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
76.1
64
80
68
85
69
February
87.1
79
92
87
96
91
March
94.2
94
93
93
100
93
April
96.3
95
95
100
96
May
97.0
97
97
98
95
June
96.0
98
95
100
88
July
97.9
100
86
100
100
August
95.4
93
100
89
100
September
92.1
96
95
97
84
October
95.2
91
92
98
100
November
84.7
82
82
81
December
76.9
65
77
83
30
Average
89.6
79.7
91.2
88.9
94.2
90.1
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
0.2
-1
1
1
2
0
February
2.4
4
2
2
1
7
March
8.4
10
7
9
10
8
April
12.5
13
10
16
13
May
20.5
23
18
20
18
June
22.1
26
23
25
18
July
28.3
31
26
33
23
August
28.7
30
31
27
29
September
22.7
22
24
21
24
October
13.3
14
16
14
20
November
3.3
4
1
4
December
0.0
2
-3
0
-1
Average
12.4
4.3
14.6
12.9
14.3
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
-5.6
-7
-3
-5
-3
-4
February
-5.8
-1
-5
-6
-3
-1
March
-1.0
-1
-3
0
0
-2
April
1.4
2
-1
1
1
May
7.4
10
12
6
6
June
10.1
11
9
10
8
July
13.7
13
11
16
23
August
13.1
14
14
12
13
September
8.3
9
9
7
9
October
2.5
3
4
3
5
November
-2.0
-2
-5
0
December
-4.4
-2
-6
-5
-3
Average
2.8
-3.1
3.9
2.4
3.5
4.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
11.7
18
6
14
9
32
February
11.0
13
12
11
0
6
March
5.5
11
12
1
0
8
April
3.7
6
4
1
5
May
1.6
1
6
1
3
June
2.2
2
3
2
1
July
0.3
0
0
0
0
August
1.2
3
0
3
0
September
0.9
2
1
1
0
October
1.6
2
3
2
0
November
9.5
12
19
10
December
18.7
16
23
20
50
Average
6.2
13.5
5.5
6.1
3.8
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
1.8
1
1
2
2
3
February
3.0
2
3
3
3
4
March
3.5
2
3
4
5
4
April
4.0
3
5
4
4
May
3.5
2
3
4
4
June
3.8
3
4
5
5
July
3.0
3
2
3
6
August
3.0
3
3
3
4
September
2.8
2
2
3
3
October
2.3
2
2
3
1
November
1.7
2
1
3
December
2.0
1
2
3
2
Average
2.8
1.5
2.3
2.9
3.3
3.6
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
125°
205°
197°
217°
205°
February
215°
205°
200°
210°
190°
March
215°
231°
206°
201°
197°
April
201°
189°
184°
194°
May
288°
194°
218°
204°
June
196°
209°
199°
215°
July
199°
199°
191°
210°
August
207°
218°
224°
197°
September
276°
226°
197°
204°
October
244°
201°
197°
180°
November
264°
282°
190°
December
232°
261°
199°
344°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.