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
84.7
71
85
64
97
85
February
89.3
92
92
84
85
85
March
96.1
96
97
89
99
96
April
98.8
98
100
100
99
May
98.7
99
99
97
98
June
98.7
97
99
100
98
July
98.7
99
97
99
98
August
97.2
94
98
97
99
September
92.8
100
95
93
72
October
91.8
91
90
95
81
November
91.4
87
87
90
95
December
86.5
78
86
93
92
Average
93.6
86.7
93.6
91.8
95.8
92.1
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.