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
87.4
85
87
89
84
89
February
83.7
93
93
82
82
86
March
90.3
89
92
93
94
88
April
90.8
79
95
92
85
May
90.6
82
97
94
97
June
95.4
96
97
95
July
96.2
99
99
91
92
August
98.3
97
97
98
98
September
95.6
99
97
95
94
October
91.4
96
96
94
89
November
84.5
85
70
94
84
December
86.6
89
80
86
97
Average
90.8
88.8
91.1
91.7
91.8
90.4
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.