Carbondale/Murphysboro, Illinois · field elev 411 ft

Density Altitude at Southern Illinois (KMDH)

Southern Illinois sits at 411 ft, and even a typical July afternoon (88 °F) only lifts density altitude to about 2,390 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: July · ≈2,390 ft station: CARBONDALE SOUTHERN IL AP · 0 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at CARBONDALE SOUTHERN IL AP (0 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 33.2 −1,222 ft 41.7 −634 ft
February 37.5 −923 ft 47.2 −260 ft
March 46.5 −307 ft 57.1 401 ft
April 56.7 374 ft 68.1 1,116 ft
May 66.2 994 ft 77.0 1,682 ft
June 74.9 1,550 ft 85.7 2,224 ft
July 78.0 1,745 ft 88.4 2,390 ft
August 76.0 1,619 ft 87.2 2,317 ft
September 68.3 1,129 ft 80.8 1,920 ft
October 57.4 420 ft 70.1 1,245 ft
November 45.6 −368 ft 56.2 341 ft
December 37.0 −957 ft 45.7 −361 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 KMDH

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 2,366 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 2,366 ft

Field elevation 411 ft — the air behaves like 2,366 ft.

PRESSURE ALT
412 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 Illinois fields

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Frequently asked questions

How high does density altitude get at KMDH in summer?

On a typical July afternoon — around 88 °F at the nearest NOAA normals station — density altitude at Southern Illinois reaches roughly 2,390 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 KMDH on an average day?

It swings with the seasons: from roughly −1,222 ft at the coldest month's average temperature to about 1,745 ft at the warmest month's — all from a constant field elevation of 411 ft. The month-by-month table above carries the full year.

What is the field elevation of Southern Illinois?

411 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KMDH (ICAO) / MDH (FAA), in Carbondale/Murphysboro, Illinois.