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
74.4
65
74
86
73
February
86.1
87
89
80
82
96
March
87.9
90
79
90
93
83
April
86.0
86
79
81
99
May
93.7
95
96
93
96
June
96.1
95
97
99
98
July
95.8
99
95
94
97
August
93.7
96
93
93
95
September
92.8
89
94
95
98
October
86.8
88
98
84
89
November
91.7
98
85
95
92
December
76.5
59
82
83
76
Average
88.3
81.7
88.2
90.3
89.5
93.0
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
-7.4
-6
-5
-9
-3
February
-5.2
3
-4
-7
-9
-4
March
2.7
5
-1
1
8
4
April
9.8
8
6
11
10
May
19.2
22
19
20
17
June
25.7
27
26
29
26
July
26.6
27
27
28
27
August
24.4
27
25
27
25
September
21.1
25
22
23
19
October
11.2
13
15
15
8
November
4.1
6
3
4
6
December
-3.7
2
-4
-3
-1
Average
9.9
0.7
11.8
10.7
12.5
12.9
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
-15.0
-12
-12
-21
-11
February
-15.1
-6
-15
-20
-18
-14
March
-7.8
-5
-11
-7
-2
-4
April
0.1
-1
-1
1
-1
May
7.7
8
7
7
7
June
13.7
14
14
15
14
July
15.3
14
16
16
16
August
14.2
14
14
15
15
September
10.5
15
10
10
8
October
3.0
4
3
6
0
November
-4.1
-4
-5
-4
-3
December
-10.1
-4
-11
-13
-10
Average
0.3
-8.3
1.3
0.3
1.8
3.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
11.1
16
19
6
13
February
8.6
4
7
10
8
5
March
8.8
7
18
7
8
7
April
11.4
16
18
13
4
May
4.3
2
3
3
8
June
2.9
2
2
4
5
July
3.3
3
3
2
2
August
2.9
1
3
3
2
September
4.7
4
2
6
4
October
7.9
6
3
7
11
November
6.5
4
18
2
3
December
13.4
18
16
14
10
Average
7.1
8.9
7.9
6.8
6.4
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
6.6
7
6
8
6
February
7.6
8
7
9
7
7
March
8.0
9
8
8
9
8
April
8.9
8
11
9
8
May
8.1
8
9
8
7
June
7.3
6
9
7
6
July
5.7
6
7
5
5
August
6.7
7
6
7
6
September
7.2
7
7
7
7
October
7.9
8
8
7
8
November
8.4
8
9
9
9
December
7.1
7
6
7
7
Average
7.5
8.0
7.1
8.1
7.3
7.0
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
276°
310°
278°
310°
February
273°
264°
299°
274°
280°
March
333°
013°
333°
171°
288°
April
353°
298°
330°
316°
May
132°
212°
193°
026°
June
117°
239°
254°
160°
July
291°
261°
188°
236°
August
201°
187°
207°
176°
September
139°
214°
224°
264°
October
298°
246°
148°
273°
November
261°
279°
274°
239°
December
237°
159°
266°
290°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.