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
85.9
70
80
91
92
92
February
84.7
72
89
90
87
96
March
86.7
89
71
91
96
93
April
93.9
94
90
92
97
98
May
95.8
88
99
93
99
June
98.2
96
96
99
100
July
98.9
94
100
100
100
August
97.7
95
100
96
99
September
94.4
86
100
99
99
October
86.9
90
62
97
77
November
90.8
94
87
99
89
December
89.5
98
67
91
92
Average
91.5
81.7
88.9
90.8
95.6
94.9
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
-2.7
-4
-2
1
4
-2
February
-3.2
1
0
2
-6
4
March
4.8
5
-2
10
12
5
April
13.1
16
12
11
15
12
May
20.9
24
20
18
20
June
26.1
26
25
30
25
July
31.8
31
32
34
30
August
30.5
31
33
29
32
September
23.7
25
28
26
24
October
13.8
13
18
18
11
November
5.3
9
0
10
7
December
0.6
7
-8
-4
4
Average
12.8
4.4
14.4
15.0
15.5
14.3
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
-12.2
-16
-11
-11
-7
-10
February
-14.8
-9
-9
-10
-17
-7
March
-8.8
-6
-12
-4
-3
-6
April
-1.4
1
0
-3
0
-2
May
5.7
9
5
4
5
June
10.3
11
10
11
11
July
13.1
13
14
15
12
August
12.2
13
14
13
12
September
7.6
8
10
8
8
October
-1.9
1
3
1
-2
November
-6.5
-3
-9
-3
-4
December
-10.1
-5
-20
-15
-5
Average
-1.2
-8.6
1.2
0.4
0.5
0.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.8
14
10
8
1
6
February
10.7
8
7
5
9
4
March
5.6
8
13
3
2
5
April
6.3
5
12
7
5
4
May
6.0
8
4
9
5
June
5.9
8
10
2
7
July
1.0
1
2
1
2
August
1.7
1
1
5
0
September
5.9
7
2
1
7
October
6.3
13
9
2
9
November
7.6
3
15
2
5
December
9.5
2
34
8
2
Average
6.2
8.7
7.1
7.1
3.8
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
10.1
9
10
12
12
10
February
10.4
8
12
12
11
12
March
10.0
9
10
12
11
11
April
10.8
11
10
11
11
11
May
9.6
9
12
9
10
June
10.0
8
11
10
10
July
8.1
8
7
8
9
August
8.4
8
9
10
9
September
8.8
8
9
10
10
October
10.2
8
10
10
9
November
10.7
9
13
11
12
December
10.0
8
9
9
11
Average
9.7
9.4
8.8
10.6
9.9
10.2
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
260°
243°
250°
247°
255°
February
248°
242°
259°
244°
255°
March
050°
072°
277°
253°
269°
April
285°
306°
295°
277°
280°
May
103°
258°
285°
215°
June
241°
259°
268°
259°
July
271°
311°
305°
252°
August
267°
280°
276°
254°
September
270°
285°
258°
276°
October
268°
257°
263°
254°
November
238°
257°
249°
247°
December
240°
269°
248°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.