What Is RVR (Runway Visual Range)?

The 30-second answer

RVR (Runway Visual Range) is the distance, in feet or meters, that a pilot in the touchdown zone can see down the runway. It's measured by transmissometers along the runway, not by a person looking out a window. RVR — not weather-station "visibility" — is the legal number that decides whether a takeoff or landing is allowed in low-visibility conditions.

Why it matters

When fog rolls in at SFO, ORD, or HEL, your flight may be delayed even though the airport "looks fine." That's because RVR has dropped below approach minimums.

Common minimums

• Cat I ILS approach: ~1,800 ft RVR.
• Cat II: ~1,200 ft.
• Cat IIIa: ~700 ft.
• Cat IIIb (autoland): ~150 ft.
• Cat IIIc: zero — almost never authorized in commercial ops.

Track delays driven by RVR

FlightyFlow factors observed RVR into its delay-risk model in fog-prone airports.