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
73.7
63
66
93
73
64
February
87.8
93
90
97
76
94
March
86.3
93
87
93
86
79
April
91.4
92
96
94
97
82
May
89.3
94
91
87
100
June
95.8
94
97
96
96
July
97.0
98
95
96
96
August
94.9
94
95
99
99
September
93.4
94
95
97
89
October
91.1
94
100
89
91
November
90.4
98
88
99
88
December
83.5
77
66
89
84
Average
89.6
86.0
90.5
93.4
91.4
88.8
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
-1.2
-2
1
-1
1
-1
February
3.6
11
5
2
2
2
March
9.6
14
9
10
13
11
April
16.5
19
19
15
18
15
May
23.2
26
24
22
23
June
28.6
29
30
30
28
July
29.4
29
30
29
31
August
28.3
29
30
30
31
September
26.2
28
27
28
26
October
17.3
19
19
20
17
November
9.4
11
10
11
15
December
4.7
7
4
8
5
Average
15.6
10.5
17.7
17.1
18.2
16.5
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
-9.6
-8
-6
-13
-5
-8
February
-7.4
-2
-5
-10
-5
-7
March
-1.7
2
-1
0
3
1
April
4.5
7
5
3
6
4
May
12.0
13
13
12
13
June
17.4
18
18
19
18
July
19.1
18
20
20
20
August
17.6
19
19
19
19
September
14.6
15
14
15
14
October
6.9
9
6
10
6
November
-1.5
1
0
1
4
December
-4.1
1
-3
-2
-4
Average
5.3
-1.9
7.1
6.0
8.2
6.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.4
15
8
6
9
19
February
8.7
1
11
7
8
6
March
9.4
6
9
12
10
10
April
8.6
11
4
13
5
9
May
6.8
2
6
11
4
June
4.9
5
4
5
8
July
2.2
3
2
2
4
August
3.4
4
4
1
1
September
6.6
4
5
2
12
October
7.3
5
1
11
5
November
6.6
2
17
3
8
December
9.7
13
20
3
8
Average
7.0
8.0
5.4
7.0
5.6
7.7
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
9.6
9
8
10
9
9
February
9.7
10
9
12
8
10
March
10.8
12
9
12
11
10
April
12.0
13
13
14
11
10
May
9.4
8
11
10
9
June
8.0
7
8
7
9
July
6.1
6
6
6
6
August
6.0
6
5
7
7
September
7.2
7
7
8
8
October
9.3
10
8
9
10
November
10.5
9
12
11
12
December
9.3
9
10
10
8
Average
9.1
11.3
8.3
9.4
8.8
8.7
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
288°
291°
275°
336°
280°
February
257°
272°
293°
223°
316°
March
330°
288°
313°
146°
262°
April
274°
254°
242°
259°
137°
May
116°
163°
167°
351°
June
065°
207°
211°
167°
July
289°
215°
141°
170°
August
189°
204°
162°
189°
September
171°
215°
178°
216°
October
288°
254°
350°
274°
November
240°
247°
246°
220°
December
262°
205°
216°
277°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.