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
82.5
71
84
87
88
87
February
86.1
88
89
92
82
89
March
88.5
89
85
82
97
91
April
92.1
96
92
94
98
May
93.0
97
92
98
95
June
94.0
89
94
94
98
July
96.2
91
97
97
99
August
95.9
96
96
95
95
September
95.7
98
96
98
96
October
93.6
94
99
90
94
November
92.3
92
89
93
96
December
81.9
69
81
88
83
Average
90.6
83.0
90.3
91.9
93.4
93.8
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
-2.5
-1
1
-4
-1
0
February
0.3
3
2
-1
-2
0
March
3.8
7
3
4
6
6
April
10.5
13
11
12
9
May
17.3
17
20
17
17
June
22.3
23
22
24
23
July
25.6
26
25
24
28
August
24.8
24
26
26
25
September
21.3
23
20
22
20
October
14.8
16
15
17
14
November
6.9
7
9
7
10
December
1.5
4
2
3
2
Average
11.2
2.9
13.0
12.7
12.9
12.7
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
-9.5
-6
-5
-15
-7
-6
February
-8.6
-4
-7
-10
-9
-7
March
-4.6
-1
-3
-4
-3
-1
April
2.2
4
2
3
1
May
7.9
7
10
8
7
June
13.8
15
14
15
13
July
17.6
18
17
16
20
August
17.0
16
18
19
17
September
12.7
13
13
13
12
October
7.4
9
6
10
6
November
0.0
0
2
0
3
December
-5.5
-1
-2
-3
-3
Average
3.6
-4.5
5.4
4.4
5.3
5.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
30.0
38
32
37
16
23
February
25.9
11
26
37
32
31
March
20.3
19
25
29
7
20
April
17.8
14
16
18
16
May
11.6
10
10
5
9
June
8.6
11
10
7
3
July
4.9
5
8
6
4
August
5.0
7
8
2
6
September
6.2
1
12
9
3
October
13.7
16
14
12
13
November
16.6
14
14
11
13
December
27.9
33
27
18
26
Average
15.6
22.6
15.0
16.9
10.9
12.8
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
9.0
9
8
10
8
8
February
10.1
9
11
12
9
10
March
9.4
9
10
9
9
9
April
9.6
9
10
9
11
May
8.0
8
7
8
8
June
8.1
7
9
8
8
July
8.0
8
9
7
8
August
8.2
8
8
8
8
September
8.1
7
8
9
10
October
9.6
9
10
9
10
November
10.1
10
10
9
11
December
9.4
8
10
10
11
Average
8.9
9.2
8.5
9.0
8.5
9.2
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
289°
340°
287°
321°
278°
February
223°
224°
235°
243°
250°
March
230°
280°
241°
242°
208°
April
201°
230°
260°
248°
May
203°
166°
201°
232°
June
096°
208°
204°
199°
July
206°
214°
177°
206°
August
209°
197°
190°
213°
September
175°
269°
209°
205°
October
237°
196°
132°
235°
November
232°
225°
238°
219°
December
347°
246°
225°
239°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.