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
86.0
96
80
84
96
95
February
95.7
98
94
98
99
99
March
94.8
96
98
100
90
95
April
90.2
94
98
95
93
May
86.2
86
96
95
92
June
86.0
95
91
89
88
July
84.5
78
87
87
96
August
83.4
81
86
87
86
September
83.0
85
90
85
72
October
78.4
80
67
84
92
November
74.2
71
63
84
88
December
78.9
74
83
89
79
Average
86.5
96.3
84.3
88.3
91.0
90.2
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.