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
85.6
84
77
81
92
88
February
90.0
78
86
96
94
96
March
97.0
98
100
91
100
98
April
99.3
99
100
99
100
May
99.2
97
100
100
100
June
99.7
100
99
100
100
July
97.4
99
100
87
100
August
88.8
87
97
81
99
September
94.1
92
94
100
79
October
98.0
100
100
98
96
November
94.3
99
83
96
96
December
89.4
84
77
90
89
Average
94.0
86.3
93.4
93.9
94.7
95.4
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.