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
79.0
75
61
96
73
86
February
86.9
91
92
96
69
96
March
89.8
97
84
88
96
82
April
89.9
89
90
94
91
May
90.8
96
94
80
93
June
94.5
91
93
91
97
July
97.2
99
95
95
99
August
93.7
95
90
90
97
September
90.8
90
87
97
95
October
92.0
91
97
86
96
November
92.4
96
88
96
92
December
83.9
88
83
82
98
Average
90.2
88.4
90.0
91.5
88.5
93.5
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
-2.5
-1
0
-4
-1
1
February
1.8
8
3
-1
-1
1
March
6.7
10
5
5
11
7
April
13.3
15
11
16
13
May
21.6
23
22
21
20
June
27.1
28
27
29
28
July
29.0
29
28
28
30
August
27.3
28
27
29
29
September
23.4
24
23
25
21
October
15.2
16
16
18
12
November
7.2
9
9
8
12
December
1.7
5
1
2
2
Average
13.3
5.6
15.4
14.2
15.8
14.6
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
-9.7
-6
-5
-14
-7
-6
February
-9.6
-4
-7
-11
-10
-10
March
-3.2
-2
-3
-3
0
0
April
2.2
3
2
4
2
May
9.3
9
11
9
9
June
14.7
14
14
16
14
July
17.0
16
16
16
19
August
15.8
16
16
17
16
September
12.0
14
12
11
11
October
5.5
7
4
9
3
November
-2.5
-1
-1
-2
1
December
-6.7
-1
-4
-6
-5
Average
3.2
-4.1
5.0
3.8
5.2
4.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
9.8
12
15
6
5
8
February
7.1
1
13
8
5
6
March
8.3
7
11
12
4
13
April
8.3
8
8
5
5
May
5.8
7
0
6
8
June
6.6
6
7
7
7
July
3.3
2
3
5
3
August
3.9
3
4
5
3
September
6.2
7
8
3
9
October
7.0
9
5
3
7
November
8.1
3
16
6
9
December
9.6
5
21
9
3
Average
6.8
6.3
7.0
7.2
5.1
6.6
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
5.6
6
5
7
5
6
February
6.7
7
7
8
7
7
March
7.3
8
6
7
8
7
April
6.6
8
10
7
0
May
6.1
5
7
6
6
June
5.8
5
7
6
6
July
4.7
5
5
4
5
August
4.9
5
5
5
5
September
5.5
5
5
5
6
October
6.5
6
6
5
7
November
6.9
6
7
7
8
December
6.0
5
6
6
6
Average
6.1
6.8
5.7
6.6
5.9
5.5
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
268°
274°
257°
293°
266°
February
241°
259°
270°
250°
272°
March
284°
319°
300°
221°
242°
April
241°
222°
275°
360°
May
037°
161°
226°
019°
June
024°
246°
233°
179°
July
267°
257°
287°
254°
August
295°
249°
207°
230°
September
119°
260°
260°
237°
October
283°
242°
349°
262°
November
250°
239°
244°
236°
December
261°
177°
256°
263°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.