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
74.9
56
68
78
86
79
February
81.7
88
83
84
79
81
March
82.8
81
74
76
97
79
April
86.2
78
85
94
89
94
May
89.2
95
90
93
91
June
93.5
84
96
94
97
July
93.7
87
99
88
99
August
95.5
92
95
96
96
September
92.5
94
88
93
95
October
86.7
92
91
71
96
November
88.2
91
85
89
89
December
75.9
64
75
79
84
Average
86.3
75.9
84.8
88.4
88.4
90.4
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.