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
99.6
100
99
100
98
99
February
97.0
90
100
99
100
97
March
99.7
99
100
100
100
99
April
99.9
100
100
100
100
May
100.0
100
100
100
100
June
99.9
100
100
100
100
July
99.9
100
100
100
100
August
100.0
100
100
100
100
September
100.0
100
100
100
100
October
99.6
100
100
100
100
November
99.7
100
99
100
100
December
99.5
100
99
100
98
Average
99.3
96.6
99.8
99.7
99.8
99.4
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.