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
82.0
80
91
65
93
85
February
84.7
77
92
87
85
91
March
94.7
95
98
85
99
97
April
97.0
96
99
99
100
May
97.0
97
97
97
95
June
97.4
100
95
100
96
July
98.3
100
96
100
99
August
95.9
95
100
96
94
September
89.0
97
96
90
75
October
89.9
84
98
88
85
November
82.1
81
74
89
94
December
80.9
72
69
93
83
Average
90.9
84.6
92.6
90.1
94.4
91.5
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.