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
87.0
86
86
87
85
86
February
82.0
97
89
60
79
87
March
89.9
93
92
80
90
89
April
94.3
89
96
92
100
May
97.2
97
99
96
99
June
97.8
97
100
97
96
July
98.3
95
99
98
99
August
98.1
95
97
100
99
September
98.5
99
99
99
100
October
92.6
95
94
96
95
November
89.5
87
80
99
94
December
89.8
94
71
92
98
Average
93.2
91.7
93.1
89.4
93.5
94.0
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.