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
85.6
91
80
76
95
88
February
84.5
85
83
81
86
88
March
83.9
73
80
77
93
92
April
86.8
81
86
93
95
May
91.4
92
93
94
91
June
86.3
74
77
94
88
July
87.1
72
90
87
86
August
88.2
78
84
86
93
September
86.9
72
81
92
90
October
88.2
83
81
92
92
November
90.0
91
86
94
93
December
85.1
84
70
88
86
Average
87.1
81.8
80.1
82.4
91.0
90.2
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.