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
75.8
66
64
82
83
67
February
86.2
67
89
77
89
93
March
91.7
85
95
85
95
93
April
90.5
88
74
92
96
May
94.9
99
84
94
99
June
97.2
97
95
99
96
July
97.0
99
97
90
100
August
95.2
91
97
91
95
September
93.2
91
90
99
100
October
87.6
86
85
85
92
November
89.7
90
91
89
92
December
81.9
71
67
83
90
Average
89.2
73.3
89.2
86.7
91.1
93.4
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
-10.5
-9
-10
-13
-6
-8
February
-10.8
-2
-8
-13
-13
-7
March
-1.5
-1
-5
-3
7
1
April
8.4
6
4
11
8
May
19.5
23
17
19
18
June
25.7
28
24
28
26
July
26.9
25
26
30
27
August
26.1
25
26
26
27
September
20.3
23
21
23
20
October
10.2
11
12
15
7
November
-1.7
2
0
2
3
December
-7.8
-1
-8
-8
-3
Average
7.7
-4.2
10.0
8.4
11.3
9.8
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
-18.4
-15
-17
-24
-14
-16
February
-19.5
-9
-19
-24
-21
-17
March
-11.6
-10
-15
-12
-6
-9
April
-3.3
-3
-3
-2
-3
May
5.9
9
7
4
5
June
13.0
15
12
13
13
July
14.5
12
15
16
16
August
12.9
13
14
14
14
September
8.8
11
9
10
7
October
1.2
2
2
4
-2
November
-8.1
-5
-7
-6
-8
December
-15.6
-9
-15
-17
-12
Average
-3.4
-12.3
-1.6
-2.3
-1.6
-2.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
43.5
48
49
42
25
57
February
32.7
27
18
55
26
31
March
15.0
21
14
17
9
14
April
14.9
17
37
13
15
May
9.5
6
19
9
7
June
6.8
6
11
4
4
July
5.4
4
14
2
6
August
5.6
6
7
7
5
September
9.5
11
7
3
6
October
14.9
19
16
14
8
November
23.4
20
28
14
14
December
27.8
18
52
23
21
Average
17.6
31.3
14.5
22.6
11.1
14.0
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
10.4
11
9
11
10
11
February
10.9
10
11
13
11
11
March
11.6
12
11
11
12
13
April
11.9
13
14
12
11
May
11.3
11
12
11
12
June
10.5
8
11
11
12
July
9.3
8
9
9
10
August
9.1
8
9
11
9
September
10.8
9
10
12
12
October
11.3
10
11
11
12
November
11.2
12
11
11
12
December
10.0
10
12
9
9
Average
10.7
11.0
10.1
11.2
10.7
11.2
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
241°
205°
290°
233°
213°
February
319°
219°
298°
249°
251°
March
340°
356°
284°
211°
224°
April
034°
023°
360°
305°
May
093°
172°
331°
179°
June
107°
291°
289°
190°
July
289°
281°
228°
234°
August
277°
257°
269°
259°
September
143°
230°
238°
286°
October
344°
290°
201°
282°
November
270°
243°
236°
221°
December
209°
024°
254°
251°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.