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
79.3
64
77
97
73
71
February
89.7
83
88
97
87
94
March
81.6
87
79
95
81
71
April
90.3
90
96
95
90
94
May
89.5
90
93
92
91
June
95.6
97
93
100
96
July
95.3
98
93
91
99
August
92.7
94
91
99
97
September
92.6
93
96
93
96
October
88.4
81
98
85
90
November
91.6
96
94
99
94
December
83.9
84
54
97
88
Average
88.8
82.0
89.8
92.6
90.9
90.6
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
0.4
-4
-2
5
2
0
February
2.1
9
1
5
-4
5
March
9.1
10
5
10
13
11
April
15.6
16
17
16
16
16
May
21.2
24
21
21
19
June
28.7
28
29
30
30
July
30.1
29
32
30
30
August
29.0
30
31
31
31
September
25.9
27
28
27
25
October
16.2
16
20
18
15
November
10.3
12
8
13
13
December
3.8
6
0
7
6
Average
15.1
7.5
16.1
17.4
17.0
16.7
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
-9.0
-11
-9
-11
-5
-8
February
-9.0
-3
-9
-10
-14
-7
March
-3.7
-3
-5
-4
0
0
April
2.2
4
2
1
2
2
May
9.7
10
10
9
9
June
15.8
15
15
16
17
July
17.9
16
18
17
19
August
16.6
17
17
17
17
September
12.8
13
12
13
11
October
3.8
4
4
6
3
November
-3.8
-2
-5
0
-1
December
-7.7
-4
-9
-6
-6
Average
3.3
-4.5
4.1
3.5
4.7
4.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.7
11
15
5
8
7
February
7.6
8
6
4
12
3
March
5.9
5
5
1
10
8
April
5.1
7
3
6
3
2
May
7.0
4
4
3
11
June
3.3
5
2
1
2
July
2.1
3
3
2
1
August
2.4
4
2
1
0
September
2.0
2
1
2
1
October
5.1
12
1
2
5
November
4.1
5
1
4
4
December
8.3
7
19
3
8
Average
5.2
7.3
5.6
3.4
3.9
4.1
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
9.4
9
9
11
9
9
February
10.0
10
10
12
8
10
March
10.7
11
11
13
11
11
April
12.4
13
14
17
12
12
May
9.3
9
10
9
9
June
8.6
7
9
8
11
July
7.5
6
8
8
8
August
8.0
8
9
9
9
September
8.9
8
9
9
10
October
10.4
10
11
10
9
November
10.2
10
11
10
10
December
9.6
8
12
10
10
Average
9.7
10.7
9.0
10.9
9.4
9.7
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
296°
311°
283°
304°
280°
February
286°
282°
308°
285°
298°
March
333°
320°
331°
283°
232°
April
323°
308°
295°
317°
305°
May
162°
271°
120°
002°
June
167°
214°
186°
168°
July
235°
201°
163°
169°
August
207°
178°
161°
181°
September
180°
176°
197°
255°
October
308°
277°
277°
287°
November
266°
294°
291°
242°
December
291°
289°
294°
302°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.