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
89.9
87
90
92
88
98
February
84.8
82
93
90
79
91
March
86.8
83
77
90
96
86
April
89.6
90
88
93
89
May
93.1
94
98
97
92
June
81.2
97
99
9
100
July
75.3
99
97
0
August
75.0
96
97
6
100
September
91.7
87
96
99
October
87.2
81
87
93
79
November
90.1
96
83
99
91
December
89.4
95
87
90
84
Average
86.6
83.8
91.3
92.8
68.5
89.5
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
2.8
0
3
4
5
4
February
-2.4
3
3
3
-8
4
March
4.9
5
1
8
10
5
April
10.6
12
9
12
10
May
17.0
21
17
16
17
June
22.7
22
23
27
20
July
29.0
29
29
32
August
28.1
29
31
26
29
September
23.2
23
26
24
October
10.9
12
16
13
2
November
6.5
9
1
11
8
December
2.5
9
-5
-1
4
Average
9.6
2.4
14.3
13.8
13.8
8.5
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
-6.1
-11
-5
-7
-2
-3
February
-10.1
-5
-6
-9
-14
-6
March
-5.4
-5
-7
-3
-1
-4
April
0.2
1
-2
1
-1
May
5.4
8
5
5
5
June
10.3
10
9
13
10
July
14.0
13
15
16
August
12.6
13
13
12
28
September
10.1
11
11
11
October
1.1
2
7
2
-6
November
-3.5
0
-7
0
-1
December
-7.6
-1
-14
-12
-3
Average
-1.5
-7.2
3.2
1.6
2.4
-1.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.4
20
15
11
16
11
February
25.8
23
12
17
41
16
March
16.2
20
23
19
7
18
April
19.0
19
21
23
17
May
8.0
3
7
9
6
June
5.3
6
6
0
12
July
1.3
0
2
0
August
3.3
5
3
0
0
September
7.1
8
5
2
October
13.8
18
6
5
28
November
12.7
3
19
4
10
December
14.4
4
30
20
8
Average
13.4
21.0
9.5
11.5
9.7
13.4
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
9.9
9
9
11
12
11
February
10.1
9
11
12
11
10
March
9.6
9
10
11
9
11
April
10.1
9
11
10
11
May
8.9
8
10
9
9
June
8.0
7
10
8
8
July
7.1
7
7
7
August
8.4
8
8
9
10
September
8.4
8
8
9
October
9.2
8
7
11
9
November
10.2
9
11
12
12
December
9.2
8
8
10
8
Average
9.3
8.6
8.3
9.7
9.5
10.0
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
237°
242°
253°
257°
261°
February
237°
228°
266°
258°
263°
March
131°
096°
277°
262°
271°
April
269°
281°
282°
287°
May
090°
271°
293°
283°
June
208°
259°
285°
273°
July
291°
302°
028°
August
271°
268°
278°
330°
September
275°
298°
269°
October
283°
282°
254°
248°
November
259°
254°
260°
254°
December
251°
244°
246°
259°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.