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
97.4
89
99
99
100
100
February
98.0
98
99
98
100
99
March
98.7
97
97
100
100
98
April
99.5
100
100
100
100
May
98.3
93
100
100
100
June
98.5
93
99
100
100
July
99.4
98
100
99
100
August
98.3
94
99
99
99
September
99.3
97
100
100
100
October
97.7
90
99
100
100
November
97.8
94
98
99
99
December
92.8
70
89
98
99
Average
97.8
94.7
93.6
98.6
99.4
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.