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
85.9
78
77
90
88
88
February
84.8
90
84
89
77
92
March
89.4
87
86
95
96
84
April
91.1
90
88
93
90
83
May
94.2
93
93
96
96
June
96.0
94
98
97
96
July
97.4
100
98
92
99
August
96.2
98
89
95
99
September
95.6
98
96
99
99
October
91.7
97
96
95
90
November
87.0
81
79
96
91
December
76.8
48
61
79
95
Average
90.5
86.4
87.7
90.7
91.9
92.6
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.