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
91.6
91
94
81
90
94
February
92.7
100
93
81
94
89
March
94.6
94
94
89
90
93
April
97.3
93
98
98
95
May
98.6
97
97
100
98
June
98.7
97
100
100
100
July
97.3
98
96
99
98
August
97.0
97
93
99
94
September
95.2
91
94
97
97
October
91.1
93
90
89
88
November
89.0
89
94
85
92
December
91.6
93
75
90
97
Average
95.3
95.1
94.5
92.8
95.5
95.0
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
-16.0
-21
-8
-17
-10
-25
February
-15.1
-13
-13
-13
-19
-14
March
-4.7
0
-5
-2
-6
-7
April
5.8
5
4
5
5
May
15.8
17
14
14
17
June
21.3
21
23
23
19
July
23.6
28
23
24
20
August
20.0
23
20
19
19
September
13.3
12
14
12
13
October
2.7
2
4
4
-1
November
-11.2
-6
-9
-10
-14
December
-15.8
-8
-19
-22
-13
Average
1.9
-12.8
5.5
4.2
2.8
1.6
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.