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
98.0
94
99
100
90
99
February
96.9
99
99
99
82
100
March
99.4
99
99
100
99
99
April
99.1
98
100
99
98
May
99.1
98
99
99
99
June
97.8
92
99
99
99
July
98.8
99
98
99
99
August
99.3
99
98
100
99
September
89.8
98
99
35
99
October
98.5
99
100
99
97
November
92.0
98
98
99
97
December
97.3
99
96
97
93
Average
97.2
97.4
98.0
98.8
91.2
98.0
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.