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
82.0
72
83
97
74
78
February
88.8
83
91
92
88
95
March
86.3
89
81
96
88
90
April
91.5
86
97
94
94
97
May
93.0
92
98
93
94
June
98.5
99
98
100
99
July
96.2
98
96
86
100
August
94.1
94
96
96
96
September
92.4
91
100
94
95
October
90.8
87
100
87
90
November
93.3
100
93
97
98
December
85.5
80
69
95
90
Average
90.6
83.0
91.3
95.1
91.4
93.8
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
-2.9
-5
-2
1
2
-1
February
0.8
7
0
3
-4
3
March
7.4
9
2
9
13
8
April
14.5
15
15
14
15
15
May
21.7
25
21
21
19
June
28.8
29
27
32
29
July
30.5
29
30
31
30
August
29.0
30
29
31
30
September
25.9
27
28
26
25
October
15.5
16
19
17
13
November
9.3
11
6
11
13
December
2.6
6
-2
2
5
Average
14.4
6.6
15.6
16.1
16.4
15.5
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
-11.9
-12
-11
-12
-6
-8
February
-11.9
-4
-11
-12
-14
-7
March
-4.9
-4
-7
-5
-1
1
April
1.5
3
1
0
1
1
May
9.1
10
7
9
9
June
14.8
16
7
16
17
July
16.0
16
4
18
18
August
14.4
16
3
16
17
September
12.4
12
11
13
11
October
3.5
4
4
6
1
November
-3.2
-3
-5
-1
-2
December
-8.6
-5
-11
-8
-7
Average
2.3
-5.9
3.1
-1.5
4.1
4.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
6.8
3
11
3
7
6
February
9.0
5
6
6
6
3
March
7.7
3
10
4
12
7
April
7.8
12
6
13
8
5
May
7.1
2
2
6
11
June
3.8
4
4
2
4
July
2.0
2
2
3
2
August
3.5
4
3
2
2
September
4.6
5
1
8
1
October
7.8
11
4
6
8
November
4.5
1
7
4
1
December
9.8
9
26
6
8
Average
6.1
6.3
5.6
5.3
5.6
4.8
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
8.4
8
7
10
9
8
February
8.7
8
8
11
8
8
March
9.7
10
9
11
11
10
April
11.1
12
11
15
11
11
May
8.9
9
9
9
10
June
8.5
7
9
8
10
July
7.3
6
8
7
7
August
7.3
7
8
8
7
September
8.0
7
9
8
8
October
9.6
10
10
9
9
November
8.7
8
11
8
9
December
8.5
8
10
8
8
Average
8.9
9.9
8.0
9.9
8.7
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
297°
314°
300°
297°
262°
February
301°
316°
310°
297°
303°
March
335°
350°
328°
313°
067°
April
327°
323°
318°
325°
309°
May
141°
277°
134°
177°
June
170°
221°
171°
157°
July
135°
183°
138°
150°
August
181°
130°
149°
150°
September
139°
176°
202°
309°
October
318°
296°
290°
297°
November
300°
298°
303°
249°
December
296°
302°
313°
302°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.