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
91.9
90
94
89
93
93
February
90.3
89
92
82
93
90
March
94.4
90
92
93
94
97
April
95.7
98
95
94
95
95
May
96.0
92
94
98
98
June
95.2
92
95
97
98
July
94.8
94
94
94
96
August
96.9
97
95
97
99
September
95.5
93
89
98
96
October
95.5
95
94
98
94
November
89.5
84
81
93
95
December
90.1
90
88
85
96
Average
93.9
91.9
92.6
91.1
94.9
95.7
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.