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
86.4
87
83
69
89
88
February
87.1
96
87
91
87
78
March
95.2
96
99
92
97
97
April
97.2
96
96
99
99
98
May
97.2
100
97
96
96
June
98.2
96
99
98
98
July
98.5
100
98
99
96
August
94.1
97
99
94
99
September
90.9
96
92
92
75
October
89.6
86
84
94
83
November
93.0
98
89
88
93
December
86.0
80
80
84
90
Average
93.3
93.9
93.5
92.0
93.6
91.2
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.