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
85.5
78
78
78
90
85
February
91.2
92
91
94
93
89
March
94.0
97
88
95
95
91
April
96.4
92
100
96
96
May
96.6
99
92
92
97
June
99.0
98
100
99
98
July
96.6
98
99
98
96
August
98.2
99
98
98
96
September
97.8
100
97
96
100
October
94.2
95
94
96
93
November
85.6
84
89
85
93
December
85.8
77
84
90
89
Average
94.0
89.7
93.2
94.6
94.7
94.4
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
-13.0
-15
-9
-14
-8
-21
February
-9.3
-8
-9
-4
-12
-9
March
-3.1
0
-4
-1
-6
-5
April
5.2
2
3
6
6
May
13.1
13
11
12
14
June
18.1
19
20
19
16
July
20.6
22
21
21
18
August
18.2
21
18
18
16
September
12.9
12
14
11
13
October
4.3
4
5
3
3
November
-7.2
-2
-7
-13
-8
December
-11.3
-9
-16
-15
-9
Average
2.8
-8.3
5.1
4.8
2.9
2.9
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.