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
78.2
57
70
97
75
69
February
88.0
85
89
94
83
94
March
87.8
91
83
93
89
81
April
92.7
94
95
95
95
May
93.7
90
97
96
92
June
97.3
98
98
99
100
July
96.8
90
98
95
99
August
95.4
95
93
94
98
September
95.1
90
99
99
96
October
90.2
92
100
92
90
November
92.7
98
89
95
91
December
85.9
75
77
98
88
Average
90.1
77.4
88.9
94.8
92.8
91.6
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
-1.7
-4
-1
3
1
0
February
2.0
10
3
5
-6
3
March
9.5
12
6
11
13
11
April
16.2
18
16
18
17
May
22.6
26
23
22
20
June
29.8
30
30
31
31
July
30.2
30
32
30
31
August
28.8
31
30
30
30
September
26.2
28
28
27
24
October
16.5
17
20
19
14
November
9.5
12
9
12
12
December
3.3
6
1
7
4
Average
15.0
6.0
17.0
17.8
17.0
16.4
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
-10.5
-11
-10
-12
-6
-8
February
-10.7
-4
-8
-11
-15
-8
March
-2.1
-2
-4
-3
0
0
April
2.4
3
2
3
2
May
10.4
12
11
10
10
June
16.4
15
17
17
18
July
18.0
17
19
18
19
August
16.4
18
17
16
17
September
13.0
13
12
13
11
October
4.0
6
3
6
2
November
-3.2
-2
-4
-1
-2
December
-7.1
-4
-8
-6
-8
Average
3.0
-6.6
4.6
3.8
4.7
4.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.6
20
16
2
10
13
February
7.8
3
13
7
10
3
March
9.8
10
13
8
10
11
April
7.1
7
7
5
5
May
6.3
3
4
5
12
June
3.5
4
5
2
1
July
2.9
6
4
3
2
August
3.0
4
6
1
0
September
3.7
9
1
2
5
October
6.7
6
2
7
6
November
5.6
3
12
3
7
December
8.1
8
16
2
7
Average
6.6
10.8
7.3
5.7
4.7
5.7
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
9.9
9
9
10
10
10
February
10.3
10
10
13
9
10
March
11.6
12
12
13
12
11
April
12.3
14
15
12
11
May
9.5
9
11
10
10
June
8.8
7
9
8
11
July
7.5
7
8
8
8
August
7.7
8
8
9
9
September
8.9
8
9
9
10
October
10.1
10
11
9
10
November
10.4
10
13
10
10
December
9.9
9
11
11
10
Average
9.8
10.6
9.3
10.8
9.5
9.9
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
321°
330°
304°
330°
318°
February
292°
331°
322°
323°
334°
March
348°
332°
343°
146°
228°
April
297°
290°
314°
318°
May
132°
185°
142°
351°
June
124°
208°
190°
166°
July
033°
201°
161°
167°
August
194°
163°
147°
169°
September
169°
157°
173°
270°
October
307°
282°
250°
310°
November
246°
303°
288°
259°
December
302°
299°
320°
316°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.