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
78.0
59
82
89
85
64
February
89.5
95
91
98
85
95
March
85.7
94
86
94
86
76
April
92.2
92
98
94
95
92
May
89.3
92
88
90
88
June
95.0
99
99
97
96
July
95.7
95
92
95
96
August
94.6
91
97
97
98
September
91.7
97
93
96
84
October
88.4
95
100
93
88
November
93.4
96
97
97
93
December
88.0
82
68
95
91
Average
89.9
85.5
92.4
93.3
92.6
88.8
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
1.5
-2
2
3
3
2
February
5.1
13
7
7
-3
6
March
11.8
14
10
12
15
14
April
17.7
20
20
17
15
18
May
23.1
25
23
22
21
June
29.3
30
29
31
31
July
29.6
28
31
29
30
August
28.9
29
31
30
30
September
27.1
28
28
28
25
October
18.3
20
21
20
17
November
11.0
13
11
13
15
December
5.9
7
4
10
6
Average
16.7
11.1
18.2
18.4
17.8
17.8
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
-7.2
-9
-5
-9
-4
-6
February
-7.9
-1
-5
-8
-11
-5
March
0.6
1
-2
-1
4
3
April
5.0
7
5
4
4
5
May
12.0
13
13
12
12
June
18.0
17
18
19
20
July
19.6
19
20
19
21
August
18.2
18
19
19
19
September
14.9
15
13
15
13
October
6.8
8
6
9
5
November
-1.8
0
-1
1
2
December
-4.3
-1
-5
-2
-4
Average
5.7
-1.3
6.7
6.1
7.1
7.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
6.6
11
5
5
12
9
February
5.4
0
4
3
13
2
March
7.0
3
7
8
6
7
April
5.6
5
0
5
7
5
May
5.0
4
8
5
8
June
2.4
3
3
1
1
July
3.0
3
5
3
2
August
2.7
2
4
0
1
September
4.0
1
4
1
6
October
4.0
1
2
6
0
November
4.2
7
2
4
4
December
6.6
10
11
1
5
Average
4.7
4.6
3.7
4.7
4.5
4.1
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
9.0
8
8
9
9
10
February
10.1
10
11
12
8
10
March
11.2
12
11
12
12
10
April
11.9
13
13
14
11
11
May
9.2
8
11
9
9
June
8.1
7
8
7
10
July
6.2
6
7
6
6
August
6.3
6
6
7
7
September
8.0
8
8
8
8
October
9.2
10
9
9
9
November
10.0
9
12
9
11
December
9.3
9
10
11
9
Average
9.2
10.8
8.6
9.8
8.7
9.1
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
310°
325°
276°
325°
300°
February
272°
263°
316°
356°
316°
March
351°
342°
347°
163°
222°
April
281°
265°
245°
285°
305°
May
149°
177°
158°
021°
June
155°
190°
178°
183°
July
127°
188°
168°
155°
August
166°
154°
165°
175°
September
179°
153°
191°
224°
October
297°
259°
317°
309°
November
227°
276°
254°
240°
December
290°
237°
242°
314°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.