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
98.6
98
99
100
98
100
February
99.1
100
100
100
100
97
March
99.3
100
100
100
100
98
April
98.7
100
100
100
100
May
99.1
99
100
100
100
June
99.3
100
100
100
100
July
92.7
100
97
100
100
August
97.4
100
99
100
100
September
98.8
99
100
99
100
October
98.9
99
99
99
100
November
98.0
99
96
100
99
December
97.3
98
97
98
100
Average
98.2
99.0
99.4
99.0
99.5
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.