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
83.7
83
87
83
90
72
February
82.6
83
83
93
78
100
March
89.7
83
82
90
97
93
April
92.0
91
87
97
92
May
98.1
99
98
98
97
June
98.3
98
97
100
99
July
99.5
99
100
99
100
August
97.9
99
96
97
99
September
98.6
98
97
100
99
October
97.6
99
99
97
99
November
91.3
98
85
88
91
December
84.5
87
85
72
85
Average
91.6
82.9
93.7
93.1
93.5
94.6
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
-3.0
-2
-4
-5
-2
-2
February
-2.6
2
-3
-2
-1
-3
March
4.3
5
2
6
5
5
April
9.7
8
10
11
10
May
17.3
19
16
18
18
June
23.4
21
24
28
21
July
29.3
29
31
31
28
August
27.6
26
28
27
29
September
22.8
22
25
24
23
October
13.6
15
16
14
16
November
4.5
6
-1
7
4
December
-2.3
0
-4
1
-4
Average
8.8
1.5
11.8
12.5
13.4
12.8
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
-11.1
-8
-11
-14
-12
-7
February
-11.0
-6
-13
-13
-9
-18
March
-7.1
-7
-9
-6
-9
-4
April
-3.9
-4
-2
-2
-2
May
3.6
5
3
4
4
June
7.9
7
7
9
7
July
11.3
12
11
12
10
August
10.5
11
11
9
12
September
5.7
6
6
3
7
October
-1.6
1
-1
1
0
November
-6.7
-4
-10
-2
-6
December
-10.6
-9
-12
-6
-13
Average
-3.3
-8.9
-1.5
-2.6
-1.9
0.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
0.0
0
0
0
0
0
February
0.0
0
0
0
0
0
March
0.0
0
0
0
0
0
April
0.0
0
0
0
0
May
0.0
0
0
0
0
June
0.0
0
0
0
0
July
0.0
0
0
0
0
August
0.0
0
0
0
0
September
0.0
0
0
0
0
October
0.0
0
0
0
0
November
0.0
0
0
0
0
December
0.0
0
0
0
0
Average
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
3.0
3
2
3
2
4
February
3.6
3
3
3
5
3
March
3.8
3
5
4
4
4
April
4.5
4
5
5
4
May
5.3
5
6
6
5
June
4.6
4
5
5
5
July
4.3
4
4
4
5
August
4.0
4
3
4
4
September
3.8
4
4
4
4
October
4.3
4
4
4
5
November
3.7
4
4
3
4
December
3.4
3
4
4
3
Average
3.9
3.2
3.8
4.2
4.1
4.3
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
242°
261°
257°
275°
248°
February
246°
291°
322°
284°
286°
March
272°
237°
293°
289°
217°
April
267°
287°
310°
288°
May
156°
280°
278°
232°
June
225°
243°
270°
231°
July
235°
263°
229°
264°
August
218°
234°
263°
272°
September
196°
257°
274°
283°
October
296°
291°
254°
280°
November
137°
262°
263°
184°
December
189°
319°
254°
306°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.