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
66.7
53
56
68
69
77
February
79.0
84
77
65
77
79
March
83.3
79
79
77
94
89
April
88.6
97
86
84
91
May
90.5
90
85
95
92
June
91.8
83
90
96
98
July
93.2
88
95
88
93
August
95.0
90
92
97
96
September
92.0
90
84
97
91
October
87.0
81
97
82
85
November
86.2
88
76
88
96
December
74.3
60
66
82
72
Average
85.2
71.1
81.9
82.6
88.6
89.2
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
-2.4
-1
1
-4
-3
1
February
1.1
4
2
0
-2
0
March
4.6
8
3
6
7
7
April
12.0
15
13
13
10
May
19.1
19
22
19
18
June
23.7
24
23
26
25
July
26.6
27
26
25
29
August
25.6
24
27
27
26
September
21.8
22
21
21
21
October
15.7
16
17
17
14
November
6.7
7
9
7
11
December
1.6
5
1
4
2
Average
11.9
3.5
13.8
13.7
13.5
13.5
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
-10.6
-6
-6
-16
-8
-7
February
-8.3
-5
-8
-10
-10
-8
March
-4.1
-1
-4
-4
-4
-1
April
2.3
4
2
3
1
May
8.3
6
10
8
7
June
13.4
13
13
14
14
July
17.1
17
17
15
19
August
15.5
14
14
18
16
September
11.6
12
12
12
10
October
6.7
8
5
9
5
November
-1.2
0
1
-1
2
December
-6.5
-1
-4
-4
-5
Average
3.0
-4.0
4.7
3.5
4.8
4.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
32.2
50
40
29
17
24
February
27.9
19
36
44
32
23
March
23.1
27
34
31
8
14
April
18.5
17
24
18
15
May
12.5
16
15
7
10
June
8.9
13
9
8
1
July
7.0
13
8
9
3
August
6.7
11
10
5
6
September
7.5
3
18
9
6
October
16.4
24
13
15
16
November
19.8
20
24
20
12
December
27.0
35
41
16
22
Average
17.7
32.9
21.4
20.9
12.4
11.5
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
7.9
9
7
8
6
7
February
9.6
9
10
12
8
9
March
9.3
9
10
9
10
10
April
9.5
10
10
9
10
May
7.9
8
8
8
8
June
7.7
7
8
9
8
July
7.1
7
8
7
7
August
6.7
7
7
6
7
September
6.8
6
7
7
8
October
7.9
7
8
7
9
November
8.4
9
9
7
10
December
7.8
7
8
8
9
Average
8.1
9.0
7.7
8.3
7.8
8.3
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
223°
250°
229°
304°
227°
February
221°
217°
230°
219°
245°
March
232°
252°
232°
228°
191°
April
226°
233°
273°
250°
May
285°
228°
261°
254°
June
040°
228°
233°
237°
July
237°
240°
003°
237°
August
238°
232°
218°
239°
September
262°
268°
211°
206°
October
238°
199°
166°
215°
November
222°
229°
220°
219°
December
192°
234°
207°
210°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.