San Augustine, Texas · field elev 443 ft

Density Altitude at San Augustine County (78R)

San Augustine County sits at 443 ft, and even a typical August afternoon (94 °F) only lifts density altitude to about 2,794 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: August · ≈2,794 ft station: SAN AUGUSTINE · 3 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at SAN AUGUSTINE (3 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 47.4 −207 ft 59.5 598 ft
February 51.1 42 ft 63.2 839 ft
March 57.7 480 ft 70.2 1,290 ft
April 64.7 937 ft 76.9 1,715 ft
May 72.5 1,437 ft 84.0 2,158 ft
June 79.0 1,847 ft 90.3 2,545 ft
July 82.0 2,034 ft 93.5 2,740 ft
August 82.1 2,040 ft 94.4 2,794 ft
September 76.4 1,684 ft 88.5 2,435 ft
October 66.5 1,053 ft 79.5 1,878 ft
November 56.6 407 ft 69.7 1,258 ft
December 48.8 −112 ft 61.0 696 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 78R

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 2,770 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 2,770 ft

Field elevation 443 ft — the air behaves like 2,770 ft.

PRESSURE ALT
444 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

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Frequently asked questions

How high does density altitude get at 78R in summer?

On a typical August afternoon — around 94 °F at the nearest NOAA normals station — density altitude at San Augustine County reaches roughly 2,794 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 78R on an average day?

It swings with the seasons: from roughly −207 ft at the coldest month's average temperature to about 2,040 ft at the warmest month's — all from a constant field elevation of 443 ft. The month-by-month table above carries the full year.

What is the field elevation of San Augustine County?

443 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 78R (FAA), in San Augustine, Texas.