VFR Weather Minimums Explained (Cloud Clearance and Visibility)

Why These Numbers Exist

VFR weather minimums, set by 14 CFR 91.155, guarantee two things: that you can see far enough to spot traffic, and that you stay far enough from clouds that an airplane popping out of one has room to avoid you. The required visibility and cloud clearances change with airspace and altitude, and the FAA expects you to know the table cold.

The Core Table

The pattern most of the airspace follows is "3-152" — 3 statute miles visibility, and cloud clearance of 500 ft below, 1,000 ft above, 2,000 ft horizontal. That applies in Class C, D, and E below 10,000 ft MSL. From there, learn the exceptions:

• Class B — 3 SM visibility and simply clear of clouds (you're under positive control, so you can be right up against them).
• Class E at or above 10,000 ft MSL — visibility jumps to 5 SM, with 1,000 ft below, 1,000 ft above, and 1 SM horizontal (aircraft move faster up high, so you need more room).
• Class G (uncontrolled), day, at or below 1,200 ft AGL — 1 SM and clear of clouds.
• Class G, night, at or below 1,200 ft AGL — back to 3 SM and 500/1,000/2,000 (with a limited exception in the traffic pattern).

Higher in Class G the numbers step up again, and above 10,000 ft MSL they match the 5 SM / 1,000-1,000-1-mile rule.

Basic VFR for the Airport Environment

To operate under basic VFR in the traffic pattern of a Class B, C, D, or E surface-area airport, you generally need at least a 3 SM visibility and a 1,000-ft ceiling. Below that you're in marginal or IFR conditions and need a clearance.

Special VFR — the Escape Hatch

Special VFR (SVFR) lets you operate in a controlled surface area with as little as 1 SM visibility and clear of clouds, but only with an ATC clearance and only in that surface area. At night it requires an instrument rating and an instrument-equipped airplane. It's a tool for getting in or out of a field under a low layer — not a license to scud-run cross-country.

Making It Stick

Don't memorize a wall of numbers — anchor on 3-152 as the default, then attach the four exceptions (Class B clear-of-clouds, above 10,000 the 5-mile rule, Class G day 1-mile, and the night change). On the exam you'll be given an airspace and altitude and asked for the required visibility or cloud clearance, or shown a scenario and asked whether the weather is legal. Picture the airspace first, then read the number off the pattern.

Aviation Test Prep drills this exact topic with ACS-aligned questions and worked explanations, and its Smart Review resurfaces the ones you miss until they stick — so a concept like this becomes an automatic point on test day instead of a coin flip.