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
77.4
64
62
89
85
90
February
87.7
88
85
84
92
91
March
85.5
82
78
79
98
87
April
92.6
92
90
92
96
May
88.5
96
60
96
94
June
94.2
86
97
95
100
July
94.6
90
95
95
97
August
95.7
91
97
94
98
September
92.6
87
91
97
93
October
92.6
85
94
90
100
November
93.0
96
91
94
94
December
84.6
59
91
90
90
Average
89.3
77.5
84.0
87.5
93.4
94.1
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.