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
85.0
80
81
88
83
88
February
78.7
82
88
81
74
82
March
85.4
83
88
92
93
80
April
87.5
75
90
93
75
May
90.0
88
90
88
94
June
91.6
93
92
89
92
July
91.1
94
94
87
91
August
93.8
97
89
92
93
September
94.2
96
94
94
94
October
91.2
91
93
93
85
November
78.2
73
65
92
85
December
78.5
84
69
82
95
Average
87.0
81.6
88.3
87.6
88.4
87.7
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.