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
91.6
93
80
88
93
99
February
88.2
85
91
89
91
89
March
88.1
82
89
89
89
81
April
90.5
91
93
89
91
93
May
85.5
92
73
80
92
June
97.3
94
98
99
100
July
95.0
89
98
95
98
August
97.3
99
100
99
97
September
94.6
96
99
98
94
October
91.6
92
100
94
89
November
89.9
92
81
96
97
December
92.1
92
76
97
91
Average
91.3
87.1
91.9
88.4
93.3
93.4
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
3.8
3
1
4
4
5
February
3.8
7
4
3
-1
3
March
8.6
10
6
10
7
9
April
13.4
15
12
15
12
13
May
17.5
19
18
16
19
June
25.0
22
27
26
27
July
28.6
27
29
29
29
August
27.8
27
28
29
30
September
24.3
25
24
25
23
October
14.4
17
15
16
13
November
9.8
11
6
13
12
December
5.3
7
4
8
4
Average
14.3
8.3
15.0
14.9
15.7
15.9
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
-11
-7
-8
-6
-7
February
-9.4
-6
-6
-11
-12
-9
March
-5.1
-4
-6
-5
-6
-4
April
-2.4
0
0
-3
-3
-4
May
4.0
6
4
4
4
June
9.1
10
9
11
9
July
11.3
12
14
13
10
August
11.3
12
17
12
9
September
7.7
7
14
8
6
October
-1.6
-1
3
1
-1
November
-5.3
-5
-8
-2
-4
December
-7.3
-5
-6
-5
-8
Average
0.0
-6.6
1.5
1.0
1.5
0.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.0
10
17
19
3
4
February
16.4
17
10
13
21
20
March
10.8
18
11
5
11
15
April
11.1
13
12
5
16
13
May
9.8
3
6
12
6
June
4.3
10
3
1
4
July
4.1
6
6
3
2
August
2.2
6
3
0
2
September
4.3
5
5
1
5
October
8.5
9
1
5
11
November
8.7
15
10
4
3
December
9.1
5
8
5
15
Average
8.7
14.4
8.4
7.2
6.8
7.6
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
11.6
10
8
11
14
15
February
13.0
12
14
12
13
13
March
11.5
10
12
12
11
12
April
12.2
13
10
16
11
10
May
9.5
8
12
9
10
June
9.1
8
10
8
10
July
7.5
7
7
7
9
August
8.4
8
9
9
9
September
9.3
9
8
10
10
October
11.0
9
10
10
13
November
11.5
10
7
13
13
December
12.7
13
11
15
10
Average
10.6
11.1
9.4
10.9
10.4
10.9
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
292°
273°
298°
296°
284°
February
280°
282°
287°
271°
284°
March
258°
263°
320°
287°
273°
April
300°
274°
287°
321°
295°
May
200°
274°
189°
241°
June
163°
252°
315°
265°
July
290°
281°
105°
251°
August
271°
295°
255°
256°
September
281°
274°
282°
283°
October
300°
268°
289°
274°
November
280°
285°
285°
264°
December
293°
280°
272°
298°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.