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
72.9
73
63
77
77
75
February
81.8
88
92
83
81
77
March
83.6
75
82
87
95
84
April
90.2
93
92
93
89
May
90.3
95
93
87
92
June
90.7
85
95
94
96
July
93.8
90
95
88
94
August
91.9
94
93
89
93
September
91.5
91
86
95
93
October
85.4
83
95
79
82
November
85.3
89
81
92
91
December
79.8
84
72
83
77
Average
86.1
78.4
87.3
88.6
88.1
87.6
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
2.5
2
6
-1
3
5
February
5.8
8
10
4
0
4
March
9.3
12
8
11
13
11
April
15.5
18
14
16
13
May
21.6
22
22
20
20
June
25.9
25
27
27
27
July
28.2
28
28
27
30
August
27.1
26
28
28
27
September
24.1
24
23
24
23
October
17.6
17
17
20
16
November
9.4
11
11
9
13
December
5.3
8
4
8
4
Average
15.0
7.3
16.7
16.1
16.4
16.1
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
-5.4
-3
0
-9
-4
-2
February
-4.7
-2
-3
-5
-7
-3
March
-1.7
2
-1
0
1
3
April
4.5
5
4
5
3
May
10.2
8
11
9
9
June
14.9
13
15
17
15
July
17.5
17
18
17
18
August
16.5
16
17
18
16
September
13.5
13
13
14
12
October
8.2
9
6
11
8
November
1.0
1
3
0
4
December
-2.8
2
-1
0
-1
Average
5.5
-2.8
6.7
6.1
6.9
6.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
39.6
45
46
42
29
36
February
28.9
18
17
36
33
30
March
22.3
21
32
24
10
17
April
16.6
15
19
12
18
May
12.1
11
10
15
12
June
6.4
8
4
6
2
July
4.4
4
5
6
3
August
4.7
5
2
7
7
September
6.2
4
11
6
3
October
12.5
16
7
12
16
November
21.4
17
25
18
14
December
27.2
30
26
18
30
Average
17.2
27.7
15.9
16.1
13.2
14.3
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
8.7
10
8
9
8
8
February
9.1
9
10
10
9
9
March
9.6
9
10
10
10
9
April
8.9
8
9
9
9
May
7.9
7
8
7
9
June
7.3
7
7
7
7
July
6.5
7
7
7
6
August
6.2
6
6
5
6
September
6.7
6
7
8
7
October
7.6
7
8
7
8
November
8.4
9
9
8
9
December
8.1
8
8
8
9
Average
8.0
9.1
7.6
8.1
7.5
7.8
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
228°
230°
258°
258°
235°
February
257°
240°
238°
268°
255°
March
243°
265°
249°
257°
237°
April
242°
243°
270°
287°
May
334°
163°
301°
226°
June
305°
275°
227°
253°
July
258°
254°
281°
270°
August
276°
239°
244°
262°
September
012°
264°
238°
198°
October
246°
227°
205°
244°
November
233°
222°
229°
236°
December
213°
203°
216°
235°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.