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
91.9
84
93
99
92
91
February
89.3
97
86
97
81
96
March
92.6
92
91
99
99
92
April
94.2
97
94
91
86
May
95.1
96
97
96
100
June
99.1
99
100
99
100
July
99.3
100
100
98
99
August
98.5
100
98
98
100
September
98.0
100
100
100
98
October
94.6
96
98
95
98
November
88.6
81
82
92
96
December
84.7
78
66
83
96
Average
93.8
91.1
93.3
95.0
94.0
96.0
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.