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
85.4
80
77
94
92
94
February
88.7
81
84
89
90
96
March
91.1
90
84
92
93
89
April
93.8
99
81
93
95
98
May
95.9
97
91
99
100
June
99.1
98
99
99
99
July
99.7
98
100
100
100
August
98.8
100
100
98
99
September
98.8
98
100
100
98
October
96.2
95
94
96
99
November
93.6
91
91
97
97
December
90.4
89
84
94
98
Average
93.9
87.9
91.1
94.4
96.2
97.5
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
-2.6
-1
-5
1
1
-1
February
-1.8
2
-3
1
-1
-1
March
5.5
5
0
7
6
6
April
11.8
13
8
12
12
12
May
17.9
19
17
19
20
June
24.6
22
25
28
24
July
30.1
30
31
31
29
August
28.2
27
29
27
31
September
22.8
23
25
24
22
October
13.2
15
15
13
15
November
5.9
7
1
9
6
December
-1.8
1
-4
3
0
Average
12.2
4.9
12.1
13.9
14.3
13.9
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
-10.4
-9
-11
-9
-9
-9
February
-10.6
-6
-12
-10
-10
-11
March
-5.4
-4
-9
-5
-5
-3
April
-2.8
0
-3
-2
-3
-2
May
3.8
6
3
4
4
June
9.2
9
9
12
9
July
13.9
13
15
15
13
August
12.2
13
14
12
13
September
7.8
8
9
8
7
October
0.3
2
2
2
1
November
-5.7
-3
-8
-2
-5
December
-9.0
-8
-12
-7
-10
Average
0.1
-5.1
0.4
0.8
1.5
0.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.5
14
20
3
5
8
February
10.7
17
18
11
9
5
March
10.2
14
18
12
7
12
April
8.2
4
17
8
7
3
May
5.7
6
11
1
2
June
3.4
7
3
3
4
July
1.6
1
3
2
1
August
1.6
3
2
2
1
September
2.7
6
3
2
1
October
4.4
9
1
5
3
November
7.1
10
12
2
3
December
7.7
8
19
8
2
Average
6.5
11.8
10.0
6.6
4.1
3.4
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
11.0
9
12
14
11
13
February
13.1
11
13
15
17
13
March
11.6
12
11
12
12
13
April
12.8
14
12
14
13
12
May
10.8
9
13
11
12
June
10.1
9
11
9
12
July
8.1
9
9
7
9
August
8.3
9
7
9
8
September
9.3
9
8
8
11
October
11.7
10
10
11
15
November
11.6
9
13
12
11
December
10.6
8
10
13
10
Average
10.8
11.4
9.9
11.2
10.9
11.4
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
253°
265°
256°
248°
253°
February
247°
258°
262°
265°
266°
March
238°
245°
262°
256°
262°
April
250°
274°
260°
297°
271°
May
317°
252°
260°
245°
June
224°
247°
257°
246°
July
256°
240°
270°
260°
August
239°
258°
255°
258°
September
242°
253°
256°
275°
October
246°
266°
238°
264°
November
249°
245°
260°
239°
December
253°
244°
241°
256°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.