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
86.2
84
87
82
87
88
February
86.0
91
93
91
76
91
March
86.0
89
69
30
97
87
April
92.3
90
98
98
84
May
95.4
99
96
97
96
June
98.1
100
100
97
98
July
98.6
100
97
96
99
August
98.0
99
99
99
100
September
95.8
100
88
99
96
October
92.5
95
97
94
88
November
79.5
82
60
91
63
December
86.1
91
76
89
89
Average
91.1
87.8
92.4
89.1
94.1
90.7
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.