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
80.9
77
86
73
87
February
90.1
90
97
87
87
March
92.1
93
87
94
96
April
97.7
97
98
96
99
May
96.5
99
91
99
June
99.2
99
99
99
July
99.8
100
99
100
August
99.3
99
100
99
September
99.0
99
100
98
October
95.8
92
99
97
November
89.9
90
90
December
83.7
86
83
81
94
Average
93.5
89.7
94.9
93.4
95.4
94.1
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
1.4
2
1
-2
4
February
3.9
7
4
0
5
March
9.8
10
5
12
13
April
15.7
17
15
14
18
May
21.8
24
20
22
June
28.7
25
28
33
July
35.3
35
35
36
August
32.4
32
35
31
September
27.3
26
30
27
October
18.3
18
20
17
November
6.2
8
5
December
2.8
5
0
2
0
Average
12.2
8.8
16.6
16.9
18.9
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
-5.1
-4
-5
-8
-3
February
-5.1
-1
-6
-9
-4
March
-2.5
-1
-3
0
-1
April
1.5
2
1
1
2
May
7.1
10
5
7
June
11.7
10
11
14
July
17.1
17
17
18
August
15.5
15
18
14
September
10.6
11
12
9
October
5.2
5
5
6
November
-3.2
-1
-4
December
-4.3
-2
-6
-4
-5
Average
1.6
-2.9
4.4
3.7
5.4
-5.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
6.2
13
5
4
4
February
4.8
6
7
2
4
March
6.0
7
15
1
3
April
2.5
2
3
5
1
May
0.9
1
2
1
June
1.1
1
2
1
July
0.0
0
0
0
August
0.6
1
0
0
September
0.8
1
0
1
October
3.2
4
0
5
November
5.6
7
4
December
9.4
8
7
14
0
Average
3.0
6.7
3.9
2.0
2.6
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
10.1
12
10
10
9
February
11.6
12
13
10
12
March
10.8
10
13
10
10
April
12.2
13
13
12
11
May
9.8
8
11
10
June
8.8
8
10
9
July
7.2
7
7
7
August
7.9
8
8
8
September
8.2
8
9
8
October
8.8
9
9
9
November
9.2
8
10
December
9.7
10
9
10
9
Average
9.7
11.6
9.5
9.4
9.4
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
072°
068°
083°
071°
February
011°
047°
081°
270°
March
278°
012°
268°
271°
April
263°
281°
273°
270°
May
131°
267°
261°
June
244°
263°
243°
July
237°
229°
178°
August
143°
151°
239°
September
215°
123°
245°
October
088°
229°
081°
November
093°
064°
December
079°
081°
264°
083°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.