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
94.4
93
94
98
February
95.8
95
96
98
March
92.7
94
90
96
April
97.0
97
95
100
May
96.3
94
97
100
June
99.0
99
99
99
July
98.8
98
100
100
August
98.9
100
98
100
September
100.0
100
100
October
98.1
98
November
98.0
100
95
December
93.3
99
77
97
Average
92.7
94.1
96.1
76.8
97.7
98.8
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
-1.7
-3
-2
5
February
0.0
4
1
-5
March
5.2
5
-1
12
April
12.9
13
14
12
May
20.5
24
18
20
June
26.8
26
30
26
July
31.3
30
34
30
August
31.1
36
30
32
September
24.9
27
24
October
10.9
11
November
8.3
9
8
December
2.7
6
-8
5
Average
8.4
2.1
12.0
-8.0
17.4
18.8
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.