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
87.6
88
83
97
92
87
February
88.8
92
83
91
94
96
March
91.3
90
83
93
91
93
April
97.7
99
98
98
97
100
May
98.2
100
99
100
100
June
99.7
100
100
100
100
July
99.7
100
100
100
100
August
99.6
100
99
100
100
September
99.2
100
99
99
99
October
98.0
99
98
97
96
November
96.6
95
97
99
97
December
89.1
91
90
82
89
Average
95.4
92.2
94.7
97.0
96.1
96.7
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
2.9
3
1
4
3
2
February
4.6
6
4
5
4
5
March
9.0
9
5
9
8
10
April
15.2
16
14
16
16
16
May
20.1
20
22
21
22
June
26.1
23
26
27
26
July
28.4
31
28
28
28
August
27.3
28
26
27
29
September
23.7
23
24
25
24
October
16.2
18
15
15
19
November
9.9
10
7
13
10
December
4.2
5
2
4
4
Average
14.8
8.3
15.1
15.7
15.9
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
-10.5
-9
-10
-11
-10
-10
February
-9.5
-7
-11
-11
-9
-9
March
-4.0
-2
-6
-5
-5
-2
April
-2.9
-1
-2
-1
-1
-1
May
2.9
4
4
3
3
June
7.2
6
8
8
8
July
11.4
12
12
12
11
August
10.0
11
11
10
10
September
6.6
7
8
7
6
October
0.4
1
1
0
0
November
-5.5
-5
-7
-4
-3
December
-9.7
-7
-9
-7
-10
Average
-1.6
-5.1
0.0
0.4
0.3
0.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.2
13
24
5
10
9
February
13.1
9
18
11
11
5
March
9.4
11
18
9
10
8
April
2.5
1
3
3
3
1
May
3.3
2
0
5
2
June
1.9
1
4
3
1
July
2.2
1
4
2
3
August
2.0
1
4
1
2
September
2.8
3
6
5
1
October
3.7
1
5
4
4
November
4.9
7
4
1
7
December
12.4
6
17
26
10
Average
5.9
8.1
6.6
5.4
6.2
4.0
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
2.5
2
3
2
2
2
February
4.2
4
5
4
4
4
March
4.4
5
2
5
5
5
April
6.2
6
3
8
7
7
May
6.3
5
9
6
7
June
5.5
5
6
5
6
July
4.3
6
4
4
5
August
4.3
5
3
5
4
September
4.6
5
4
5
4
October
4.7
5
4
4
6
November
3.3
3
4
3
3
December
2.5
2
2
4
3
Average
4.5
4.4
4.2
4.6
4.5
4.8
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
211°
214°
202°
205°
212°
February
219°
219°
210°
211°
212°
March
218°
217°
223°
223°
224°
April
229°
239°
230°
230°
233°
May
229°
228°
233°
229°
June
232°
223°
227°
229°
July
237°
232°
256°
222°
August
222°
219°
226°
234°
September
221°
231°
222°
220°
October
222°
223°
219°
218°
November
217°
216°
217°
221°
December
218°
213°
221°
226°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.