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
75.9
63
67
81
83
83
February
84.2
86
86
85
86
82
March
87.3
88
79
92
93
82
April
91.6
93
95
89
96
91
May
94.0
98
91
95
94
June
94.5
85
98
98
99
July
96.8
92
96
96
100
August
94.5
91
94
96
94
September
93.3
90
92
93
94
October
90.4
90
96
86
88
November
90.8
93
87
94
92
December
84.7
81
81
78
92
Average
89.7
83.3
87.4
90.9
92.0
91.4
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
2
5
0
2
5
February
5.7
9
9
3
-1
4
March
10.5
13
9
13
15
11
April
16.8
18
18
15
18
15
May
22.7
23
24
22
21
June
27.9
27
29
28
29
July
29.6
29
30
29
32
August
28.4
28
28
30
29
September
25.5
25
25
26
24
October
19.1
19
19
21
17
November
10.4
12
13
10
14
December
6.1
9
5
9
5
Average
16.3
10.5
17.8
17.4
17.4
17.3
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
-5.9
-4
0
-9
-2
-1
February
-4.9
-1
-2
-5
-8
-3
March
0.7
3
0
2
2
3
April
5.7
8
6
5
6
4
May
12.1
11
14
11
11
June
17.2
15
18
19
18
July
19.3
19
20
19
21
August
17.7
16
18
19
17
September
15.3
15
15
16
14
October
8.9
9
7
12
8
November
1.5
2
3
1
4
December
-2.9
3
-1
1
-2
Average
6.8
1.5
7.7
7.4
7.9
7.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
17.3
25
19
18
10
14
February
13.3
9
10
19
16
16
March
11.3
9
19
11
5
11
April
11.2
12
10
15
8
9
May
8.0
5
10
7
10
June
5.6
8
3
5
1
July
4.2
4
9
3
2
August
3.5
5
4
2
2
September
4.5
3
3
6
3
October
9.4
12
5
12
7
November
9.6
13
12
6
11
December
9.9
14
1
6
12
Average
9.1
13.2
9.7
9.1
6.9
7.6
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
10.4
10
10
11
9
10
February
11.0
10
12
12
11
11
March
11.4
12
12
12
12
10
April
10.9
11
11
11
10
11
May
9.6
9
10
9
10
June
8.6
8
8
9
9
July
7.1
6
8
7
7
August
7.0
7
7
6
7
September
7.7
7
8
10
8
October
9.4
9
11
9
9
November
10.3
10
11
11
11
December
9.6
9
9
10
10
Average
9.5
10.8
9.1
9.7
9.1
9.3
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
233°
239°
258°
258°
229°
February
239°
232°
230°
271°
259°
March
232°
256°
244°
229°
252°
April
249°
235°
230°
240°
258°
May
039°
174°
277°
244°
June
351°
253°
224°
263°
July
252°
243°
263°
238°
August
253°
220°
216°
274°
September
073°
261°
245°
218°
October
253°
234°
233°
232°
November
234°
225°
230°
233°
December
230°
227°
211°
239°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.