FAR Ninety-One Point One Fifty-Five, the VFR Minimums Table, and Why the Cloud Clearance Numbers Change When the Airspace Does

The answer to “how close can you legally fly to a cloud” depends on your airspace class, your altitude, and whether it is day or night. FAR 91.155 codifies these requirements in a table that many pilots memorize without understanding - and that misunderstanding shows up on checkrides and, more dangerously, in actual marginal conditions. Two factors drive every number in that table: speed and support - how fast aircraft are moving, and whether ATC is providing traffic separation.

What Are the VFR Minimums in Class A Airspace?

Class A airspace begins at 18,000 feet MSL. There is no VFR operation in Class A. All flight is conducted under Instrument Flight Rules (IFR). Class A does not appear in the VFR minimums table.

What Are the VFR Cloud Clearance Requirements in Class B Airspace?

Class B airspace requires 3 statute miles of flight visibility and clear of clouds - no specific vertical or horizontal distance from clouds is required.

This is the most permissive cloud clearance in the table, and it is permissive for a specific reason. When you enter Class B, ATC has issued you a clearance and is actively providing separation for every aircraft in that airspace. Because radar backup handles the separation work, the regulation only requires that you stay out of the clouds and maintain visibility.

One point that surprises many students: in Class B you can legally be immediately below a cloud layer as long as you are not inside it. In Class E at the same altitude, you would need 500 feet of vertical buffer below that same cloud. The difference is that ATC support in Class B replaces the separation buffer your eyes would otherwise need to provide.

What Are the VFR Minimums in Class C and Class D Airspace?

Both Class C and Class D require 3 statute miles of flight visibility and the same cloud clearance package: 500 feet below the cloud base, 1,000 feet above, and 2,000 feet horizontally.

In Class C and D, you have communication requirements and radar service (in Class C), but ATC is not providing separation from every aircraft at every moment. See-and-avoid remains your responsibility in many situations. The buffer around clouds exists so that if an instrument aircraft descends out of a cloud base, you have time to see it and react.

What Are the VFR Minimums in Class E Airspace?

Class E below 10,000 feet MSL uses the same numbers as Class C and D: 3 statute miles visibility, 500 feet below, 1,000 feet above, 2,000 feet horizontal.

Class E at or above 10,000 feet MSL is where the first significant shift occurs. At altitude, aircraft move faster. A head-on closing speed of 400 knots covers roughly 10 miles every 90 seconds. At 3 miles of visibility, you may have only about 25 seconds to spot a conflict and maneuver.

The regulation responds by tightening requirements. At or above 10,000 feet MSL, flight visibility jumps to 5 statute miles. Cloud clearances expand to 1,000 feet below, 1,000 feet above, and 1 statute mile horizontally.

What Are the VFR Minimums in Class G Airspace?

Class G - uncontrolled airspace with no radar and no separation services - has the most layered section of the table. Requirements depend on both altitude and time of day.

Class G, at or below 1,200 feet AGL, daytime:

• 1 statute mile flight visibility
• Clear of clouds (no specific distance required)

This is the most permissive VFR minimum in the entire table. It reflects the historically slow, local operations conducted at low altitudes in familiar terrain. During daylight at slow speeds, 1 mile provides sufficient visibility to navigate and avoid obstacles.

Class G, at or below 1,200 feet AGL, nighttime:

• 3 statute miles flight visibility
• 500 feet below, 1,000 feet above, 2,000 feet horizontal

Night removes visual terrain references and makes weather identification significantly harder. A dark haze layer at night looks nothing like it does in daylight. 2.5 miles of visibility in nighttime haze may not provide adequate terrain separation or let you identify a developing weather trend ahead. This is a common trap for pilots doing evening pattern work who forget that night minimums apply the moment official sunset has passed.

Class G, above 1,200 feet AGL, daytime, below 10,000 feet MSL:

• 1 statute mile visibility
• 500 feet below, 1,000 feet above, 2,000 feet horizontal

Cloud clearances appear at this altitude because the assumption of slow local operations no longer holds as firmly. Faster aircraft may share the same airspace.

Class G, above 1,200 feet AGL, nighttime, below 10,000 feet MSL:

• 3 statute miles visibility
• 500 feet below, 1,000 feet above, 2,000 feet horizontal

Class G, at or above 10,000 feet MSL:

• 5 statute miles visibility
• 1,000 feet below, 1,000 feet above, 1 statute mile horizontal

Same as high Class E - speed drives the requirements.

