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
71.1
77
53
67
80
68
February
73.1
64
71
66
80
76
March
73.6
52
74
71
83
77
April
72.5
79
70
70
81
May
76.4
77
76
88
76
June
70.4
44
71
81
74
July
72.1
50
75
68
73
August
77.5
67
71
74
82
September
77.4
69
75
76
74
October
79.7
77
69
85
78
November
76.5
83
80
73
74
December
72.8
66
55
82
72
Average
73.5
63.1
66.2
71.2
78.2
75.6
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.