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
88.0
88
86
91
93
85
February
90.1
89
94
80
92
96
March
91.5
90
88
82
96
92
April
88.6
82
78
87
94
May
93.3
94
90
94
95
June
94.3
94
95
91
98
July
97.6
97
95
99
99
August
91.8
91
91
89
90
September
90.8
90
86
97
95
October
92.5
91
97
83
97
November
94.1
95
93
98
99
December
85.4
83
81
78
94
Average
91.5
89.1
90.5
88.5
91.5
94.4
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
-7.7
-5
-5
-10
-4
-4
February
-6.9
0
-5
-8
-7
-3
March
1.8
3
0
0
5
3
April
7.4
6
4
10
8
May
16.4
18
16
17
17
June
22.6
23
23
25
23
July
25.8
24
25
27
27
August
23.8
23
25
26
24
September
19.0
21
19
21
18
October
10.8
11
13
14
7
November
2.2
4
3
4
6
December
-4.9
3
-3
-3
-3
Average
8.4
-1.3
10.3
9.4
11.2
10.1
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
-16.1
-13
-13
-23
-14
-13
February
-18.8
-11
-16
-23
-20
-17
March
-10.3
-7
-11
-11
-8
-8
April
-4.7
-3
-3
-1
-4
May
2.8
4
4
3
3
June
9.1
10
9
11
9
July
12.0
11
11
12
13
August
11.6
11
13
13
12
September
8.1
10
7
8
6
October
1.9
3
2
6
-1
November
-6.2
-5
-4
-4
-4
December
-12.3
-5
-11
-14
-12
Average
-3.4
-11.6
-1.7
-2.0
-1.5
-2.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
30.9
32
27
42
12
39
February
24.8
15
24
40
24
21
March
15.2
21
20
30
5
14
April
18.4
31
31
19
6
May
10.6
11
12
9
7
June
8.5
6
12
8
8
July
6.3
8
11
1
6
August
7.0
9
6
5
7
September
9.3
6
13
7
8
October
14.8
16
11
6
14
November
22.6
12
39
9
14
December
29.0
22
44
41
24
Average
16.2
22.4
15.5
22.1
11.0
12.8
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
6.9
7
7
8
7
7
February
7.9
7
8
8
8
8
March
8.6
9
8
9
9
8
April
8.9
9
10
8
9
May
8.1
9
9
8
8
June
7.3
7
8
7
8
July
6.6
6
7
7
6
August
6.8
6
7
8
7
September
7.1
7
7
8
8
October
7.5
7
7
7
8
November
7.7
7
8
9
8
December
7.1
6
8
8
7
Average
7.6
7.7
7.2
8.0
7.6
7.7
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
287°
290°
282°
290°
289°
February
320°
292°
288°
274°
289°
March
310°
056°
332°
310°
340°
April
044°
062°
047°
331°
May
066°
080°
079°
042°
June
070°
294°
175°
044°
July
254°
271°
180°
242°
August
268°
253°
222°
142°
September
097°
342°
240°
272°
October
321°
291°
009°
267°
November
273°
342°
296°
275°
December
317°
086°
296°
280°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.