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
93
98
93
100
98
February
97.0
96
99
94
99
98
March
98.2
98
100
97
99
99
April
98.1
96
99
97
99
May
97.3
100
98
100
93
June
96.8
96
96
96
98
July
98.8
98
100
100
98
August
98.2
98
100
98
97
September
98.0
98
97
99
97
October
96.7
97
98
99
94
November
95.7
93
94
94
95
December
97.3
95
95
97
100
Average
97.3
95.9
97.5
96.8
98.1
97.0
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.