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
68.1
51
61
71
76
58
February
72.4
58
61
70
83
80
March
83.2
84
79
71
93
94
April
93.1
94
94
98
93
May
96.3
95
96
95
98
June
95.4
95
95
94
95
July
93.8
95
97
75
99
August
85.4
78
94
68
98
September
85.1
86
77
90
75
October
84.3
81
79
91
69
November
81.6
79
80
77
84
December
76.5
59
72
84
87
Average
83.8
63.9
80.1
84.2
85.5
87.3
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.