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
82.2
76
61
95
78
90
February
89.3
97
85
89
90
96
March
89.8
90
79
87
93
90
April
91.4
89
87
97
94
May
96.3
96
97
97
96
June
98.2
96
99
99
99
July
98.0
99
98
96
99
August
97.2
98
95
98
100
September
95.1
95
98
97
97
October
93.5
91
99
97
92
November
91.4
100
81
100
94
December
85.1
81
78
89
89
Average
92.2
87.3
89.4
92.7
94.6
94.9
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
-4.3
-3
-3
-6
-2
-3
February
-2.7
6
-1
-4
-7
-1
March
5.8
8
3
4
10
8
April
12.5
13
9
14
14
May
21.7
24
22
22
20
June
28.3
29
29
31
28
July
29.3
29
29
30
30
August
27.4
29
27
29
28
September
24.0
26
25
25
21
October
14.3
15
17
18
11
November
5.7
9
6
7
9
December
0.2
5
-1
1
1
Average
12.4
3.8
14.8
13.6
14.8
13.7
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
-11.3
-8
-9
-16
-8
-9
February
-11.5
-4
-10
-14
-14
-10
March
-3.2
-1
-5
-3
0
0
April
2.7
4
1
4
2
May
11.1
13
11
11
11
June
17.8
19
18
20
17
July
19.4
18
20
20
20
August
17.9
19
18
19
18
September
14.3
16
14
14
12
October
6.0
8
6
9
3
November
-2.2
0
-1
-1
0
December
-7.3
-2
-7
-8
-7
Average
3.6
-5.6
5.8
4.3
5.5
4.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
14.3
12
25
9
11
21
February
13.1
7
18
18
12
6
March
12.8
15
26
15
10
12
April
15.5
18
27
12
10
May
7.1
5
6
8
9
June
4.1
3
1
2
4
July
2.5
1
2
2
3
August
3.7
4
4
3
2
September
5.5
6
4
4
5
October
9.6
10
5
4
12
November
10.3
3
26
3
9
December
14.4
11
28
14
8
Average
9.3
11.7
10.6
11.1
6.7
7.9
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
8.0
8
7
9
7
8
February
8.9
10
8
10
8
9
March
9.7
10
9
10
10
9
April
10.2
12
13
9
9
May
8.8
9
10
8
9
June
8.7
8
10
8
9
July
7.4
7
9
7
7
August
7.8
8
8
8
8
September
8.6
8
8
8
8
October
9.1
9
9
8
10
November
9.4
9
10
10
9
December
8.0
8
9
9
8
Average
8.8
9.4
8.5
9.6
8.3
8.5
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
289°
324°
282°
341°
275°
February
268°
293°
305°
279°
285°
March
328°
021°
340°
166°
263°
April
304°
258°
324°
321°
May
130°
163°
169°
026°
June
111°
235°
244°
152°
July
275°
260°
201°
210°
August
238°
189°
203°
211°
September
134°
215°
208°
253°
October
311°
250°
134°
279°
November
251°
265°
281°
241°
December
206°
122°
249°
275°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.