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
81.3
74
62
87
94
89
February
82.5
63
78
93
88
90
March
83.0
72
73
81
92
84
April
90.6
76
92
96
97
May
95.5
99
90
96
98
June
97.6
95
97
100
94
July
98.5
100
100
99
92
August
98.6
98
97
96
100
September
96.4
95
98
92
98
October
95.6
96
94
96
94
November
89.5
92
74
97
94
December
87.3
86
78
87
96
Average
89.5
69.5
87.2
90.3
94.4
93.8
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
0
-5
-2
1
-2
February
-1.1
2
-3
-2
-1
-2
March
3.7
3
-2
6
5
5
April
9.9
5
11
11
11
May
16.6
18
15
17
18
June
23.0
20
24
27
21
July
29.1
28
30
30
28
August
27.3
26
27
26
30
September
22.4
22
25
23
23
October
12.8
15
14
12
16
November
6.0
8
0
9
6
December
0.4
4
-2
2
1
Average
11.2
1.8
11.2
12.8
13.6
13.0
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
-9.2
-7
-10
-10
-8
-8
February
-9.0
-7
-11
-11
-9
-11
March
-5.0
-4
-10
-4
-5
-4
April
-2.5
-4
-2
-2
-2
May
3.7
5
2
4
4
June
8.5
8
9
12
7
July
13.6
14
14
15
12
August
12.2
12
13
12
14
September
7.8
8
10
8
7
October
0.5
2
1
2
2
November
-4.2
-2
-8
-1
-4
December
-8.1
-5
-10
-7
-9
Average
0.0
-6.0
0.5
0.8
1.6
0.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
16.7
26
31
11
7
13
February
15.8
32
23
6
16
8
March
17.0
32
24
18
8
15
April
9.5
24
6
6
3
May
5.3
3
9
3
3
June
2.7
6
4
0
4
July
1.1
1
1
1
1
August
1.7
4
4
1
0
September
3.5
7
2
1
2
October
4.8
7
6
6
2
November
9.2
9
19
2
8
December
12.4
9
28
19
6
Average
10.2
30.1
12.6
8.9
5.5
5.1
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
9.5
9
10
9
10
11
February
11.3
9
11
11
13
10
March
9.9
11
11
10
9
10
April
11.3
9
12
12
12
May
10.1
9
12
11
11
June
10.1
8
10
10
11
July
8.9
10
10
7
11
August
9.1
8
7
10
10
September
9.8
9
9
9
11
October
10.3
9
9
10
13
November
10.0
9
9
11
10
December
9.2
9
9
13
9
Average
10.0
9.9
9.3
9.7
10.3
10.6
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
235°
217°
235°
238°
239°
February
235°
224°
239°
246°
244°
March
231°
227°
251°
244°
235°
April
240°
246°
256°
252°
May
223°
249°
252°
241°
June
227°
232°
238°
243°
July
237°
231°
252°
251°
August
241°
244°
242°
248°
September
232°
244°
246°
255°
October
241°
259°
227°
247°
November
236°
236°
240°
239°
December
230°
238°
231°
245°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.