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
89.8
85
90
80
99
96
February
94.6
92
99
95
93
98
March
98.0
92
98
99
99
100
April
99.0
98
98
100
99
May
99.4
100
99
99
99
June
99.1
100
97
100
98
July
99.7
100
100
100
100
August
98.8
99
100
98
99
September
98.0
99
100
94
100
October
98.1
93
99
99
100
November
94.7
97
91
83
97
December
83.5
80
79
87
91
Average
95.9
89.6
96.2
95.6
95.9
98.4
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
3.4
4
3
0
5
6
February
6.5
10
6
5
6
8
March
12.3
12
7
14
14
13
April
17.3
16
15
19
19
May
23.1
24
20
23
24
June
28.7
26
28
33
28
July
35.7
36
36
37
34
August
34.0
33
36
32
35
September
27.9
27
31
28
29
October
17.6
19
21
18
18
November
9.5
10
5
11
10
December
3.1
6
0
4
3
Average
17.1
8.5
17.9
18.1
19.4
19.1
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
-4.0
-4
-5
-6
-2
-1
February
-4.8
0
-6
-6
-3
-4
March
-1.6
0
-2
0
-2
0
April
2.6
1
0
3
3
May
7.4
9
5
8
8
June
12.0
12
11
16
11
July
16.7
17
17
19
15
August
15.7
16
17
15
16
September
10.0
10
11
9
10
October
2.7
4
3
5
2
November
-2.4
-1
-5
1
-2
December
-4.2
-2
-6
-3
-6
Average
3.8
-2.6
4.5
3.8
5.4
4.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.2
18
13
12
4
11
February
7.5
14
5
3
7
7
March
6.7
6
15
4
4
6
April
5.9
9
12
3
1
May
7.7
11
10
4
8
June
4.5
5
9
3
8
July
1.1
3
1
1
1
August
1.6
5
4
1
0
September
2.4
7
2
2
1
October
4.6
10
1
8
3
November
6.5
10
9
5
9
December
8.6
9
16
10
4
Average
6.2
12.4
8.3
6.7
4.1
4.7
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
9.4
11
10
8
7
9
February
11.2
11
13
11
10
11
March
10.5
9
13
12
11
8
April
11.4
13
12
10
10
May
9.3
8
10
11
9
June
9.2
8
9
10
10
July
7.9
8
8
8
9
August
8.0
9
8
9
9
September
7.8
8
8
9
8
October
8.5
9
7
10
9
November
8.9
8
9
9
9
December
8.3
8
8
10
7
Average
9.3
10.3
9.4
9.2
9.6
9.0
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
096°
085°
109°
090°
104°
February
059°
074°
078°
337°
333°
March
323°
072°
353°
347°
329°
April
316°
357°
328°
330°
May
058°
331°
322°
331°
June
294°
344°
344°
320°
July
317°
340°
020°
329°
August
036°
083°
329°
325°
September
004°
075°
349°
352°
October
039°
351°
067°
322°
November
076°
078°
100°
094°
December
103°
096°
106°
103°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.