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
82.6
72
74
90
91
84
February
86.6
93
82
88
91
84
March
87.7
81
84
78
97
88
April
90.6
84
93
89
96
May
94.0
95
94
97
95
June
92.1
82
90
93
100
July
95.6
94
92
94
99
August
97.4
95
99
97
98
September
96.0
99
92
96
97
October
94.4
95
95
93
98
November
92.4
97
87
92
94
December
83.2
76
79
85
88
Average
90.6
81.5
88.0
90.0
93.2
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.