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
69.7
55
70
49
72
69
February
82.4
80
85
85
80
89
March
91.7
91
95
75
99
97
April
92.9
92
91
99
96
May
95.2
97
88
99
95
June
95.5
98
92
99
93
July
97.6
99
94
100
97
August
96.9
95
100
99
98
September
89.8
98
98
88
71
October
86.1
83
96
83
83
November
81.8
86
77
74
85
December
76.7
68
84
81
77
Average
87.7
76.1
89.8
86.7
90.6
88.4
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.