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
77.0
68
65
73
86
86
February
85.1
90
91
78
84
79
March
87.2
79
88
96
86
April
92.2
96
92
95
89
May
92.2
96
91
95
92
June
94.9
87
98
99
99
July
97.0
94
97
95
99
August
97.4
93
97
98
99
September
96.6
100
94
96
93
October
94.6
94
98
96
93
November
93.4
93
88
96
97
December
86.2
83
85
89
84
Average
90.1
78.5
89.4
90.4
94.0
91.9
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
2.9
2
6
-1
2
6
February
5.9
8
10
4
0
4
March
9.1
8
11
13
11
April
15.3
17
13
16
14
May
21.5
21
23
21
20
June
26.2
25
27
27
26
July
28.7
28
30
27
30
August
27.6
26
29
28
27
September
24.8
24
23
25
23
October
18.3
18
18
20
16
November
10.1
11
12
10
13
December
5.9
9
5
9
4
Average
15.0
5.0
16.7
16.6
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
-4.5
-3
0
-8
-3
-1
February
-3.4
-1
-1
-5
-7
-2
March
0.4
1
1
2
3
April
5.5
6
5
6
4
May
11.4
10
13
10
10
June
16.9
15
17
18
17
July
19.5
19
19
19
20
August
18.4
18
18
19
18
September
15.7
16
15
16
13
October
9.8
10
8
12
8
November
2.4
3
4
2
5
December
-1.7
3
0
1
-1
Average
6.6
-2.0
8.1
7.6
8.0
7.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
32.4
44
44
41
25
23
February
21.9
12
16
39
30
20
March
17.0
33
24
8
11
April
12.7
14
20
10
12
May
9.6
8
12
9
11
June
4.6
6
3
6
2
July
3.4
6
4
5
1
August
3.7
7
3
4
4
September
5.0
3
12
5
3
October
8.2
7
8
7
13
November
14.0
15
23
11
15
December
17.8
23
24
11
19
Average
13.7
28.8
14.4
16.7
9.9
10.2
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
9.8
10
8
10
8
10
February
10.5
10
11
11
11
10
March
10.7
11
11
11
10
April
9.8
9
10
9
10
May
8.9
8
9
8
9
June
8.4
8
8
8
9
July
7.5
7
8
8
8
August
7.4
7
7
7
7
September
8.0
7
8
9
8
October
8.9
9
10
8
9
November
9.7
10
10
9
11
December
9.1
8
9
10
10
Average
9.1
9.9
8.5
9.3
8.7
9.0
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
234°
241°
274°
254°
230°
February
260°
237°
240°
268°
260°
March
264°
246°
275°
264°
April
255°
253°
263°
285°
May
354°
179°
342°
291°
June
329°
282°
229°
302°
July
271°
260°
286°
288°
August
293°
257°
270°
279°
September
344°
272°
260°
205°
October
253°
221°
215°
233°
November
238°
225°
229°
233°
December
221°
218°
216°
235°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.