Dauphin Island, Alabama · field elev 5 ft

Density Altitude at Jeremiah Denton (4R9)

Jeremiah Denton sits at 5 ft, and even a typical July afternoon (88 °F) only lifts density altitude to about 1,883 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: July · ≈1,883 ft station: DAUPHIN IS #2 · 3 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at DAUPHIN IS #2 (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 52.3 −420 ft 58.6 −2 ft
February 55.4 −214 ft 61.5 189 ft
March 61.3 175 ft 66.8 533 ft
April 68.3 630 ft 73.5 963 ft
May 76.0 1,122 ft 80.8 1,424 ft
June 81.3 1,455 ft 86.2 1,760 ft
July 83.2 1,574 ft 88.2 1,883 ft
August 83.2 1,574 ft 88.1 1,877 ft
September 80.3 1,392 ft 85.2 1,698 ft
October 72.0 867 ft 77.4 1,210 ft
November 61.7 202 ft 67.8 598 ft
December 55.2 −227 ft 61.2 169 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 4R9

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 1,871 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 1,871 ft

Field elevation 5 ft — the air behaves like 1,871 ft.

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

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Frequently asked questions

How high does density altitude get at 4R9 in summer?

On a typical July afternoon — around 88 °F at the nearest NOAA normals station — density altitude at Jeremiah Denton reaches roughly 1,883 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 4R9 on an average day?

It swings with the seasons: from roughly −420 ft at the coldest month's average temperature to about 1,574 ft at the warmest month's — all from a constant field elevation of 5 ft. The month-by-month table above carries the full year.

What is the field elevation of Jeremiah Denton?

5 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4R9 (FAA), in Dauphin Island, Alabama.