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
83.1
70
72
85
92
92
February
89.8
87
93
84
86
93
March
85.9
82
89
84
97
91
April
93.1
94
94
96
99
96
May
95.8
95
91
98
99
95
June
95.8
97
93
94
99
95
July
93.1
91
92
94
88
96
August
92.8
89
93
99
94
99
September
92.6
90
99
96
100
October
96.7
94
96
98
96
November
87.0
92
79
93
84
December
91.3
97
88
90
94
Average
91.7
88.7
90.9
91.9
94.6
94.5
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
-6.4
-10
-4
-5
-4
-9
February
-6.3
-1
-4
-3
-11
-1
March
0.7
1
-2
3
7
-2
April
9.9
13
12
9
13
7
May
19.4
17
25
17
18
17
June
21.9
20
24
21
25
21
July
24.0
27
23
24
25
23
August
23.7
25
24
26
25
23
September
18.7
20
23
21
19
October
11.0
12
16
12
7
November
0.5
5
-3
3
-1
December
-5.6
2
-10
-11
-2
Average
9.8
11.4
11.5
10.6
10.2
8.5
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
-16.8
-19
-13
-15
-13
-19
February
-17.6
-12
-14
-13
-21
-13
March
-11.3
-10
-14
-8
-5
-14
April
-4.7
-1
-2
-4
-5
-6
May
4.5
5
7
3
4
4
June
8.7
7
10
9
11
9
July
10.5
12
11
11
11
11
August
8.9
10
9
10
9
9
September
4.5
5
5
5
6
October
-3.5
-2
0
-3
-4
November
-10.6
-6
-12
-8
-10
December
-15.8
-9
-22
-20
-11
Average
-3.4
-2.8
-2.6
-3.8
-3.1
-4.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
24.8
30
11
37
21
20
February
27.8
23
30
36
40
18
March
21.9
32
30
27
13
24
April
14.5
13
10
20
8
15
May
11.3
27
4
12
11
13
June
14.4
16
20
19
6
19
July
7.9
8
11
9
5
11
August
7.9
7
12
8
9
5
September
9.9
8
3
5
2
October
9.4
12
5
5
18
November
19.1
2
30
10
15
December
20.4
1
35
35
16
Average
15.1
19.0
12.6
18.5
12.6
14.2
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
7.3
6
7
8
9
8
February
7.4
7
7
9
8
7
March
7.9
8
7
10
8
9
April
9.2
10
9
11
9
10
May
9.6
10
10
10
9
10
June
8.9
10
8
10
8
8
July
6.8
7
7
7
7
8
August
7.0
7
7
7
8
8
September
7.9
8
7
9
9
October
8.8
9
8
9
9
November
7.2
6
9
8
7
December
7.0
6
7
7
7
Average
8.0
8.1
7.5
8.5
8.2
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
114°
241°
299°
224°
200°
February
304°
226°
292°
275°
264°
March
146°
156°
299°
223°
311°
April
309°
156°
330°
297°
285°
May
318°
136°
314°
189°
027°
June
297°
322°
334°
273°
296°
July
274°
296°
258°
142°
282°
August
183°
254°
260°
288°
252°
September
216°
276°
262°
294°
October
251°
263°
185°
284°
November
261°
324°
200°
252°
December
172°
276°
291°
230°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.