VFR, MVFR, IFR and LIFR flight categories
Aviation weather displays often summarize ceiling and visibility with color-coded flight categories. These categories are useful for quickly scanning conditions, but they are not the same thing as a legal determination that a particular flight may or may not be conducted.
VFR
The Aviation Weather Center commonly classifies VFR as ceiling greater than 3,000 feet AGL and visibility greater than 5 statute miles.
MVFR
Marginal VFR is commonly shown when ceiling is 1,000 to 3,000 feet AGL and/or visibility is 3 to 5 statute miles.
IFR
IFR category is commonly shown when ceiling is 500 feet to below 1,000 feet AGL and/or visibility is 1 mile to less than 3 miles.
LIFR
Low IFR is commonly shown when ceiling is below 500 feet AGL and/or visibility is less than 1 statute mile.
The lowest factor controls the category
Because the categories use ceiling and/or visibility, good visibility does not make the category VFR if the ceiling is low. Likewise, a high ceiling does not overcome very poor visibility.
Category is not a complete go/no-go decision
Regulatory weather minimums depend on airspace, operation, approach, pilot qualifications and other factors. Weather hazards such as thunderstorms, icing, turbulence or strong wind may also matter even when the category is VFR.
Use current observations and forecasts
METARs provide observations while TAFs and other products help describe forecast conditions. The category shown on a map is a summary of selected values, not a full briefing.
Related PilotDesk guides
METAR and TAF guide · Ceiling and visibility · Cloud-base estimate
Aviation Weather Center flight-category reference ↗