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
92.2
91
87
92
96
91
February
94.5
93
96
90
98
96
March
94.0
87
87
92
98
98
April
98.2
96
97
98
99
May
98.5
100
96
99
99
June
99.1
99
98
100
100
July
99.4
100
99
100
99
August
99.4
99
99
100
100
September
98.8
100
97
100
99
October
95.7
98
91
99
94
November
96.7
90
98
100
99
December
90.6
87
85
88
91
Average
96.0
90.1
95.2
94.9
98.2
97.4
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
1.4
2
1
0
2
1
February
4.2
6
3
3
3
3
March
9.7
10
6
9
10
11
April
15.4
14
15
16
15
May
20.9
22
21
21
23
June
27.3
24
28
29
27
July
30.8
31
30
31
31
August
29.4
29
29
29
31
September
25.9
25
27
26
26
October
16.4
18
16
16
19
November
9.0
10
6
12
9
December
2.3
3
1
4
1
Average
14.9
5.9
15.5
15.9
16.7
16.4
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
-12.7
-11
-9
-14
-11
-12
February
-9.3
-7
-12
-13
-7
-10
March
-5.8
-3
-6
-6
-5
-3
April
-1.1
-2
-1
-1
-1
May
3.3
4
3
3
4
June
7.7
7
8
8
9
July
11.4
11
12
13
11
August
10.0
11
11
9
10
September
5.6
5
7
6
4
October
-2.9
0
0
0
-2
November
-6.3
-6
-8
-4
-5
December
-12.9
-10
-12
-9
-13
Average
-2.8
-7.0
-1.6
-1.3
0.2
-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
12.7
8
21
15
5
13
February
10.8
7
11
12
10
11
March
9.3
16
18
12
4
6
April
5.9
9
6
3
5
May
5.2
4
8
6
3
June
2.6
6
3
2
2
July
1.7
1
2
2
2
August
2.4
2
3
4
2
September
2.0
3
4
3
1
October
6.3
5
10
4
5
November
5.4
1
10
3
5
December
12.5
6
22
23
11
Average
6.6
10.7
7.1
8.0
5.1
5.0
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
3.5
4
4
3
4
3
February
6.0
5
6
4
7
5
March
6.7
6
7
5
6
8
April
8.3
9
11
8
8
May
7.1
6
9
7
8
June
6.9
7
7
6
8
July
5.2
6
5
4
6
August
5.2
5
5
5
5
September
6.0
6
5
5
5
October
5.3
5
4
5
7
November
4.4
4
5
5
4
December
3.3
3
3
5
2
Average
5.7
5.0
5.6
5.5
5.6
6.0
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
256°
251°
260°
256°
250°
February
254°
246°
249°
256°
264°
March
240°
248°
257°
246°
246°
April
240°
252°
248°
253°
May
249°
250°
245°
252°
June
241°
253°
251°
244°
July
258°
254°
286°
256°
August
268°
277°
254°
247°
September
252°
247°
261°
253°
October
249°
249°
255°
258°
November
253°
247°
247°
253°
December
252°
257°
258°
271°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.