11.3
11
12
11
11
October
6.5
8
5
10
5
November
-1.8
0
1
0
3
December
-4.4
0
-2
-3
-3
Average
2.6
-4.2
4.4
3.2
4.3
3.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
41.5
58
42
42
17
34
February
37.9
26
45
43
36
34
March
21.6
28
24
32
9
12
April
18.0
21
18
13
12
May
11.1
11
8
8
11
June
7.7
9
6
7
2
July
6.3
8
6
10
6
August
6.9
14
8
2
7
September
7.7
6
11
10
6
October
16.8
30
17
9
11
November
25.1
24
24
24
21
December
31.9
37
22
20
31
Average
19.9
36.7
20.9
18.1
12.5
14.0
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
8.5
9
8
9
7
8
February
9.6
8
11
10
9
9
March
9.0
9
9
9
10
8
April
8.6
9
8
8
9
May
7.2
6
7
7
7
June
6.7
6
7
8
6
July
6.4
6
7
6
6
August
6.6
6
6
6
7
September
7.0
6
7
8
8
October
8.3
7
8
7
9
November
9.2
9
10
8
10
December
8.6
8
9
10
8
Average
8.0
8.6
7.4
7.9
7.7
7.9
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
222°
182°
222°
232°
229°
February
239°
237°
235°
232°
250°
March
244°
300°
243°
237°
243°
April
240°
251°
280°
277°
May
336°
203°
277°
331°
June
025°
249°
240°
256°
July
254°
249°
264°
253°
August
251°
249°
234°
264°
September
192°
250°
229°
228°
October
242°
210°
154°
227°
November
234°
216°
220°
227°
December
211°
199°
223°
246°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.