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
79.4
60
77
92
83
83
February
88.6
92
93
85
91
87
March
91.1
94
87
93
99
83
April
92.6
95
94
94
90
May
94.8
100
96
96
92
June
95.1
89
99
95
100
July
95.6
94
98
90
98
August
95.8
94
98
95
97
September
93.5
94
94
95
94
October
90.4
94
96
78
95
November
91.5
95
93
90
92
December
85.2
77
95
83
85
Average
90.6
83.2
91.1
94.7
91.7
92.3
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
0.5
0
4
-2
0
3
February
2.6
8
6
2
-2
2
March
7.6
11
7
9
12
9
April
12.6
15
12
15
12
May
19.9
21
22
20
19
June
25.1
25
27
27
27
July
27.1
28
28
27
30
August
26.2
26
28
29
28
September
22.9
23
24
25
23
October
16.4
17
18
19
16
November
8.6
10
11
9
13
December
3.9
8
4
7
3
Average
13.5
6.2
15.8
15.6
15.6
15.3
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
-5.5
-5
-1
-10
-3
-2
February
-4.0
-2
-3
-7
-9
-4
March
-1.6
2
0
-1
-1
1
April
4.1
4
3
4
2
May
10.6
8
12
8
9
June
16.0
14
16
16
15
July
18.3
17
17
18
18
August
17.1
15
17
18
16
September
14.2
14
13
14
11
October
8.3
8
5
11
6
November
0.9
0
2
0
3
December
-2.5
2
-1
0
-2
Average
5.7
-2.2
6.5
5.7
6.3
6.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.1
27
17
9
2
12
February
9.7
3
8
19
8
12
March
8.6
6
14
8
2
7
April
9.5
12
8
10
7
May
8.4
4
9
10
9
June
5.0
6
2
8
2
July
4.6
5
3
8
2
August
3.7
4
5
2
3
September
3.9
2
4
6
2
October
8.4
9
3
13
7
November
8.3
6
8
10
9
December
9.6
14
3
5
17
Average
8.4
11.4
7.9
6.4
7.3
6.2
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
7.7
8
7
8
7
8
February
8.6
7
10
9
8
8
March
8.9
9
9
9
10
8
April
8.4
8
9
8
8
May
7.3
7
8
7
9
June
7.0
6
7
7
7
July
6.0
5
7
6
6
August
5.5
6
6
5
6
September
6.2
5
7
7
6
October
6.9
7
8
6
7
November
7.6
8
9
7
9
December
7.3
7
8
8
7
Average
7.3
8.2
6.9
7.6
7.2
7.3
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
248°
253°
264°
258°
250°
February
244°
245°
244°
249°
274°
March
249°
271°
263°
248°
260°
April
234°
241°
257°
263°
May
126°
193°
245°
262°
June
271°
263°
229°
241°
July
253°
250°
286°
255°
August
270°
245°
233°
269°
September
217°
261°
251°
241°
October
262°
239°
249°
253°
November
242°
233°
235°
241°
December
241°
249°
235°
255°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.