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
77.6
64
75
91
86
67
February
88.3
93
90
95
84
96
March
86.4
95
85
89
90
79
April
91.7
95
89
97
91
May
90.8
92
90
91
91
June
97.1
95
98
99
96
July
97.5
93
97
98
98
August
97.9
98
97
100
100
September
93.4
90
95
98
89
October
92.2
98
99
94
93
November
92.2
99
90
96
89
December
85.4
82
65
90
83
Average
90.5
84.1
91.2
92.4
94.0
89.7
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
-1.8
-2
1
-1
1
0
February
3.5
12
6
3
-5
4
March
10.5
14
9
10
13
12
April
16.7
18
15
17
16
May
23.0
25
23
21
20
June
29.2
29
29
30
29
July
30.4
30
31
30
31
August
29.1
30
30
30
30
September
26.3
28
26
28
24
October
17.1
18
18
19
15
November
9.7
12
10
12
13
December
4.8
7
3
8
4
Average
15.6
7.8
17.8
16.8
17.1
16.5
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
-9.9
-8
-6
-13
-6
-7
February
-7.1
-1
-5
-10
-12
-6
March
0.2
2
-1
-1
3
2
April
5.0
5
3
6
5
May
12.5
13
13
12
12
June
18.4
18
18
19
19
July
20.1
19
20
20
21
August
18.7
20
19
20
18
September
15.3
15
15
16
13
October
7.0
9
6
10
5
November
-1.7
1
0
1
2
December
-4.0
0
-5
-3
-6
Average
5.4
-3.4
7.3
5.8
7.1
6.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.4
20
10
9
12
22
February
13.2
2
14
13
18
7
March
13.8
9
19
12
9
14
April
10.6
10
17
4
9
May
8.3
4
9
11
13
June
3.3
2
2
3
5
July
2.5
3
4
2
3
August
3.1
5
3
1
1
September
6.4
3
6
2
12
October
7.9
6
4
8
6
November
9.0
3
16
5
9
December
12.8
14
19
7
9
Average
8.8
10.3
7.3
8.7
6.5
8.7
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
9
9
10
9
10
February
10.1
10
11
11
9
10
March
10.7
11
11
11
11
10
April
11.4
13
13
11
11
May
9.0
9
10
9
8
June
8.5
8
9
8
10
July
7.5
7
8
7
7
August
7.6
8
7
8
8
September
8.4
8
8
8
9
October
9.7
10
9
9
10
November
10.3
9
12
11
11
December
9.4
9
10
10
9
Average
9.4
9.9
9.2
9.8
9.0
9.4
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
291°
291°
286°
323°
282°
February
261°
277°
303°
319°
309°
March
324°
309°
316°
170°
252°
April
262°
247°
262°
285°
May
117°
178°
175°
004°
June
116°
198°
199°
173°
July
289°
233°
192°
174°
August
200°
228°
167°
186°
September
172°
204°
195°
211°
October
287°
258°
322°
289°
November
239°
263°
256°
231°
December
263°
202°
232°
281°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.