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
85.8
92
81
92
88
85
February
79.3
88
93
89
89
91
March
75.5
91
77
88
91
88
April
92.2
97
96
79
93
96
May
93.2
91
92
87
97
June
97.4
99
95
99
98
July
91.0
99
50
94
99
August
85.6
97
25
93
99
September
88.4
93
75
98
99
October
90.2
87
90
85
90
November
88.3
100
78
99
92
December
86.0
97
72
86
94
Average
88.2
92.1
92.8
76.2
92.0
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
-2.1
-2
-2
-1
2
-2
February
-3.0
3
0
1
-6
2
March
3.7
4
-2
7
11
7
April
11.8
16
11
7
14
11
May
19.1
22
18
19
18
June
25.3
25
23
29
25
July
27.6
28
15
33
29
August
25.4
28
8
29
31
September
22.4
24
21
26
22
October
12.3
11
14
15
10
November
4.9
8
0
9
8
December
0.3
5
-8
-1
5
Average
11.4
5.0
13.1
9.2
15.0
13.6
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
-12.1
-13
-11
-13
-8
-12
February
-13.2
-6
-11
-13
-18
-10
March
-7.3
-8
-12
-7
-5
-5
April
-2.0
0
-2
-4
-2
-4
May
5.3
8
5
4
5
June
10.9
12
10
11
11
July
12.3
13
7
14
12
August
10.8
13
3
12
12
September
7.4
9
6
8
6
October
0.1
1
3
3
-2
November
-6.0
-5
-10
-4
-5
December
-11.6
-7
-16
-13
-8
Average
-2.9
-7.0
0.6
-2.0
0.2
0.1
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
5
11
11
4
13
February
10.6
0
11
11
13
9
March
7.4
2
23
8
5
9
April
7.9
3
7
17
9
11
May
5.6
5
7
4
5
June
2.7
3
5
1
3
July
3.3
1
1
5
7
August
4.9
9
1
7
7
September
4.2
4
0
1
2
October
6.3
6
3
6
9
November
9.1
0
16
6
7
December
12.5
2
30
17
5
Average
6.4
2.4
6.6
7.6
6.2
7.1
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
11.2
11
9
14
11
11
February
10.1
11
12
14
12
11
March
10.2
11
11
14
12
10
April
12.2
15
12
14
11
12
May
10.9
9
13
11
12
June
10.2
8
11
11
10
July
8.1
9
4
9
9
August
7.8
9
3
10
9
September
9.5
9
7
9
10
October
11.9
11
11
12
12
November
11.4
10
13
12
12
December
10.6
11
9
11
11
Average
10.4
12.0
9.8
10.5
10.7
10.6
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
267°
263°
278°
268°
273°
February
269°
264°
285°
283°
265°
March
326°
133°
290°
272°
286°
April
271°
294°
317°
313°
303°
May
111°
294°
158°
158°
June
121°
253°
320°
273°
July
295°
180°
137°
233°
August
279°
264°
270°
231°
September
172°
352°
280°
281°
October
283°
296°
288°
286°
November
274°
279°
275°
257°
December
269°
298°
242°
273°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.