Gaithersburg, Maryland · field elev 539 ft

Density Altitude at Montgomery County Airpark (KGAI)

Montgomery County Airpark sits at 539 ft, and even a typical July afternoon (87 °F) only lifts density altitude to about 2,466 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: July · ≈2,466 ft station: ROCKVILLE 1 NE · 5 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at ROCKVILLE 1 NE (5 mi from the field) · standard pressure, dry air
Month Avg temp °F DA at avg temp Afternoon high °F DA on a typical afternoon
January 34.5 −971 ft 42.2 −440 ft
February 36.7 −818 ft 45.0 −250 ft
March 44.8 −263 ft 53.7 334 ft
April 55.7 466 ft 65.9 1,132 ft
May 64.6 1,048 ft 74.3 1,669 ft
June 72.9 1,580 ft 82.2 2,164 ft
July 78.0 1,902 ft 87.1 2,466 ft
August 75.9 1,770 ft 84.9 2,331 ft
September 68.7 1,312 ft 77.5 1,870 ft
October 57.0 552 ft 65.9 1,132 ft
November 46.9 −121 ft 55.7 466 ft
December 38.5 −694 ft 46.0 −182 ft

▲ above 5,000 ft · ⚠ above 8,000 ft. These are planning references at standard pressure and dry air — afternoon humidity and low pressure both push the real number higher. Run today's values below.

Run today’s numbers for KGAI

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 2,460 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 2,460 ft

Field elevation 539 ft — the air behaves like 2,460 ft.

PRESSURE ALT
540 ft
ISA DEVIATION
RULE-OF-THUMB DA
AIR DENSITY INDEX
AIR DENSITY
WATER · GRAINS/LB

For training and reference · verify with official sources and your POH before flight · no tool on this site renders a go / no-go judgment

Nearby Maryland fields

All Maryland airports →

Frequently asked questions

How high does density altitude get at KGAI in summer?

On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Montgomery County Airpark reaches roughly 2,466 ft at standard pressure. Hotter-than-normal days, low pressure, and humidity all push it higher, so run the day's actual numbers before flying.

What is the density altitude at KGAI on an average day?

It swings with the seasons: from roughly −971 ft at the coldest month's average temperature to about 1,902 ft at the warmest month's — all from a constant field elevation of 539 ft. The month-by-month table above carries the full year.

What is the field elevation of Montgomery County Airpark?

539 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KGAI (ICAO) / GAI (FAA), in Gaithersburg, Maryland.