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
73.1
49
69
73
84
85
February
80.5
84
84
76
77
75
March
84.1
81
75
78
95
88
April
88.9
91
92
89
89
May
91.6
96
90
97
92
June
93.2
81
96
95
98
July
94.4
87
98
90
97
August
97.5
93
98
99
99
September
94.4
96
83
98
96
October
90.6
94
97
81
94
November
88.5
88
79
94
93
December
80.6
70
78
87
87
Average
87.0
70.6
85.6
87.4
91.3
91.8
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
0.8
2
3
-2
0
2
February
2.9
6
5
2
-2
1
March
6.7
10
5
8
10
8
April
12.8
16
13
14
10
May
20.2
20
22
19
18
June
25.3
25
25
27
26
July
27.9
28
28
26
29
August
26.3
25
28
29
24
September
23.3
24
23
24
22
October
16.6
17
17
19
15
November
8.6
10
11
10
11
December
3.8
7
4
7
3
Average
13.5
5.9
15.4
15.3
15.2
14.1
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
-6.9
-3
-2
-10
-5
-4
February
-5.2
-3
-3
-7
-9
-5
March
-2.4
1
-1
-2
-2
0
April
3.0
5
3
3
1
May
9.3
8
11
8
8
June
15.2
15
15
17
15
July
17.8
19
18
17
19
August
16.6
17
18
19
11
September
13.1
14
14
15
11
October
8.0
10
6
12
6
November
1.1
1
3
2
3
December
-2.1
2
-1
0
-3
Average
5.0
-2.5
7.1
6.0
6.5
5.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
24.6
41
26
27
14
16
February
21.8
10
18
33
30
27
March
18.1
18
28
21
7
18
April
14.0
12
13
12
16
May
9.4
7
8
9
10
June
5.5
8
4
6
2
July
4.4
6
4
7
4
August
3.6
4
5
2
4
September
4.1
1
11
5
1
October
12.5
12
10
12
11
November
13.5
11
19
10
12
December
18.7
20
17
13
13
Average
13.0
23.6
12.1
13.1
9.8
10.4
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
10.2
10
9
10
9
10
February
11.8
10
14
13
11
11
March
11.1
11
12
12
11
10
April
10.3
10
10
9
11
May
8.8
8
9
8
9
June
8.7
7
9
10
9
July
7.9
8
9
8
8
August
8.2
8
8
7
9
September
8.0
7
8
9
10
October
9.4
9
9
8
10
November
10.6
10
11
10
12
December
9.9
8
10
11
11
Average
9.6
10.2
9.0
9.6
9.1
9.7
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
255°
254°
267°
285°
256°
February
253°
249°
256°
253°
254°
March
261°
271°
256°
257°
238°
April
238°
244°
273°
272°
May
258°
207°
260°
285°
June
352°
247°
227°
239°
July
238°
239°
266°
246°
August
271°
249°
240°
244°
September
285°
261°
248°
231°
October
256°
228°
231°
245°
November
249°
244°
243°
240°
December
257°
244°
235°
248°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.