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
80.2
75
67
78
89
89
February
86.0
91
85
83
88
84
March
89.5
87
87
85
98
91
April
92.1
91
91
94
97
98
May
96.9
95
98
97
98
99
June
96.7
95
89
99
99
97
July
97.1
94
93
98
100
98
August
96.0
85
96
97
98
97
September
96.3
96
96
92
100
98
October
92.4
91
98
91
93
November
91.0
93
89
96
94
December
84.8
69
81
94
90
Average
92.4
90.1
88.8
91.9
96.1
94.4
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
-4.4
-2
-1
-8
-3
-2
February
-2.8
2
-2
-2
-3
-1
March
3.4
6
4
3
6
5
April
11.6
13
14
11
14
10
May
20.1
22
21
22
20
19
June
24.8
26
25
24
27
25
July
27.5
28
27
27
25
29
August
25.8
26
24
26
28
25
September
21.9
23
23
20
22
20
October
15.0
16
16
16
13
November
5.7
6
8
6
9
December
-1.8
2
3
1
1
Average
13.0
15.9
13.2
13.0
13.3
12.9
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
-11.6
-8
-7
-18
-9
-8
February
-10.5
-6
-10
-11
-11
-9
March
-5.8
-1
-3
-5
-4
-3
April
2.5
3
3
2
4
1
May
9.7
12
9
11
10
9
June
15.3
17
15
15
17
15
July
18.5
19
19
18
17
20
August
17.3
17
16
18
20
17
September
13.1
14
14
12
14
11
October
7.1
10
6
9
6
November
-1.0
-1
2
0
1
December
-7.5
-3
-3
-7
-5
Average
4.7
7.6
5.2
4.3
5.0
4.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
39.3
40
47
40
33
33
February
30.1
19
34
37
31
34
March
23.0
24
28
32
10
20
April
22.8
29
19
21
19
17
May
11.3
12
11
11
6
5
June
11.6
17
13
15
9
4
July
7.3
11
12
5
5
6
August
9.7
20
12
10
6
12
September
8.6
6
7
17
7
9
October
16.4
21
8
19
19
November
21.1
15
26
15
13
December
30.4
37
31
22
29
Average
17.9
19.1
20.0
19.7
13.9
15.3
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
9.5
10
9
9
8
9
February
10.5
9
10
12
9
11
March
10.8
11
11
11
11
11
April
10.9
11
11
11
10
12
May
9.4
9
10
9
9
10
June
9.2
9
8
10
10
10
July
8.5
9
8
10
8
9
August
8.2
8
8
8
9
8
September
8.0
8
8
8
8
9
October
9.0
8
8
8
9
November
9.6
10
9
9
10
December
9.4
8
11
10
10
Average
9.4
9.2
8.9
9.5
9.1
9.6
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
300°
326°
336°
275°
287°
February
241°
292°
263°
258°
257°
March
293°
277°
271°
252°
257°
April
098°
238°
294°
328°
298°
May
187°
261°
189°
254°
261°
June
242°
041°
229°
221°
231°
July
248°
223°
237°
242°
224°
August
222°
234°
255°
223°
244°
September
217°
248°
293°
230°
223°
October
224°
196°
033°
228°
November
240°
229°
253°
240°
December
001°
330°
273°
246°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.