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
88.6
77
83
90
92
98
February
90.4
84
92
96
89
100
March
92.2
96
83
98
98
96
April
94.9
98
88
93
97
93
May
97.3
96
99
96
94
June
99.1
98
99
100
98
July
99.0
99
99
100
100
August
98.4
98
100
98
100
September
96.2
99
94
99
94
October
94.3
92
90
93
94
November
92.3
96
78
100
97
December
90.2
87
85
95
98
Average
94.3
89.1
92.8
93.9
96.6
96.7
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
0.2
-2
0
1
4
4
February
0.4
3
3
3
-3
6
March
7.6
9
4
11
11
9
April
13.6
15
14
11
14
14
May
19.7
23
18
18
19
June
25.1
24
25
30
23
July
31.6
32
32
35
30
August
30.5
31
33
29
32
September
23.9
24
26
26
25
October
13.8
13
16
17
13
November
6.1
9
0
10
8
December
1.8
5
-2
2
4
Average
13.6
6.3
15.2
15.1
16.2
15.5
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
-9.0
-12
-7
-9
-5
-6
February
-10.7
-5
-7
-7
-11
-5
March
-4.2
-3
-6
-1
-2
-3
April
1.1
4
1
-2
1
1
May
6.6
10
6
5
6
June
11.2
12
11
13
11
July
14.1
15
15
17
13
August
13.7
14
16
13
14
September
8.8
10
11
9
9
October
1.8
2
4
4
1
November
-4.0
-2
-10
-1
-3
December
-7.0
-4
-11
-8
-5
Average
1.3
-5.9
3.1
2.3
3.0
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
6.4
16
3
8
4
1
February
9.2
20
8
4
11
0
March
6.6
4
20
2
3
5
April
6.0
3
14
7
3
2
May
4.8
4
6
8
1
June
4.5
7
4
1
11
July
0.7
1
2
0
1
August
1.1
2
1
1
0
September
3.7
5
3
0
1
October
6.5
9
10
2
9
November
5.7
1
13
0
3
December
6.8
2
15
7
3
Average
5.4
10.2
6.5
5.5
3.2
3.1
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
4.3
4
4
5
6
5
February
6.4
5
7
9
7
8
March
6.6
6
6
9
7
9
April
8.1
9
8
9
8
9
May
6.8
6
8
7
8
June
7.1
6
8
7
8
July
5.7
6
6
5
7
August
5.8
6
6
6
6
September
5.8
5
5
7
6
October
6.2
5
5
6
7
November
5.6
5
5
7
6
December
4.9
3
4
7
5
Average
6.2
5.9
5.5
6.6
6.5
7.0
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
301°
289°
279°
270°
279°
February
273°
315°
299°
282°
276°
March
298°
304°
293°
284°
278°
April
294°
288°
297°
312°
288°
May
340°
280°
295°
285°
June
308°
285°
322°
275°
July
294°
306°
344°
285°
August
288°
298°
293°
304°
September
321°
312°
283°
285°
October
294°
283°
273°
282°
November
279°
293°
272°
267°
December
265°
302°
267°
273°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.