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
69.4
60
59
89
66
60
February
83.9
91
82
85
80
91
March
83.3
91
74
86
83
83
April
88.6
92
87
88
91
95
May
92.2
93
96
95
90
June
95.7
94
93
99
98
July
95.4
97
96
92
96
August
93.1
89
91
97
99
September
91.6
87
95
95
94
October
89.7
88
100
89
93
November
90.4
100
93
97
89
December
78.0
69
50
90
86
Average
87.7
83.8
85.7
90.3
90.0
89.9
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
-4.4
-3
-4
-6
-1
-4
February
-2.3
7
-3
-2
-7
-2
March
5.4
10
2
6
9
7
April
12.8
16
14
10
14
14
May
21.3
23
22
21
19
June
27.7
28
27
30
29
July
27.9
27
28
28
29
August
26.3
28
27
28
27
September
23.9
25
24
25
22
October
14.5
16
18
17
12
November
6.6
13
6
8
9
December
0.3
5
-3
2
2
Average
12.8
7.4
15.5
13.5
14.8
13.4
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
-13.8
-11
-13
-17
-9
-11
February
-12.3
-5
-12
-15
-16
-11
March
-4.5
-3
-7
-3
-1
-1
April
2.2
4
3
1
3
1
May
10.0
11
10
10
9
June
16.8
16
18
17
18
July
17.1
16
18
17
17
August
15.8
17
16
16
16
September
12.6
14
11
12
11
October
4.2
6
3
8
2
November
-3.3
2
-3
-2
-1
December
-8.2
-3
-9
-8
-8
Average
2.6
-4.3
5.0
2.8
4.2
3.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
17.8
17
26
14
16
21
February
15.0
6
17
18
15
11
March
12.6
14
23
11
11
8
April
11.6
10
17
16
4
7
May
8.3
9
5
8
10
June
4.4
7
6
2
2
July
3.4
2
4
4
2
August
3.9
7
3
2
1
September
5.4
5
5
4
9
October
9.9
12
2
10
9
November
10.3
4
21
5
5
December
14.0
11
42
6
7
Average
9.6
11.6
11.4
10.1
6.7
7.4
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
11.5
11
11
12
11
12
February
12.0
13
11
14
11
12
March
12.4
14
12
13
13
12
April
13.8
16
15
17
14
13
May
11.3
12
13
12
11
June
9.8
8
11
9
13
July
7.2
7
9
6
7
August
7.6
7
8
9
8
September
9.3
7
9
10
10
October
11.3
10
12
10
12
November
12.9
12
15
14
13
December
11.2
11
14
11
11
Average
11.0
13.3
10.0
12.0
10.5
10.9
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
297°
303°
279°
303°
286°
February
277°
277°
308°
288°
290°
March
328°
333°
333°
248°
294°
April
306°
292°
246°
310°
316°
May
131°
198°
166°
353°
June
159°
187°
250°
175°
July
284°
256°
195°
192°
August
211°
213°
175°
192°
September
196°
201°
228°
238°
October
328°
263°
192°
290°
November
227°
264°
271°
251°
December
254°
251°
262°
276°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.