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
85.7
84
85
83
86
89
February
88.1
94
88
91
81
87
March
92.0
90
91
96
95
87
April
88.7
86
94
88
87
May
94.5
93
97
90
99
June
95.2
96
96
96
92
July
95.7
99
98
89
97
August
98.3
100
98
97
100
September
96.4
100
94
96
94
October
93.0
93
97
90
94
November
87.9
88
77
93
86
December
91.4
96
83
88
96
Average
92.3
89.4
93.0
94.5
91.1
92.3
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.