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
76.7
67
73
76
78
65
February
81.3
80
67
86
77
89
March
88.7
89
96
75
90
88
April
92.4
76
92
96
99
May
97.6
96
97
99
99
June
99.1
97
98
99
100
July
98.9
98
100
97
99
August
90.9
96
99
93
99
September
94.0
98
99
96
79
October
91.6
93
89
88
88
November
84.4
90
89
72
73
December
74.1
61
83
82
73
Average
89.0
79.5
87.3
91.5
90.3
88.9
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
-1.9
-1
1
0
1
-1
February
1.3
4
1
3
0
3
March
6.5
8
6
7
7
6
April
10.8
9
9
13
12
May
18.9
22
13
18
18
June
20.9
23
19
24
19
July
25.5
27
25
28
24
August
26.0
27
28
25
23
September
19.4
19
23
18
21
October
11.2
12
17
9
11
November
3.6
5
1
4
3
December
-1.6
3
-4
-3
1
Average
10.9
3.4
12.1
12.4
12.0
11.6
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
-4.3
-4
-2
-4
-2
-5
February
-5.5
-1
-3
-3
-5
-3
March
-2.1
-1
-1
0
-2
-3
April
0.9
1
0
0
1
May
5.5
9
4
4
6
June
9.0
11
9
10
8
July
11.4
13
13
12
10
August
11.7
12
14
12
10
September
8.2
9
9
8
9
October
3.3
5
6
3
4
November
-1.2
0
-4
0
-1
December
-4.3
0
-8
-7
-2
Average
2.3
-3.8
4.1
3.6
2.9
2.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
30.7
31
21
32
35
45
February
24.4
21
33
16
29
25
March
18.8
13
7
27
19
18
April
19.3
27
20
14
11
May
9.5
1
19
8
8
June
12.7
8
15
10
23
July
6.2
7
7
1
10
August
3.8
5
1
5
8
September
14.6
16
5
21
8
October
19.2
14
10
32
22
November
26.8
14
18
43
33
December
28.4
26
29
24
29
Average
17.3
20.7
14.7
15.4
18.4
18.4
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
1.1
1
1
1
1
1
February
1.9
1
2
2
2
2
March
1.9
1
2
2
2
2
April
2.0
2
2
2
2
May
2.0
2
2
2
2
June
2.2
2
2
2
2
July
2.1
2
2
2
2
August
2.0
2
2
2
2
September
1.8
2
2
2
2
October
1.6
1
2
2
2
November
1.3
1
1
1
1
December
1.0
1
1
2
1
Average
1.7
1.2
1.6
1.8
1.8
1.9
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
114°
360°
195°
262°
141°
February
137°
167°
166°
163°
179°
March
180°
138°
172°
175°
166°
April
180°
161°
157°
170°
May
187°
184°
175°
170°
June
174°
182°
178°
181°
July
180°
175°
182°
182°
August
180°
181°
178°
182°
September
176°
161°
178°
180°
October
062°
185°
169°
170°
November
177°
028°
182°
167°
December
173°
005°
156°
177°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.