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
79.2
71
65
98
68
79
February
90.2
96
86
94
90
93
March
90.2
90
84
91
93
89
April
90.6
90
86
85
96
May
93.6
95
97
91
97
June
96.5
98
99
98
99
July
95.0
97
94
94
96
August
93.4
96
93
91
98
September
90.1
87
95
96
90
October
90.2
92
99
85
93
November
89.9
100
83
95
94
December
79.5
64
79
83
86
Average
89.9
85.8
88.1
92.9
89.4
92.9
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
-5.2
-4
-3
-8
-3
-4
February
-4.8
5
-2
-6
-8
-2
March
4.2
7
2
3
8
5
April
10.0
10
9
12
12
May
20.0
23
20
20
18
June
25.5
27
26
28
26
July
27.0
27
27
28
28
August
24.7
27
26
28
25
September
20.7
23
22
23
19
October
12.0
14
15
16
9
November
3.3
5
5
5
8
December
-2.6
3
-2
-1
-1
Average
10.8
2.6
12.9
11.8
12.9
12.0
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
-14.5
-9
-11
-20
-11
-11
February
-15.2
-6
-14
-18
-18
-14
March
-6.3
-5
-9
-7
-2
-3
April
-1.2
-1
0
1
-1
May
6.5
7
6
7
7
June
12.4
14
12
14
13
July
14.3
13
13
14
15
August
13.4
13
14
15
14
September
10.0
11
10
10
8
October
3.4
5
3
6
0
November
-4.4
-2
-4
-3
-2
December
-10.7
-4
-9
-11
-10
Average
0.5
-7.1
1.9
0.3
1.6
1.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.8
3
20
4
8
14
February
9.7
3
7
11
11
6
March
9.0
10
17
7
10
9
April
11.7
15
16
14
7
May
6.0
2
9
1
7
June
3.8
4
3
2
2
July
3.3
1
3
4
3
August
3.7
1
3
3
4
September
4.7
5
4
1
2
October
8.2
7
6
2
10
November
8.8
1
16
3
6
December
11.7
9
14
11
9
Average
7.2
5.8
7.5
7.3
5.6
6.0
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
5.3
6
5
6
4
4
February
6.2
7
4
7
6
6
March
6.4
7
6
7
6
6
April
7.3
8
9
6
7
May
6.2
6
7
6
6
June
6.0
5
7
6
7
July
4.5
5
6
4
4
August
4.9
5
5
5
5
September
5.2
5
5
5
5
October
6.1
7
7
4
6
November
5.7
6
7
4
5
December
4.9
5
5
3
5
Average
5.9
6.8
5.7
6.4
4.9
5.6
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
265°
305°
239°
319°
273°
February
259°
242°
284°
249°
263°
March
317°
347°
315°
205°
260°
April
323°
280°
321°
305°
May
069°
207°
229°
358°
June
037°
237°
247°
174°
July
281°
247°
176°
215°
August
192°
201°
204°
204°
September
136°
201°
229°
235°
October
299°
234°
200°
248°
November
257°
250°
276°
210°
December
246°
163°
261°
283°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.