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
88.9
88
80
89
95
87
February
87.1
87
87
83
87
85
March
91.7
86
85
93
95
96
April
94.1
88
91
99
96
May
96.9
99
93
98
100
June
99.8
99
100
100
100
July
99.8
100
99
100
100
August
99.8
100
100
100
99
September
99.0
100
100
99
95
October
94.7
91
94
97
98
November
94.7
91
91
96
98
December
90.0
89
77
89
93
Average
94.2
87.1
92.7
93.4
96.5
95.8
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
0.7
1
-1
0
1
0
February
2.4
4
1
1
2
2
March
6.9
7
3
6
7
8
April
12.4
10
12
14
13
May
18.0
18
18
18
20
June
24.5
21
25
27
24
July
27.9
28
27
28
28
August
26.7
26
26
26
29
September
23.2
22
24
24
23
October
14.4
15
14
14
17
November
8.1
8
4
10
9
December
1.5
2
-1
3
1
Average
12.7
3.5
12.8
13.6
14.5
14.3
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
-12.8
-10
-11
-13
-12
-12
February
-10.3
-8
-13
-12
-9
-11
March
-6.6
-5
-9
-7
-6
-3
April
-2.5
-4
-1
-1
-1
May
2.6
3
3
3
3
June
7.0
5
8
8
8
July
10.4
9
11
11
10
August
9.7
10
11
10
10
September
6.0
5
7
7
4
October
-2.7
-1
-2
0
-1
November
-6.5
-6
-8
-3
-5
December
-11.3
-10
-13
-9
-12
Average
-2.4
-8.0
-2.4
-2.9
-1.8
-1.2
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
17
27
13
8
15
February
16.3
17
18
19
18
16
March
12.4
19
19
12
9
7
April
8.5
14
11
3
6
May
7.3
8
10
8
3
June
3.3
8
4
3
3
July
3.0
1
6
5
3
August
3.0
2
4
4
3
September
3.6
2
5
5
3
October
8.2
14
7
5
4
November
7.8
8
12
7
6
December
13.8
13
29
18
12
Average
9.2
17.6
10.8
9.9
7.2
6.2
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
4.2
5
4
4
4
4
February
5.2
5
5
5
5
5
March
5.7
5
6
6
5
5
April
6.7
6
8
7
6
May
6.6
6
7
7
6
June
6.2
6
7
5
7
July
5.6
6
5
5
6
August
5.4
6
5
6
6
September
5.9
6
5
6
5
October
5.7
6
5
6
7
November
4.8
4
5
4
5
December
4.1
4
4
4
4
Average
5.5
5.0
5.5
5.6
5.4
5.7
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
343°
352°
338°
336°
325°
February
328°
345°
344°
340°
338°
March
327°
329°
336°
302°
325°
April
315°
295°
290°
320°
May
238°
256°
203°
303°
June
276°
287°
329°
256°
July
336°
332°
337°
318°
August
338°
337°
337°
333°
September
339°
339°
337°
337°
October
347°
342°
343°
334°
November
320°
348°
311°
320°
December
344°
353°
342°
339°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.