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
79.3
76
74
93
69
84
February
89.6
98
92
96
89
97
March
90.9
93
87
90
94
87
April
90.5
90
87
90
96
91
May
91.9
95
92
91
94
June
93.9
96
93
93
95
July
93.0
93
92
89
95
August
91.8
96
88
91
98
September
91.8
89
94
94
94
October
92.2
91
97
93
94
November
90.3
95
84
98
89
December
85.7
85
81
84
97
Average
90.3
89.3
90.5
91.1
90.5
93.0
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
-3.7
-2
-1
-5
-1
-1
February
0.5
9
2
-2
-5
1
March
7.0
10
5
5
11
8
April
13.3
15
14
11
15
13
May
21.7
24
22
21
21
June
27.3
28
27
30
28
July
28.5
28
28
28
29
August
27.0
28
27
27
28
September
23.4
25
23
24
21
October
14.7
15
16
18
11
November
6.3
9
8
8
10
December
1.0
5
0
2
1
Average
13.2
7.7
15.1
13.8
14.9
14.0
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
-13.7
-9
-9
-20
-10
-10
February
-14.9
-7
-11
-16
-19
-15
March
-6.5
-4
-6
-5
-3
-2
April
-1.4
1
0
-1
1
-2
May
6.3
5
8
5
6
June
11.6
11
10
13
12
July
13.6
12
14
13
15
August
12.2
13
13
13
13
September
9.1
11
8
8
7
October
2.3
4
0
6
-1
November
-5.5
-5
-4
-5
-2
December
-9.3
-5
-8
-9
-10
Average
0.1
-5.2
1.8
0.4
1.2
1.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.2
12
16
10
6
17
February
9.1
1
12
8
9
6
March
8.9
10
12
10
8
13
April
11.6
16
13
17
5
8
May
8.7
7
8
10
9
June
5.6
4
8
3
7
July
2.9
3
3
4
2
August
3.8
1
7
5
1
September
5.2
4
3
3
9
October
8.7
9
6
4
8
November
8.9
2
22
5
8
December
10.5
7
14
9
4
Average
8.0
10.1
7.2
9.1
5.7
7.5
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
4.5
4
4
5
4
4
February
5.5
6
5
6
5
6
March
6.0
6
5
6
6
5
April
6.2
7
7
7
6
6
May
5.1
4
5
5
6
June
4.6
4
5
5
5
July
3.8
4
4
3
4
August
3.9
4
3
3
4
September
4.1
4
4
4
4
October
5.0
5
4
4
6
November
5.1
5
5
5
5
December
4.1
3
4
4
4
Average
4.9
5.6
4.5
5.0
4.5
4.9
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
280°
293°
274°
318°
283°
February
267°
287°
284°
277°
279°
March
308°
327°
317°
246°
277°
April
280°
255°
252°
283°
305°
May
010°
206°
251°
348°
June
027°
261°
256°
211°
July
280°
272°
267°
248°
August
291°
276°
239°
263°
September
148°
269°
266°
261°
October
299°
265°
327°
282°
November
262°
258°
271°
252°
December
283°
166°
267°
268°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.