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
72.2
60
54
94
78
70
February
85.6
94
90
94
79
93
March
85.8
95
85
87
88
75
April
91.5
93
92
90
96
93
May
86.8
93
92
87
84
June
94.2
94
96
96
94
July
95.6
96
95
93
98
August
94.7
95
93
97
99
September
91.2
93
96
93
87
October
88.7
87
100
89
92
November
88.8
98
85
96
87
December
78.0
72
62
87
85
Average
88.2
86.2
88.3
91.4
90.3
88.8
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
-3.5
-3
-2
-3
-1
-2
February
-1.6
9
1
-1
-7
0
March
7.7
10
6
8
11
9
April
14.9
15
16
12
16
15
May
21.9
25
23
21
20
June
25.6
28
28
17
28
July
28.4
28
29
29
29
August
27.4
28
28
29
28
September
24.4
26
24
26
22
October
15.3
17
17
18
13
November
7.5
11
8
9
11
December
2.9
6
1
5
2
Average
14.1
7.6
15.8
14.9
14.4
14.7
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
-11.8
-9
-8
-15
-8
-10
February
-10.1
-3
-8
-12
-15
-9
March
-2.1
-2
-3
-1
1
0
April
2.7
3
3
1
4
1
May
10.0
10
11
9
9
June
14.2
14
15
8
17
July
15.7
13
15
16
17
August
15.2
15
14
16
15
September
12.3
13
11
12
11
October
4.4
6
4
8
2
November
-3.9
-1
-2
-1
0
December
-6.5
-3
-6
-5
-8
Average
3.4
-3.1
4.4
3.4
3.8
3.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
11.8
12
16
4
5
23
February
8.7
0
8
7
11
6
March
9.8
10
12
11
8
8
April
8.7
13
6
11
3
7
May
7.7
4
7
9
11
June
5.1
4
7
3
4
July
3.1
3
3
3
2
August
4.2
4
4
3
2
September
6.1
4
3
4
11
October
8.7
7
3
9
8
November
7.4
2
14
2
5
December
8.6
8
21
3
6
Average
7.5
8.9
6.2
7.2
5.1
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
9.3
9
9
11
8
10
February
10.4
11
10
12
9
10
March
10.6
12
11
11
11
10
April
12.7
14
14
14
11
11
May
9.4
10
11
10
8
June
8.2
6
9
8
10
July
6.4
6
7
6
6
August
6.3
6
6
6
7
September
7.8
7
8
8
9
October
9.6
11
9
9
11
November
10.6
9
12
12
11
December
9.1
9
10
10
9
Average
9.3
11.7
8.8
9.9
8.8
9.1
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
292°
300°
288°
324°
260°
February
271°
280°
301°
309°
294°
March
322°
307°
319°
159°
281°
April
302°
266°
250°
286°
300°
May
129°
190°
185°
021°
June
143°
223°
235°
174°
July
277°
238°
240°
214°
August
222°
218°
174°
213°
September
191°
240°
234°
251°
October
290°
261°
343°
285°
November
248°
257°
268°
244°
December
273°
195°
249°
280°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.