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
77.1
73
63
73
89
89
February
78.1
85
78
79
84
82
March
87.2
87
79
82
95
91
April
91.4
85
91
95
99
May
96.9
98
96
98
99
June
95.4
82
98
100
98
July
96.1
86
98
99
98
August
95.6
92
92
97
96
September
93.6
91
82
100
95
October
92.4
90
97
88
91
November
90.7
91
87
95
96
December
83.1
66
75
93
90
Average
90.0
82.2
83.7
88.3
94.8
94.3
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.