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
71.5
58
62
78
81
82
February
82.8
91
82
77
87
82
March
80.7
82
73
69
93
80
April
88.9
86
91
91
94
May
90.6
92
91
94
91
June
93.3
83
96
95
98
July
92.6
86
95
90
96
August
93.7
86
95
94
95
September
92.9
94
89
93
91
October
87.7
91
86
77
96
November
85.8
88
77
89
89
December
73.6
55
76
80
78
Average
86.0
75.7
81.4
85.2
89.2
90.0
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.