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
65.6
54
38
72
82
60
February
88.3
84
87
80
91
96
March
95.0
96
95
98
99
97
April
98.2
99
98
97
100
100
May
99.3
100
100
100
100
June
99.2
100
98
100
100
July
98.5
100
100
92
100
August
90.2
90
100
84
97
September
91.3
99
76
99
76
October
98.3
98
100
96
96
November
87.1
89
71
92
88
December
75.4
58
74
86
62
Average
90.4
82.9
87.1
89.9
93.6
90.3
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
0.5
0
0
-1
3
2
February
3.1
8
2
2
3
8
March
11.4
14
9
13
14
12
April
17.0
18
16
14
20
19
May
24.0
27
20
24
24
June
27.9
29
26
32
27
July
33.9
34
34
37
33
August
33.2
33
36
32
33
September
25.8
26
29
25
28
October
16.8
17
22
16
16
November
5.9
7
0
8
6
December
0.9
4
-4
0
2
Average
15.9
9.7
17.2
16.5
17.9
17.3
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
-4
-3
-6
-1
-3
February
-5.6
1
-5
-6
-4
-3
March
0.0
1
-1
2
0
0
April
3.5
4
3
2
4
4
May
9.1
12
7
8
9
June
12.2
13
12
15
12
July
16.3
17
16
19
16
August
15.7
16
17
16
15
September
10.8
12
12
10
12
October
4.3
5
8
5
4
November
-1.1
0
-6
1
-1
December
-4.5
0
-9
-6
-2
Average
4.4
0.3
5.8
4.4
5.5
5.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.9
28
19
2
10
14
February
6.9
10
6
3
7
3
March
7.0
10
8
3
1
3
April
6.1
6
8
10
2
2
May
3.7
3
6
1
6
June
2.3
2
7
1
3
July
0.5
0
1
0
1
August
0.9
3
0
1
1
September
2.5
5
2
2
2
October
4.7
5
1
7
6
November
7.4
8
9
7
8
December
10.4
16
16
10
11
Average
6.0
13.7
6.9
4.5
3.5
4.6
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
4.4
4
2
4
4
6
February
6.8
8
5
5
8
5
March
6.8
7
6
7
7
10
April
7.4
7
7
8
8
8
May
6.8
7
7
7
6
June
7.1
7
7
7
8
July
7.4
8
7
8
8
August
7.2
8
7
7
7
September
6.8
7
7
7
6
October
6.8
6
7
7
6
November
5.5
4
6
6
5
December
5.0
3
7
8
3
Average
6.5
6.2
5.9
6.5
7.1
6.6
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
015°
325°
182°
255°
179°
February
001°
200°
352°
356°
145°
March
003°
342°
181°
173°
005°
April
340°
185°
242°
356°
360°
May
351°
195°
354°
005°
June
350°
339°
345°
005°
July
342°
355°
343°
349°
August
354°
352°
358°
004°
September
013°
006°
180°
128°
October
001°
015°
165°
344°
November
178°
346°
174°
193°
December
181°
350°
358°
164°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.