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
95.9
94
89
93
99
99
February
96.8
96
95
90
99
99
March
99.6
100
100
100
100
100
April
98.8
99
97
100
100
May
98.7
99
97
100
99
June
97.4
100
87
100
99
July
98.1
99
92
98
100
August
98.9
100
96
99
100
September
95.3
99
80
99
98
October
97.8
98
90
99
99
November
97.1
98
88
99
97
December
98.0
95
98
100
99
Average
97.7
96.8
97.7
92.0
99.2
99.0
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.