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
93.1
94
86
93
97
98
February
93.7
91
93
94
100
96
March
90.8
95
87
95
87
April
96.1
93
96
99
100
96
May
93.6
97
93
88
97
June
97.8
94
99
99
100
July
96.8
93
100
98
97
August
99.1
100
100
99
98
September
96.2
96
99
100
96
October
95.0
93
100
98
93
November
94.7
96
97
96
99
December
97.1
100
95
99
95
Average
94.5
93.2
94.2
97.2
97.0
95.8
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
4.0
4
-1
5
4
8
February
6.6
11
3
5
12
7
March
11.3
13
8
12
12
April
17.8
19
18
18
21
17
May
21.4
22
22
19
22
June
28.6
24
30
29
32
July
31.5
29
33
31
33
August
32.0
31
33
32
32
September
27.7
28
29
29
25
October
16.9
19
19
19
14
November
12.1
14
10
16
14
December
7.2
10
4
10
5
Average
15.9
11.5
17.0
18.8
21.0
18.6
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
-11
-8
-9
-5
-7
February
-9.9
-5
-9
-10
-6
-9
March
-4.1
-3
-5
-5
-3
April
0.0
2
0
-1
5
-2
May
6.6
8
5
7
6
June
12.6
13
12
13
12
July
15.1
15
17
13
15
August
14.6
14
16
14
15
September
9.6
10
10
11
8
October
1.0
2
3
2
-2
November
-5.9
-3
-7
-1
-4
December
-7.4
-5
-10
-8
-7
Average
0.5
-5.9
2.6
2.1
4.9
2.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.6
8
12
11
1
3
February
9.8
10
10
9
0
12
March
7.6
8
7
8
7
April
6.1
9
6
2
4
8
May
6.0
4
5
13
3
June
3.4
6
2
3
3
July
2.0
2
2
2
3
August
1.2
1
1
2
1
September
1.5
0
2
1
3
October
5.3
4
3
3
4
November
4.2
6
4
4
0
December
4.6
3
6
2
8
Average
5.5
8.7
5.0
4.1
3.6
4.3
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
9.6
7
8
11
11
12
February
10.3
9
11
11
11
11
March
10.6
9
11
12
10
April
12.2
12
10
17
8
10
May
10.2
10
10
10
11
June
8.5
7
9
8
10
July
8.1
7
9
8
10
August
8.0
7
8
8
9
September
8.0
7
8
9
8
October
9.8
8
10
10
11
November
9.6
8
10
10
8
December
10.2
10
13
11
10
Average
9.6
9.4
8.7
10.5
9.1
9.9
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
324°
318°
322°
325°
322°
February
306°
306°
318°
304°
330°
March
334°
340°
342°
320°
April
320°
323°
325°
014°
329°
May
116°
325°
116°
080°
June
116°
214°
125°
302°
July
066°
100°
118°
123°
August
005°
141°
166°
115°
September
005°
091°
346°
357°
October
348°
327°
334°
349°
November
318°
329°
313°
277°
December
321°
315°
292°
342°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.