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
90.3
84
89
96
93
91
February
86.6
85
91
90
90
95
March
88.4
78
92
97
86
April
92.0
90
90
92
93
May
96.4
97
100
95
97
June
98.0
98
95
99
96
July
97.2
97
97
90
100
August
95.2
97
98
95
99
September
93.5
92
98
99
100
October
90.1
78
91
97
90
November
89.2
100
77
96
90
December
90.1
93
89
89
88
Average
91.7
84.1
91.7
93.0
94.5
94.0
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.