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
78.9
63
77
92
83
82
February
87.1
93
89
87
90
88
March
90.3
95
87
92
99
84
April
91.8
92
92
95
92
May
94.7
100
97
96
93
June
95.0
87
97
95
99
July
96.0
96
93
91
99
August
97.4
97
98
99
99
September
94.3
95
95
95
95
October
92.4
96
96
82
96
November
90.6
93
93
90
91
December
86.2
76
95
86
87
Average
90.9
84.4
91.1
94.0
92.3
92.7
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
1.0
0
3
-1
1
3
February
3.4
7
6
2
-1
2
March
7.3
10
6
9
11
8
April
12.8
15
12
15
11
May
19.5
19
21
20
18
June
25.1
24
26
26
26
July
27.6
27
28
27
29
August
26.5
25
27
28
27
September
23.0
23
23
24
22
October
16.2
16
17
18
15
November
8.0
10
10
8
11
December
4.2
7
4
7
4
Average
13.5
5.6
15.0
15.2
15.3
14.7
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
-4
-1
-8
-3
-2
February
-5.9
-2
-3
-6
-8
-4
March
-1.5
2
0
0
0
1
April
4.0
5
3
5
3
May
10.3
9
12
9
9
June
16.2
14
16
18
16
July
19.1
19
19
19
20
August
18.3
17
18
19
18
September
15.3
15
15
15
13
October
8.9
9
7
12
7
November
1.7
1
3
1
3
December
-1.0
2
-1
1
-2
Average
6.0
-2.5
7.4
6.8
7.4
7.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.3
24
12
9
7
14
February
10.6
2
9
16
13
10
March
8.8
8
14
8
2
5
April
9.4
12
8
11
8
May
7.6
5
9
8
9
June
4.1
5
2
7
1
July
4.6
6
4
8
3
August
3.5
2
3
4
4
September
4.2
1
3
6
2
October
8.7
9
5
15
7
November
8.9
7
8
9
10
December
10.9
17
4
7
13
Average
8.0
10.6
7.9
6.3
7.7
6.5
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
7.6
8
6
9
7
7
February
8.0
7
9
9
8
8
March
8.3
8
9
8
9
8
April
7.6
7
8
7
8
May
6.6
6
7
6
7
June
6.4
6
6
6
6
July
5.7
5
7
6
5
August
5.9
6
6
6
6
September
6.2
5
7
7
7
October
7.0
7
7
6
7
November
7.6
8
8
8
8
December
7.1
6
8
8
7
Average
7.1
7.7
6.6
7.3
6.8
6.9
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
257°
263°
269°
293°
247°
February
249°
247°
252°
288°
288°
March
261°
288°
272°
246°
258°
April
230°
241°
259°
270°
May
154°
149°
198°
333°
June
082°
232°
207°
211°
July
207°
237°
301°
213°
August
245°
203°
194°
236°
September
171°
264°
232°
203°
October
270°
232°
228°
252°
November
247°
228°
237°
239°
December
249°
260°
236°
259°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.