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
73.3
66
76
47
80
77
February
85.8
90
91
87
83
88
March
94.3
91
93
88
97
93
April
96.2
92
96
98
100
May
97.5
97
95
100
96
June
98.3
100
95
100
98
July
98.8
100
95
100
100
August
97.8
98
100
100
99
September
92.5
99
100
92
75
October
88.2
89
97
83
80
November
81.1
89
69
81
88
December
79.7
78
85
89
72
Average
90.5
83.2
92.7
89.1
92.9
89.8
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.