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
88.8
83
88
97
91
88
February
85.6
89
91
96
72
92
March
94.4
97
95
100
99
April
96.7
97
98
97
May
96.6
96
98
97
June
97.3
100
100
5
July
99.6
100
100
August
98.6
98
98
September
96.8
100
99
October
91.5
93
97
92
November
87.4
82
78
94
95
December
85.0
87
67
86
97
Average
91.9
88.9
94.1
95.3
90.5
91.3
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.