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
83.3
74
80
88
91
83
February
85.4
92
88
89
90
83
March
88.2
91
86
81
97
85
April
90.3
91
94
92
96
May
92.9
96
96
98
97
June
94.5
90
95
98
100
July
96.7
95
95
98
100
August
96.3
97
96
95
95
September
96.4
99
98
95
97
October
92.9
94
97
92
89
November
89.7
93
84
90
91
December
81.8
66
83
87
86
Average
90.7
86.2
90.1
91.9
94.0
92.7
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.