St Augustine, Florida · field elev 10 ft

Density Altitude at St Augustine (KSGJ)

St Augustine sits at 10 ft, and even a typical July afternoon (91 °F) only lifts density altitude to about 2,061 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: July · ≈2,061 ft station: ST AUGUSTINE LIGHTHOUSE · 6 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at ST AUGUSTINE LIGHTHOUSE (6 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 57.6 −62 ft 67.5 585 ft
February 60.0 96 ft 69.7 726 ft
March 64.5 390 ft 74.4 1,026 ft
April 70.2 758 ft 79.8 1,367 ft
May 76.3 1,147 ft 85.1 1,698 ft
June 80.4 1,405 ft 88.6 1,914 ft
July 82.4 1,530 ft 91.0 2,061 ft
August 82.1 1,511 ft 89.9 1,994 ft
September 80.3 1,399 ft 87.4 1,840 ft
October 74.2 1,014 ft 81.8 1,492 ft
November 66.2 501 ft 74.9 1,058 ft
December 60.1 103 ft 68.9 675 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 KSGJ

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 2,061 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 2,061 ft

Field elevation 10 ft — the air behaves like 2,061 ft.

PRESSURE ALT
11 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 Florida fields

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Frequently asked questions

How high does density altitude get at KSGJ in summer?

On a typical July afternoon — around 91 °F at the nearest NOAA normals station — density altitude at St Augustine reaches roughly 2,061 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 KSGJ on an average day?

It swings with the seasons: from roughly −62 ft at the coldest month's average temperature to about 1,530 ft at the warmest month's — all from a constant field elevation of 10 ft. The month-by-month table above carries the full year.

What is the field elevation of St Augustine?

10 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KSGJ (ICAO) / SGJ (FAA), in St Augustine, Florida.