How Do I Read the VFR Minimums Table Without Memorizing Every Row?

The logic builds in a clear chain from most permissive to most restrictive.

1. Class G surface, daytime - the floor. 1 mile, clear of clouds. Low, slow, daylight.
2. Add night, or climb above 1,200 feet AGL in Class G - cloud clearances appear; night bumps visibility to 3 miles.
3. Controlled airspace below 10,000 feet - 3 miles and the 500 / 1,000 / 2,000 package.
4. Above 10,000 feet - speed demands more. 5 miles and expanded clearances.
5. Class B - 3 miles, clear of clouds. ATC separation relaxes the cloud distance requirement.
6. Class A - no VFR.

Three numbers appear together throughout the table: 500 feet below, 1,000 feet above, 2,000 feet horizontal. This package repeats in Class C, Class D, and Class E below 10,000 feet. It represents a consistent judgment about the buffer a pilot needs at mid-altitudes when doing their own traffic separation.

How Do I Apply VFR Minimums to Real Scenarios?

The ACS practical test will not ask you to recite the table. The examiner will set up a situation and watch you reason through it.

Scenario 1: You are flying cross-country at 7,500 feet in Class E airspace. A PIREP reports scattered clouds at 7,000 feet. Can you maintain legal VFR?

Class E below 10,000 MSL requires 1,000 feet of clearance above any clouds. You are at 7,500 feet; the cloud layer is at 7,000 feet. You are only 500 feet above the tops. You do not meet the requirement.

Your options: climb to at least 8,000 feet to place you 1,000 feet above the layer, or descend to 6,500 feet or lower to place you 500 feet below the base with 2,000 feet of horizontal separation maintained.

Scenario 2: You are approaching an uncontrolled airport in Class E airspace to the surface (dashed magenta ring on the sectional). Weather is 2 miles visibility, broken clouds at 1,200 feet. Is this legal VFR?

Class E below 10,000 feet requires 3 statute miles minimum visibility. Two miles does not meet it. This is a marginal situation the regulation already excludes from standard VFR - you are looking at a Special VFR request or remaining on the ground.

What Is Special VFR and When Can I Use It?

FAR 91.157 covers Special VFR. When weather falls below standard VFR minimums inside controlled airspace, a Special VFR clearance allows operation with 1 statute mile of flight visibility and clear of clouds. You request it from ATC, and they can approve or deny it based on traffic. Some airports specifically prohibit Special VFR for fixed-wing aircraft - that restriction is printed on the sectional chart.

Night Special VFR carries a critical restriction: if it is nighttime, a Special VFR clearance requires you to be instrument rated and your aircraft must be equipped for instrument flight. Night Special VFR in a VFR-only aircraft is not legal. This is not a detail to discover while weather is deteriorating on an evening departure.

Why the Legal Minimums Are Not the Same as the Safe Minimums

FAR 91.155 defines where the legal floor is. It does not define where the safe floor is.

Marginal VFR - conditions that technically meet the regulation but barely - is one of the most dangerous places a VFR pilot can operate. In clearly below-minimums weather, most pilots do not go. In marginal weather, rationalization takes hold: the destination looks reachable, the weather might improve, you’re mostly there. The minimums cannot protect you from that pull.

Understanding why every row in this table reads the way it does - not just what it says - gives you the framework to make a real decision rather than a rationalized one. When conditions are at the margins, that understanding matters more than the number itself.

The full minimums table appears in the FARs/AIM and in the Pilot’s Handbook of Aeronautical Knowledge. Read it through the lens of speed and support, not as a memorization exercise.

Key Takeaways

• Speed and support are the two factors behind every VFR minimum: how fast aircraft are moving, and whether ATC is providing separation.
• Class B requires 3 SM visibility and clear of clouds - the most permissive cloud clearance - because ATC handles separation in that airspace.
• The 500 / 1,000 / 2,000 cloud clearance package (below / above / horizontal) repeats in Class C, Class D, and Class E below 10,000 feet.
• Above 10,000 feet MSL, visibility increases to 5 SM and cloud clearances expand because higher speeds compress reaction time.
• Night VFR in Class G at or below 1,200 feet AGL requires 3 miles minimum visibility, not 1 - a common point of confusion for pilots transitioning to evening flight.
• Night Special VFR requires an instrument rating and an IFR-equipped aircraft, regardless of actual conditions.