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
77.3
69
66
83
76
85
February
86.0
93
88
84
88
95
March
90.5
85
83
92
94
100
April
83.5
84
77
87
100
May
90.6
92
88
91
95
June
94.2
92
93
94
97
July
95.9
98
92
94
97
August
88.6
88
91
86
82
September
88.2
83
87
98
92
October
90.2
91
96
84
94
November
89.3
94
78
96
93
December
77.8
72
75
74
86
Average
87.9
82.8
86.6
87.3
89.0
92.3
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
-6.8
-5
-4
-9
-3
-5
February
-4.9
2
-3
-7
-3
-6
March
2.8
4
1
1
6
0
April
8.3
7
4
10
13
May
17.3
18
16
18
16
June
22.7
23
22
25
23
July
25.4
24
24
26
26
August
23.6
24
23
26
23
September
19.4
20
20
21
18
October
11.0
11
13
15
8
November
2.8
4
4
4
6
December
-2.0
2
-1
-2
-2
Average
9.3
0.4
10.6
9.6
12.3
11.0
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
-14.7
-11
-11
-19
-12
-10
February
-13.0
-8
-14
-18
-10
-14
March
-7.3
-6
-9
-8
-4
-2
April
-2.6
-2
-3
-1
8
May
5.3
6
6
5
6
June
10.2
11
8
13
11
July
13.7
12
13
13
15
August
13.0
12
13
14
14
September
9.5
11
9
10
7
October
2.9
4
2
6
-1
November
-5.6
-4
-1
-5
-4
December
-10.1
-4
-8
-12
-11
Average
-1.6
-9.8
1.0
0.0
1.9
1.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.6
13
19
15
12
13
February
15.2
3
16
21
12
10
March
8.3
12
15
9
7
0
April
14.1
17
19
12
0
May
7.0
3
14
5
3
June
4.0
5
4
2
1
July
2.8
3
4
0
5
August
4.4
5
2
0
3
September
5.7
11
6
2
2
October
9.0
9
4
5
10
November
10.9
5
23
4
9
December
16.2
16
22
20
8
Average
8.6
9.4
9.7
10.3
5.8
5.3
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
5.6
5
5
7
5
6
February
6.7
7
7
7
6
7
March
7.1
7
8
7
7
8
April
7.3
8
8
6
6
May
6.9
8
7
7
7
June
6.0
6
7
5
6
July
4.7
4
6
5
4
August
5.2
5
5
7
5
September
5.5
5
5
5
6
October
6.3
6
6
5
7
November
6.1
6
6
7
6
December
5.5
5
6
7
5
Average
6.1
6.5
6.0
6.4
5.9
5.7
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
263°
289°
268°
251°
260°
February
279°
270°
274°
237°
246°
March
317°
053°
303°
089°
270°
April
033°
039°
124°
121°
May
066°
088°
130°
061°
June
083°
247°
171°
040°
July
270°
260°
109°
200°
August
094°
194°
216°
099°
September
090°
173°
227°
246°
October
350°
277°
078°
250°
November
254°
250°
275°
245°
December
305°
093°
269°
271°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.