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
83.7
70
81
74
96
91
February
87.0
81
86
82
90
91
March
92.0
80
88
94
96
97
April
96.3
96
95
96
97
98
May
98.8
99
97
100
100
June
99.6
100
99
100
99
July
99.8
100
100
100
100
August
99.0
99
100
98
98
September
99.2
100
100
100
98
October
97.2
96
97
92
100
November
93.2
90
79
98
95
December
82.3
72
82
88
90
Average
93.3
81.5
92.7
92.6
96.5
96.7
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
0.9
2
-1
-2
3
3
February
3.0
6
0
1
3
4
March
9.2
8
3
11
11
11
April
14.7
16
13
13
16
15
May
20.7
22
18
22
21
June
26.7
24
26
32
25
July
33.1
33
34
34
32
August
31.4
30
33
30
33
September
25.7
24
29
26
27
October
15.7
17
18
16
18
November
8.0
8
3
11
8
December
1.7
3
0
4
3
Average
15.0
7.8
14.8
15.8
17.2
16.6
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
-7.0
-6
-7
-10
-6
-4
February
-7.9
-2
-11
-11
-4
-8
March
-3.6
-3
-5
-2
-4
-1
April
1.0
2
0
-1
0
1
May
5.4
7
4
5
6
June
9.3
8
9
12
9
July
12.8
13
13
14
11
August
11.7
13
13
10
13
September
7.2
8
9
7
6
October
0.7
3
1
3
2
November
-4.5
-4
-6
-1
-4
December
-7.4
-6
-9
-4
-8
Average
1.4
-3.5
1.5
1.2
2.7
1.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.4
31
16
4
4
9
February
14.2
19
15
5
13
7
March
10.9
22
15
6
5
9
April
8.5
6
8
12
8
6
May
5.3
3
9
4
5
June
2.5
2
2
0
10
July
0.8
1
1
1
1
August
2.1
6
2
3
1
September
2.8
6
1
2
0
October
6.1
7
6
11
1
November
7.4
9
12
4
10
December
10.9
15
13
14
5
Average
8.0
19.4
8.0
5.6
5.4
5.2
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
8.5
9
8
8
9
11
February
11.1
10
8
8
15
10
March
10.2
10
11
11
9
11
April
11.4
12
10
11
11
11
May
9.4
7
12
10
10
June
9.6
7
11
10
10
July
7.8
8
8
8
9
August
8.0
8
7
8
9
September
8.1
7
8
9
8
October
9.2
7
8
9
12
November
8.3
7
9
9
9
December
8.7
8
9
13
8
Average
9.3
10.1
8.0
9.1
9.7
9.8
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
227°
258°
249°
213°
230°
February
223°
240°
254°
237°
250°
March
235°
231°
235°
246°
235°
April
238°
245°
243°
267°
247°
May
230°
241°
253°
247°
June
266°
243°
266°
237°
July
270°
267°
262°
262°
August
253°
276°
251°
254°
September
248°
239°
244°
259°
October
243°
249°
223°
246°
November
226°
223°
233°
219°
December
230°
212°
215°
231°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.