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
57.9
49
56
44
72
71
February
75.6
56
85
82
88
89
March
89.4
91
87
84
97
92
April
93.2
94
92
99
95
May
96.0
95
92
99
92
June
97.3
100
90
100
95
July
99.6
100
100
100
100
August
96.3
92
100
90
100
September
90.6
96
93
97
75
October
93.5
92
94
91
94
November
70.8
53
69
81
81
December
53.4
48
29
68
39
Average
84.1
64.4
83.7
83.1
91.8
87.6
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
0.9
0
1
0
3
3
February
2.8
5
4
5
2
6
March
9.0
11
7
11
12
9
April
13.4
13
11
17
15
May
20.4
24
16
21
19
June
24.7
26
23
31
23
July
30.7
31
31
34
30
August
30.1
29
32
30
31
September
23.4
23
26
24
26
October
14.2
16
19
15
13
November
5.2
5
1
8
6
December
1.1
4
-3
0
2
Average
13.6
5.3
15.2
15.0
16.5
15.2
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
-4.1
-5
-3
-5
-1
-2
February
-5.5
-1
-5
-5
-5
-3
March
-1.0
1
-2
1
-1
-1
April
1.9
1
-1
2
2
May
7.3
10
4
6
7
June
10.7
12
10
15
10
July
14.1
14
15
17
12
August
14.0
15
15
14
13
September
9.4
9
10
9
10
October
3.0
4
6
3
2
November
-2.5
-1
-6
1
-1
December
-4.4
-1
-8
-5
-2
Average
3.1
-2.1
4.4
3.5
4.5
3.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
19.0
31
19
13
24
25
February
21.2
27
16
13
14
8
March
13.4
12
15
20
4
14
April
12.1
14
13
5
6
May
6.9
5
12
5
14
June
5.5
5
13
1
9
July
1.1
1
3
1
1
August
2.5
10
1
1
1
September
5.9
8
5
5
2
October
8.0
7
10
10
11
November
15.0
16
22
15
11
December
18.8
28
19
19
14
Average
11.4
23.6
11.5
11.5
7.1
9.0
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
6.6
7
5
5
8
10
February
8.0
8
9
7
10
9
March
8.5
7
8
8
9
10
April
9.5
9
11
10
8
May
7.8
6
9
9
9
June
7.7
7
8
7
8
July
6.9
7
6
6
8
August
7.0
7
7
8
7
September
7.0
8
6
7
7
October
7.4
6
7
8
9
November
7.2
7
7
9
8
December
5.8
6
3
9
5
Average
7.5
7.4
7.0
7.3
8.2
8.2
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
116°
076°
179°
166°
196°
February
209°
197°
180°
223°
218°
March
204°
130°
212°
207°
210°
April
209°
195°
180°
213°
May
180°
210°
211°
166°
June
210°
207°
173°
191°
July
217°
209°
180°
195°
August
203°
186°
196°
197°
September
181°
124°
190°
178°
October
133°
202°
158°
202°
November
170°
094°
165°
173°
December
096°
145°
209°
120°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.