VFR weather minimums finder and drill

How to read the minimums

Each row of 14 CFR 91.155(a) gives two minimums: the flight visibility you need, and how far you must stay from clouds.¹ Flight visibility is the average forward horizontal distance from the cockpit at which you can see and identify prominent objects.² Those are unlighted objects by day and lighted objects by night.²

The distance from clouds has up to three parts: below, above and horizontal.¹ Picture a box around every cloud that you stay outside of. In Class B, and in Class G at 1,200 feet or less above the surface by day, the rule is simply “clear of clouds”.¹

Class E’s dividing line is 10,000 feet MSL.¹ Class G’s lowest band is measured above the surface, regardless of MSL altitude.¹ For these minimums, at the base altitude of a Class E area you count as being in the airspace directly below it.¹

Day and night

Night is the time between the end of evening civil twilight and the beginning of morning civil twilight.² The times are those published in the Air Almanac, converted to local time.²

Classes B, C, D and E have no separate night row, so their minimums are the same day and night.¹ Class G changes at night below 10,000 feet MSL, and at 1,200 feet or less above the surface at any MSL altitude.¹

In those bands, an airplane needs 3 statute miles of visibility at night instead of 1.¹ At 1,200 feet or less above the surface, “clear of clouds” becomes 500 feet below, 1,000 feet above and 2,000 feet horizontal.¹

Exceptions in Class G

At night in Class G below 1,200 feet above the surface, an airplane may fly clear of clouds in one case.¹ It must be in an airport traffic pattern within 1/2 mile of the runway, with visibility of at least 1 statute mile.¹ Helicopters have their own Class G minimums and exceptions.¹

Near airports: ceiling and ground visibility

Two more parts of 91.155 apply near airports with controlled airspace down to the surface:¹

• When the ceiling is less than 1,000 feet, you may not fly VFR beneath it.¹ This applies within the lateral boundaries of controlled airspace designated to the surface for an airport.¹
• Ground visibility at the airport must be at least 3 statute miles to take off, land or enter its traffic pattern.¹ This applies in the surface area of Class B, C, D or E airspace designated for an airport.¹ Where ground visibility isn’t reported, flight visibility must be at least 3 statute miles.¹

A ceiling is the height above the earth’s surface of the lowest layer of clouds or obscuring phenomena reported as “broken”, “overcast” or “obscuration”.² A layer classified as “thin” or “partial” isn’t a ceiling.²

Special VFR

Under special VFR, you may fly by the minimums in 91.157 instead of those in 91.155.³ It applies below 10,000 feet MSL, within the upward extension of the lateral boundaries of controlled airspace designated to the surface for an airport.³ You need an ATC clearance and must stay clear of clouds.³

For airplanes, flight visibility must be at least 1 statute mile, and flights are limited to between sunrise and sunset.³ In Alaska, the limit is instead while the sun is 6 degrees or less below the horizon.³ At other times, the pilot must meet Part 61’s requirements for instrument flight, and the aircraft must be equipped as 91.205(d) requires.³

To take off or land an airplane under special VFR, ground visibility must be at least 1 statute mile.³ If ground visibility isn’t reported, flight visibility must be at least 1 statute mile.³ Part 91’s appendix D, section 3, lists the locations where fixed-wing special VFR is prohibited.³⁴

Class A

Class A has no VFR minimums: 91.155 lists it as “not applicable”.¹ Flights there must be conducted under IFR, with an ATC clearance received before entering, unless ATC authorizes a deviation.⁵

Part 107 drone minimums

A drone flown under Part 107 has one set of weather minimums, whatever the airspace class.⁶ Flight visibility, as observed from the control station, must be at least 3 statute miles.⁶ The drone must stay at least 500 feet below clouds and 2,000 feet horizontally from them.⁶

Here, flight visibility is the average slant distance from the control station at which prominent objects can be seen and identified.⁶ Those are unlighted objects by day and lighted objects by night.⁶ The rule sets no distance above clouds.⁶

The drone may not fly higher than 400 feet above ground level.⁶ Within a 400-foot radius of a structure, it may fly up to 400 feet above the structure’s top.⁶

You also need prior authorization from ATC in Class B, C or D airspace.⁷ The same goes within the lateral boundaries of the surface area of Class E airspace designated for an airport.⁷

StudyWren is an independent study tool and isn’t affiliated with the FAA.

Sources

1. 14 CFR 91.155, “Basic VFR weather minimums,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-91.155 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰

2. 14 CFR 1.1, “General definitions” (“Ceiling,” “Flight visibility” and “Night”), eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-1.1 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. 14 CFR 91.157, “Special VFR weather minimums,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-91.157 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

4. 14 CFR part 91, appendix D, section 3, “Locations at which fixed-wing Special VFR operations are prohibited,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/part-91/appendix-Appendix%20D%20to%20Part%2091 ↩

5. 14 CFR 91.135, “Operations in Class A airspace,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-91.135 ↩

6. 14 CFR 107.51, “Operating limitations for small unmanned aircraft,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-107.51 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

7. 14 CFR 107.41, “Operation in certain airspace,” eCFR (current as of 2026-10-22). https://www.ecfr.gov/current/title-14/section-107.41 ↩ ↩²