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
68.6
61
71
66
82
February
85.7
84
91
70
89
March
95.3
97
91
100
April
98.5
98
98
100
May
97.8
98
98
98
June
98.6
100
97
100
July
99.1
100
98
100
August
93.2
89
100
91
September
97.8
96
99
98
October
91.8
94
94
89
89
November
81.6
79
82
84
83
December
72.9
66
83
79
68
Average
85.9
72.1
90.5
92.3
93.2
81.2
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
-1.9
-2
1
-1
2
February
2.5
4
2
0
2
March
9.8
9
10
11
April
13.9
13
12
17
May
20.4
24
17
21
June
25.9
26
24
29
July
31.9
31
31
34
August
30.5
30
33
29
September
23.3
22
26
22
October
14.7
14
19
14
12
November
3.6
3
1
6
5
December
-1.6
1
-4
1
0
Average
10.5
0.9
14.6
15.5
15.9
5.8
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
-5.5
-8
-4
-4
-2
February
-6.9
-2
-7
-8
-6
March
-3.3
-4
-1
-2
April
-1.9
0
-1
1
May
5.4
9
4
3
June
10.0
8
10
12
July
10.9
10
11
13
August
10.8
10
11
12
September
6.3
6
7
6
October
1.5
1
3
2
1
November
-3.0
-4
-7
0
-2
December
-7.8
-3
-10
-7
-5
Average
0.0
-5.0
1.9
2.2
2.7
-2.3
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
February
0.0
0
0
0
0
March
0.0
0
0
0
April
0.0
0
0
0
May
0.0
0
0
0
June
0.0
0
0
0
July
0.0
0
0
0
August
0.0
0
0
0
September
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
0.7
1
1
1
1
February
1.7
2
1
0
3
March
2.3
2
2
3
April
3.7
3
5
3
May
3.1
2
4
4
June
2.8
2
4
3
July
2.6
3
2
3
August
2.3
3
2
2
September
2.2
3
2
2
October
1.6
2
1
2
2
November
1.3
1
1
1
1
December
0.9
0
1
2
1
Average
1.9
1.5
2.0
2.3
2.3
1.4
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
273°
080°
272°
201°
February
215°
090°
108°
268°
March
235°
235°
207°
April
184°
194°
228°
May
218°
196°
207°
June
214°
229°
216°
July
220°
193°
192°
August
237°
235°
241°
September
219°
263°
226°
October
235°
214°
181°
165°
November
189°
297°
172°
211°
December
041°
313°
200°
311°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.