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
80.2
75
67
78
89
89
February
86.0
91
85
83
88
84
March
89.5
87
87
85
98
91
April
92.1
91
91
94
97
98
May
97.3
98
97
98
99
June
97.0
89
99
99
97
July
97.5
93
98
100
98
August
97.7
96
97
98
97
September
96.4
96
92
100
98
October
92.4
91
98
91
93
November
91.0
93
89
96
94
December
84.8
69
81
94
90
Average
91.9
86.1
88.8
91.9
96.1
94.4
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.