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
90.1
89
83
98
85
94
February
86.4
81
87
96
90
95
March
83.7
80
86
93
89
86
April
90.7
91
93
93
89
96
May
88.0
87
94
91
95
June
95.2
93
95
100
97
July
96.8
96
100
93
98
August
96.8
99
97
97
99
September
94.9
96
98
98
98
October
90.7
87
96
91
89
November
93.0
95
96
99
99
December
87.5
95
70
95
93
Average
91.0
85.1
91.5
94.7
93.2
95.1
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
2.7
0
-1
5
4
4
February
2.1
8
1
5
-3
4
March
8.9
10
5
11
11
11
April
14.9
16
15
15
16
15
May
20.1
22
21
19
20
June
28.0
26
29
30
30
July
31.2
29
33
32
32
August
29.9
29
31
32
32
September
26.1
26
28
28
25
October
15.5
16
17
18
14
November
10.1
11
6
13
13
December
4.3
7
0
6
7
Average
15.8
8.3
15.5
17.3
17.2
17.6
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
-9.2
-12
-9
-9
-7
-7
February
-11.3
-5
-11
-10
-14
-6
March
-5.3
-4
-8
-5
-2
-2
April
-1.4
1
-1
-1
-1
-1
May
6.2
8
5
5
6
June
12.1
12
11
14
12
July
15.7
14
16
16
16
August
13.7
15
15
14
14
September
9.7
10
10
10
8
October
0.6
1
0
3
-1
November
-5.8
-4
-8
-2
-4
December
-8.4
-6
-12
-7
-7
Average
1.5
-6.7
1.7
1.4
2.4
2.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
6.7
7
11
4
8
5
February
12.0
10
9
4
14
13
March
7.0
7
8
5
8
5
April
8.6
12
7
7
10
6
May
5.9
4
5
2
5
June
2.4
2
2
3
1
July
1.1
3
1
1
1
August
1.2
1
2
1
0
September
2.0
2
1
2
1
October
4.4
7
1
2
7
November
3.9
5
3
1
2
December
9.4
7
23
5
3
Average
5.4
8.9
5.1
3.9
4.6
3.7
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
8.7
7
7
12
9
8
February
9.0
9
10
12
7
10
March
9.7
10
9
11
10
10
April
11.1
11
11
14
10
10
May
8.9
8
9
9
9
June
7.7
7
8
8
9
July
7.1
5
8
8
8
August
7.1
7
6
8
8
September
7.7
6
8
8
8
October
9.6
8
9
10
9
November
9.0
8
10
10
9
December
9.1
10
9
8
10
Average
8.7
9.5
8.0
9.5
8.6
8.9
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
293°
284°
294°
297°
260°
February
288°
280°
296°
271°
295°
March
312°
302°
322°
285°
283°
April
304°
319°
310°
323°
309°
May
192°
300°
112°
175°
June
176°
233°
196°
287°
July
325°
225°
155°
163°
August
296°
197°
217°
187°
September
270°
258°
290°
296°
October
302°
311°
300°
296°
November
288°
294°
286°
260°
December
296°
304°
264°
298°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.