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
77.8
67
80
89
83
64
February
87.8
93
92
97
83
96
March
86.7
92
87
91
88
80
April
90.8
95
93
96
86
May
90.0
91
89
90
94
June
96.2
95
98
96
96
July
95.6
96
96
93
95
August
95.3
94
95
98
98
September
87.0
65
91
98
86
October
81.8
34
96
88
91
November
90.3
97
91
98
89
December
84.7
83
71
90
83
Average
88.5
84.1
84.3
92.2
91.9
88.7
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
0.1
-2
1
-1
1
1
February
3.8
11
6
4
-5
3
March
10.3
14
8
10
13
12
April
16.4
19
15
17
16
May
22.4
25
23
21
20
June
28.6
29
29
29
29
July
29.6
29
30
29
30
August
28.4
29
30
29
29
September
24.8
19
26
27
24
October
15.5
6
19
19
16
November
9.7
11
10
12
14
December
5.2
7
4
8
4
Average
15.2
7.7
15.7
16.7
16.7
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
-8.0
-9
-6
-12
-6
-7
February
-7.3
-2
-5
-9
-13
-6
March
0.2
2
-2
-1
3
2
April
4.6
5
3
6
4
May
11.9
12
13
11
11
June
17.3
15
17
18
18
July
18.7
18
19
19
19
August
17.6
18
18
19
17
September
13.6
9
13
15
12
October
5.9
2
5
10
5
November
-1.4
0
-1
1
2
December
-4.2
0
-5
-2
-5
Average
4.8
-3.0
5.5
5.4
6.7
6.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
9.0
12
7
5
8
13
February
8.0
3
8
10
11
3
March
6.2
4
7
8
5
4
April
5.6
6
7
4
6
May
3.8
1
5
5
3
June
3.1
2
2
4
5
July
2.0
3
3
2
3
August
2.6
4
3
1
2
September
3.8
1
5
1
8
October
4.5
3
3
10
2
November
6.2
9
12
2
5
December
6.4
8
12
3
7
Average
5.1
6.3
4.6
5.6
4.5
4.8
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
9.8
8
10
10
9
10
February
10.2
10
11
11
9
9
March
11.2
12
11
12
12
10
April
11.5
13
13
11
11
May
9.2
9
11
10
9
June
8.0
7
8
7
9
July
6.7
6
7
6
6
August
6.9
7
7
7
8
September
7.5
5
8
8
8
October
8.5
4
9
9
10
November
10.2
9
12
10
12
December
9.8
9
10
11
9
Average
9.2
10.2
8.3
9.7
8.9
9.2
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
283°
289°
277°
317°
276°
February
257°
248°
293°
323°
309°
March
290°
295°
312°
172°
239°
April
246°
238°
257°
276°
May
132°
167°
171°
004°
June
034°
204°
206°
176°
July
294°
227°
197°
168°
August
219°
220°
178°
194°
September
209°
222°
213°
216°
October
289°
252°
318°
271°
November
227°
248°
245°
224°
December
250°
212°
229°
281°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.