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
69.4
64
65
89
68
72
February
86.4
92
90
79
94
93
March
90.4
86
85
89
95
93
April
88.3
85
81
85
95
May
94.0
95
94
96
96
June
96.0
95
96
98
99
July
96.3
96
96
96
98
August
93.2
91
97
91
92
September
91.3
90
92
98
94
October
87.9
87
94
83
94
November
84.3
91
77
93
85
December
74.9
63
75
70
76
Average
88.0
81.4
87.3
89.5
89.9
92.5
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
-7.1
-6
-5
-10
-4
-6
February
-6.9
2
-3
-9
-8
-4
March
2.1
3
1
1
6
4
April
8.1
8
5
10
8
May
18.3
22
18
17
18
June
24.0
25
25
25
24
July
25.6
24
25
27
27
August
23.8
24
25
25
24
September
18.9
21
20
19
18
October
9.9
11
13
13
6
November
0.6
3
2
2
3
December
-4.1
1
-4
-5
-4
Average
8.4
-1.5
11.1
9.7
10.4
9.7
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
-17.6
-13
-13
-24
-13
-15
February
-18.5
-9
-17
-24
-19
-19
March
-10.9
-8
-12
-10
-4
-8
April
-3.3
-3
-4
0
-4
May
4.8
7
5
6
4
June
11.1
12
10
14
11
July
13.1
11
12
15
14
August
12.5
12
13
16
13
September
8.5
11
7
9
6
October
2.1
3
1
6
-1
November
-7.5
-6
-6
-5
-3
December
-12.4
-5
-12
-12
-11
Average
-3.9
-11.8
-1.9
-3.8
1.0
-2.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
16.8
22
17
14
14
23
February
17.2
11
16
28
10
9
March
10.2
17
17
12
6
7
April
15.8
24
25
18
6
May
7.2
4
10
3
4
June
5.2
5
5
5
3
July
4.2
6
5
1
5
August
3.8
4
4
4
4
September
7.4
9
7
8
5
October
11.2
10
8
9
14
November
20.1
10
27
9
15
December
24.4
18
25
34
16
Average
11.5
16.2
11.0
12.7
9.1
7.2
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
4.6
4
4
5
4
4
February
5.7
6
5
6
6
6
March
5.7
6
5
6
7
6
April
5.6
5
6
5
6
May
5.3
5
6
5
6
June
4.9
3
6
5
6
July
4.1
4
4
3
4
August
4.2
3
4
6
4
September
4.6
4
4
5
6
October
5.5
5
6
4
5
November
5.6
6
5
6
6
December
4.5
5
4
6
4
Average
5.1
5.6
4.5
5.3
5.0
5.3
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°
263°
255°
243°
256°
February
272°
261°
268°
264°
260°
March
297°
289°
281°
219°
244°
April
338°
322°
304°
277°
May
151°
215°
218°
271°
June
158°
253°
255°
224°
July
277°
256°
249°
234°
August
245°
238°
225°
237°
September
162°
237°
244°
248°
October
279°
243°
203°
254°
November
263°
248°
272°
248°
December
242°
189°
251°
255°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.