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
94.3
92
92
95
96
96
February
94.2
94
98
89
95
95
March
97.6
94
98
97
99
98
April
98.0
98
96
97
98
May
98.7
97
99
100
100
June
97.9
96
98
97
98
July
98.0
98
97
97
100
August
97.7
96
97
99
99
September
97.3
97
90
98
98
October
99.0
99
99
99
99
November
93.6
90
85
96
96
December
92.9
95
90
87
97
Average
96.5
93.3
96.2
94.8
96.9
97.9
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.