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
68.0
49
62
79
75
81
February
79.7
88
75
70
88
85
March
79.7
77
75
69
95
77
April
88.5
89
88
91
89
May
90.5
94
90
93
90
June
93.4
84
96
97
96
July
93.7
87
97
93
96
August
93.4
91
90
92
95
September
92.7
97
87
95
91
October
88.4
90
93
81
94
November
85.7
93
80
89
88
December
74.5
56
74
82
77
Average
84.9
70.9
83.5
85.2
89.7
88.9
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.