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
79.2
69
79
94
83
68
February
88.6
95
93
97
82
95
March
87.1
95
86
95
89
81
April
91.5
97
87
96
93
May
90.2
93
91
87
91
June
94.4
94
98
99
95
July
97.7
98
97
98
98
August
96.5
96
97
99
98
September
94.3
92
97
98
91
October
90.7
97
98
88
91
November
91.2
98
90
95
90
December
86.7
84
71
90
84
Average
90.5
86.7
92.5
93.5
92.4
90.0
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
-1.6
-2
1
-1
1
0
February
2.9
11
6
3
-5
3
March
9.9
14
8
10
13
12
April
16.1
18
14
17
16
May
22.5
25
23
20
20
June
28.8
29
29
30
29
July
29.9
29
31
30
30
August
28.5
29
30
30
29
September
26.0
27
26
27
24
October
16.7
18
18
19
15
November
9.6
12
9
11
13
December
4.5
7
3
8
3
Average
15.1
7.4
17.4
16.6
16.7
16.2
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
-9.1
-9
-7
-13
-7
-8
February
-8.1
-3
-6
-10
-13
-7
March
-1.3
1
-2
-1
2
2
April
4.0
4
2
6
4
May
10.8
11
11
9
11
June
16.8
16
16
18
18
July
19.0
17
19
19
20
August
17.2
18
18
19
17
September
13.8
14
13
13
12
October
5.7
8
4
8
4
November
-2.9
-1
-1
0
1
December
-5.2
-1
-6
-3
-6
Average
4.2
-4.4
6.0
4.8
5.8
5.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.6
14
7
4
6
8
February
6.4
1
9
8
11
2
March
6.4
4
10
8
4
5
April
4.7
5
5
3
5
May
3.7
1
4
3
4
June
3.2
3
3
4
4
July
1.7
2
2
1
2
August
2.0
3
2
1
1
September
4.4
3
4
1
6
October
4.1
2
2
8
2
November
3.4
1
10
2
5
December
5.1
4
15
1
5
Average
4.5
6.2
4.0
4.7
3.5
4.0
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
8.0
8
9
9
8
9
February
9.1
9
10
10
8
9
March
9.8
10
10
11
11
9
April
10.2
12
11
10
10
May
7.7
8
9
8
8
June
7.3
6
7
6
9
July
6.2
6
7
6
6
August
6.2
7
6
7
7
September
7.0
7
7
7
8
October
8.2
9
8
8
9
November
8.4
8
11
10
10
December
8.5
8
9
10
8
Average
8.1
9.3
8.0
8.7
8.0
8.4
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
296°
294°
288°
329°
287°
February
266°
269°
305°
332°
318°
March
319°
314°
321°
174°
270°
April
259°
254°
266°
289°
May
129°
196°
183°
359°
June
110°
214°
204°
174°
July
314°
241°
217°
171°
August
228°
240°
170°
183°
September
183°
235°
205°
242°
October
296°
273°
313°
295°
November
245°
265°
257°
234°
December
272°
206°
236°
283°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.