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
74.2
66
71
77
89
84
February
80.9
80
76
81
85
89
March
85.4
86
80
74
96
91
April
85.4
90
84
86
88
90
May
92.1
95
94
94
95
June
93.3
84
93
95
98
July
94.1
89
97
93
98
August
95.3
90
95
96
98
September
94.2
91
94
95
97
October
91.1
94
96
84
94
November
91.1
92
89
95
94
December
80.4
62
89
84
88
Average
88.0
80.9
84.5
89.0
91.5
93.4
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
-2.5
-1
0
-5
-1
1
February
0.4
5
2
-1
-2
0
March
4.2
7
3
3
9
6
April
10.4
13
12
9
12
10
May
18.4
19
21
19
17
June
24.3
25
25
26
26
July
27.0
26
26
26
29
August
25.7
24
26
28
26
September
21.8
23
22
22
20
October
14.5
15
15
18
11
November
6.5
7
9
7
11
December
1.5
5
2
3
1
Average
11.9
5.6
13.3
13.0
13.8
13.0
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
-9.8
-6
-4
-14
-6
-5
February
-10.7
-5
-8
-12
-13
-9
March
-6.8
-3
-5
-5
-4
-4
April
0.2
2
2
-1
1
-2
May
5.9
5
8
5
5
June
11.5
11
11
14
11
July
14.9
14
14
15
16
August
14.3
13
14
16
15
September
10.5
11
11
10
9
October
5.1
7
3
8
3
November
-2.6
-2
0
-2
2
December
-5.5
-1
-3
-4
-4
Average
2.1
-3.1
3.7
2.4
3.5
3.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
21.5
23
24
28
9
13
February
16.4
14
23
15
12
10
March
14.4
15
23
23
5
9
April
14.5
16
20
13
7
10
May
7.8
8
7
6
10
June
6.7
6
6
7
4
July
4.3
9
3
7
3
August
5.2
7
7
3
6
September
5.8
3
6
6
5
October
13.5
19
16
8
14
November
13.2
16
17
11
4
December
14.8
17
14
10
11
Average
11.5
16.9
13.9
12.2
7.2
7.8
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
7.1
7
7
8
7
7
February
8.3
7
9
9
8
8
March
8.7
9
8
9
10
8
April
8.7
10
8
8
8
9
May
7.8
7
8
8
8
June
6.8
7
7
7
7
July
6.3
5
6
7
6
August
6.3
7
6
6
6
September
6.6
6
7
7
7
October
7.5
7
7
6
7
November
7.5
8
8
7
8
December
7.4
7
8
8
8
Average
7.5
8.2
7.1
7.6
7.3
7.4
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
269°
079°
281°
291°
256°
February
267°
271°
307°
260°
274°
March
288°
340°
279°
270°
225°
April
358°
203°
188°
002°
322°
May
067°
115°
023°
033°
June
041°
277°
174°
154°
July
025°
258°
004°
324°
August
338°
319°
178°
312°
September
107°
305°
239°
230°
October
281°
230°
080°
255°
November
242°
220°
235°
238°
December
337°
194°
227°
271°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.