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
76.1
68
69
80
77
65
February
83.5
79
79
80
81
89
March
84.6
90
67
96
92
91
April
89.6
84
84
96
96
May
95.6
91
95
97
96
June
97.6
94
98
100
100
July
96.3
95
96
90
99
August
93.8
88
91
97
98
September
91.8
83
98
97
97
October
93.1
90
99
94
92
November
91.0
98
77
98
97
December
78.9
75
46
87
87
Average
89.0
79.3
84.8
88.7
92.8
93.0
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
-5.9
-5
-5
-4
1
-4
February
-3.5
6
-3
-2
-5
-1
March
4.6
7
-2
6
12
7
April
11.9
9
10
15
14
May
22.2
26
21
23
20
June
29.4
30
29
32
29
July
30.1
29
30
31
31
August
28.2
29
29
30
30
September
24.4
26
26
26
23
October
14.4
16
18
18
11
November
6.3
9
4
9
11
December
0.0
5
-4
-1
3
Average
12.4
2.7
14.1
14.2
15.9
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
-14.1
-13
-14
-17
-8
-13
February
-14.1
-5
-15
-16
-16
-12
March
-7.6
-6
-13
-6
-2
-3
April
-1.3
-2
-1
0
-1
May
8.1
10
8
7
8
June
15.0
17
15
15
17
July
16.7
14
18
17
18
August
15.1
16
16
16
17
September
10.7
12
11
12
9
October
1.8
3
2
5
0
November
-6.5
-4
-6
-3
-4
December
-11.4
-6
-13
-12
-9
Average
0.2
-8.1
1.6
1.4
2.7
2.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
9.8
8
11
18
9
6
February
10.7
9
16
20
4
4
March
8.7
12
19
1
4
2
April
10.6
15
19
9
5
May
6.6
8
5
8
6
June
3.0
5
1
2
4
July
2.3
2
2
3
2
August
3.4
6
5
2
1
September
5.8
7
1
7
9
October
8.1
8
2
12
7
November
6.7
1
15
5
2
December
10.9
11
35
12
7
Average
7.2
9.9
9.0
8.8
6.1
4.3
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
9.7
8
9
12
10
10
February
10.4
9
11
13
9
10
March
11.3
12
12
13
11
11
April
12.3
13
16
12
11
May
10.5
11
10
11
11
June
9.5
8
10
9
11
July
8.5
8
9
8
9
August
8.4
8
9
9
9
September
9.3
7
9
9
10
October
10.9
11
10
11
11
November
9.9
9
11
10
10
December
10.2
9
13
9
10
Average
10.0
9.7
9.6
11.2
9.8
10.3
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
270°
305°
323°
309°
243°
February
299°
007°
328°
267°
291°
March
357°
010°
348°
205°
347°
April
346°
346°
351°
325°
May
116°
276°
168°
038°
June
084°
236°
170°
162°
July
340°
263°
136°
176°
August
038°
071°
155°
140°
September
050°
174°
205°
303°
October
331°
284°
352°
288°
November
291°
299°
274°
227°
December
313°
335°
315°
302°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.