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
72.0
58
64
88
77
73
February
81.6
89
84
86
81
89
March
89.0
90
88
86
95
82
April
89.8
90
91
97
92
May
91.1
94
87
97
89
June
92.4
84
95
95
99
July
95.9
92
95
96
98
August
94.8
94
93
98
98
September
91.2
89
90
98
85
October
88.7
91
90
89
92
November
88.3
93
87
97
87
December
83.8
72
73
89
97
Average
87.8
79.1
86.8
89.1
92.8
90.5
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
-1.7
-2
3
-3
0
2
February
3.1
10
5
1
-4
2
March
9.1
12
8
10
12
10
April
15.1
17
13
17
15
May
21.8
23
23
21
20
June
27.7
28
28
29
29
July
28.8
28
29
28
30
August
27.9
27
28
29
29
September
25.0
24
24
27
23
October
16.9
17
18
19
16
November
8.3
10
11
9
12
December
4.3
6
4
7
4
Average
14.5
6.5
16.4
15.9
16.1
15.8
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
-7.0
-6
-3
-12
-5
-4
February
-7.7
-2
-4
-8
-12
-6
March
-1.4
1
-1
0
1
0
April
3.7
4
4
5
3
May
10.3
10
12
10
10
June
16.0
14
16
17
17
July
18.5
18
19
18
20
August
16.9
16
18
19
17
September
14.1
15
14
14
13
October
6.9
8
5
11
4
November
-1.5
-1
1
-1
3
December
-4.5
1
-3
-2
-4
Average
4.7
-3.5
6.3
5.5
6.2
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
15.2
21
25
14
12
10
February
10.2
0
18
12
15
10
March
9.3
9
12
18
5
12
April
11.4
12
14
7
11
May
7.8
7
10
6
11
June
5.0
4
6
6
5
July
3.8
7
5
3
4
August
3.0
3
7
1
1
September
5.9
9
6
4
9
October
10.5
14
7
15
8
November
8.8
7
15
4
4
December
8.7
17
16
5
5
Average
8.2
9.9
10.8
10.2
6.5
7.3
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
9.4
9
8
11
9
9
February
10.1
10
11
11
9
11
March
10.5
11
10
10
11
10
April
10.5
11
12
10
10
May
8.9
8
10
9
9
June
8.0
8
8
8
8
July
7.1
6
8
7
7
August
7.0
7
8
6
7
September
7.6
7
8
8
9
October
9.1
9
9
8
10
November
9.6
9
11
10
10
December
9.2
9
9
10
9
Average
9.0
10.0
8.5
9.4
8.7
8.8
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
266°
260°
270°
285°
253°
February
251°
254°
247°
287°
295°
March
261°
277°
265°
204°
231°
April
237°
221°
247°
283°
May
052°
143°
185°
005°
June
034°
237°
219°
182°
July
268°
255°
296°
237°
August
307°
253°
181°
246°
September
139°
296°
240°
241°
October
265°
241°
337°
265°
November
239°
226°
240°
221°
December
241°
195°
228°
256°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.