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
86.2
86
86
81
85
94
February
83.2
91
94
82
73
88
March
90.1
85
93
87
94
91
April
91.9
85
94
93
87
May
96.4
96
95
95
98
June
98.1
99
99
98
99
July
98.4
99
100
95
99
August
99.4
99
99
100
100
September
97.7
99
98
98
98
October
94.5
96
98
97
91
November
83.3
72
67
96
96
December
87.3
92
78
91
96
Average
91.9
86.9
92.5
90.4
93.3
94.7
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.