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
92.8
93
97
89
95
97
February
94.0
94
95
94
93
95
March
96.7
96
98
96
94
98
April
97.6
97
97
96
97
May
96.2
99
100
100
94
June
97.8
99
97
99
99
July
98.0
96
98
98
98
August
98.5
99
99
100
98
September
98.4
98
97
99
98
October
97.4
95
100
97
98
November
93.3
94
87
96
97
December
92.8
93
95
89
96
Average
96.1
94.2
96.7
95.9
96.6
97.1
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.