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
77.5
68
78
89
80
76
February
85.0
92
92
87
89
75
March
88.9
92
84
95
93
82
April
91.8
93
95
92
96
91
May
95.1
98
93
94
95
June
94.2
88
98
97
97
July
95.7
95
95
96
97
August
94.4
93
93
96
96
September
90.2
87
91
93
93
October
90.7
91
98
86
85
November
89.0
94
93
93
90
December
82.0
80
82
84
89
Average
88.5
87.0
90.1
92.7
92.0
90.7
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
2.2
1
4
0
1
4
February
4.6
9
9
4
-1
2
March
10.0
12
9
12
14
11
April
15.2
17
17
14
16
14
May
22.1
22
23
21
20
June
26.6
25
28
27
28
July
28.2
28
28
27
30
August
27.0
26
27
29
27
September
24.6
24
23
25
24
October
17.6
18
18
20
16
November
9.2
12
12
9
13
December
5.0
8
4
8
4
Average
14.0
9.7
16.8
16.5
16.5
16.3
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
-4.1
-4
-1
-9
-3
-1
February
-4.7
-2
-2
-5
-9
-3
March
0.3
2
0
1
1
2
April
4.8
8
4
4
5
4
May
11.1
9
12
9
10
June
15.8
13
15
18
16
July
18.2
16
18
18
19
August
16.6
16
17
18
15
September
13.8
13
13
14
12
October
7.9
8
5
11
6
November
0.8
0
1
0
3
December
-2.6
2
-1
0
-2
Average
5.1
0.9
6.4
6.2
6.9
7.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
16.3
23
20
10
11
16
February
13.4
4
8
15
18
19
March
9.1
5
11
7
4
12
April
9.4
6
8
10
7
10
May
7.6
4
8
6
12
June
5.0
5
2
7
3
July
4.2
2
7
3
4
August
2.3
3
2
1
2
September
4.2
1
2
6
2
October
8.2
9
1
8
9
November
8.5
4
8
8
10
December
9.7
8
3
8
5
Average
8.9
9.0
6.4
6.0
6.8
7.5
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
8.4
9
8
8
8
8
February
8.8
8
10
9
8
9
March
9.2
10
10
10
9
8
April
8.8
9
9
10
9
9
May
7.6
7
8
7
8
June
6.6
6
6
7
7
July
5.1
5
6
5
5
August
5.0
5
5
4
5
September
5.5
5
6
7
6
October
7.3
7
9
7
7
November
8.5
8
9
8
10
December
7.9
7
7
9
7
Average
7.7
8.9
7.0
7.6
7.2
7.0
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
228°
233°
245°
240°
217°
February
233°
227°
218°
277°
261°
March
226°
243°
233°
224°
232°
April
237°
225°
216°
235°
249°
May
048°
176°
253°
219°
June
318°
251°
222°
233°
July
245°
220°
252°
236°
August
245°
218°
220°
265°
September
111°
269°
234°
204°
October
235°
226°
219°
219°
November
226°
216°
224°
227°
December
218°
202°
205°
245°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.