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
99.1
99
97
100
99
100
February
98.9
100
99
98
100
100
March
99.6
100
100
100
100
98
April
99.7
99
100
100
100
May
99.8
100
100
100
100
June
99.7
100
100
100
100
July
99.3
100
98
100
100
August
99.0
99
99
100
100
September
99.0
100
99
99
100
October
99.6
99
100
99
100
November
98.5
98
98
98
98
December
98.3
99
96
99
99
Average
99.3
99.6
99.1
99.0
99.5
99.5
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.