Weather Minimums

Weather Minimums (or weather minima) are the minimum visibility and ceiling values below which a specific operation (takeoff, approach, landing, or VFR flight) is not permitted.

• Takeoff minimums: Typically RVR 125m (Cat III) to 1,600m (Cat I) depending on available equipment
• Approach minimums: DA/DH for precision approaches, MDA for non-precision — vary by approach type and aircraft category
• VFR minimums: Vary by airspace class — typically 3 SM visibility with specific cloud clearances
• Alternate minimums: Higher than standard approach minimums — must forecast adequate weather at ETA

Minimums are published in approach procedures, AIP, and company operations manuals. Lower minimums require better ground equipment (ILS Cat II/III), aircraft certification, and crew training.