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
74.8
62
73
86
72
77
February
83.2
89
89
85
93
85
March
86.8
87
86
85
98
87
April
90.9
96
93
97
86
May
92.4
99
92
97
99
June
94.1
90
98
92
97
July
95.2
94
97
89
96
August
93.2
91
95
92
92
September
91.8
88
94
97
100
October
86.6
95
96
75
85
November
89.2
93
87
91
93
December
80.1
69
93
86
94
Average
87.8
80.3
89.2
92.0
88.3
91.1
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
-1.5
-1
2
-3
-1
2
February
1.7
7
4
0
-4
0
March
7.0
10
6
7
9
8
April
13.0
16
12
13
12
May
20.4
22
22
18
19
June
25.7
27
27
26
26
July
27.7
27
28
25
30
August
26.4
26
27
26
27
September
23.4
23
22
23
24
October
15.7
16
17
18
9
November
7.5
9
10
7
12
December
2.8
6
3
5
2
Average
13.1
5.6
15.3
14.7
13.9
12.8
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
-6.4
-4
-2
-11
-5
-2
February
-6.8
-2
-4
-8
-9
-6
March
-2.7
1
-2
-2
1
0
April
3.9
4
3
6
2
May
10.1
8
11
10
8
June
15.5
14
15
18
14
July
17.6
17
17
19
18
August
16.2
16
17
18
16
September
13.1
13
13
12
16
October
7.1
8
5
10
4
November
0.2
0
1
0
3
December
-3.8
1
-2
-2
-1
Average
4.8
-2.0
6.0
5.1
6.7
4.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
20.9
36
21
16
28
13
February
15.5
2
11
16
10
21
March
11.1
12
14
13
0
7
April
11.0
11
12
10
12
May
7.2
5
8
3
4
June
4.8
6
4
8
1
July
3.4
5
2
7
3
August
5.7
6
8
0
5
September
5.0
6
7
5
0
October
13.0
15
7
15
11
November
12.3
10
15
12
10
December
13.0
15
7
10
11
Average
10.4
15.7
9.8
9.3
9.6
7.7
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
8.1
8
7
9
6
8
February
9.2
8
11
10
7
9
March
9.2
10
9
9
10
9
April
9.3
9
10
9
8
May
7.8
6
8
8
8
June
7.1
6
8
8
6
July
6.0
5
7
6
6
August
5.8
7
6
4
6
September
6.1
5
5
7
8
October
7.7
7
8
7
8
November
8.6
8
9
8
10
December
8.1
7
9
9
8
Average
7.8
8.6
7.1
8.0
7.5
7.9
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
246°
241°
241°
293°
236°
February
243°
245°
230°
261°
283°
March
239°
270°
259°
248°
235°
April
239°
226°
235°
270°
May
013°
175°
260°
290°
June
007°
252°
246°
241°
July
256°
255°
265°
255°
August
267°
236°
213°
246°
September
165°
254°
251°
237°
October
246°
229°
220°
259°
November
242°
222°
231°
233°
December
259°
204°
231°
255°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.