St Johns, Arizona · field elev 5,737 ft

Density Altitude at St Johns Industrial Air Park (KSJN)

St Johns Industrial Air Park is a genuine high-and-hot field: from 5,737 ft of elevation, a typical July afternoon (91 °F) pushes density altitude to about 9,008 ft — the airplane performs like it is 3,271 ft above the field before the wheels roll.

worst typical month: July · ≈9,008 ft station: ST JOHNS INDUSTRIAL AP · 0 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at ST JOHNS INDUSTRIAL 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 34.4 5,482 ft 49.5 6,468 ft ▲
February 38.6 5,760 ft 54.6 6,793 ft ▲
March 45.1 6,185 ft 62.4 7,282 ft ▲
April 52.3 6,647 ft 69.9 7,745 ft ▲
May 61.4 7,220 ft 79.3 8,312 ft ⚠
June 71.5 7,842 ft 89.8 8,932 ft ⚠
July 75.9 8,108 ft 91.1 9,008 ft ⚠
August 73.2 7,945 ft 87.9 8,821 ft ⚠
September 66.6 7,542 ft 83.0 8,533 ft ⚠
October 54.4 6,780 ft 72.2 7,885 ft ▲
November 42.7 6,029 ft 59.6 7,108 ft ▲
December 33.6 5,429 ft 48.8 6,423 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 KSJN

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 9,002 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 9,002 ft high DA

Field elevation 5,737 ft — the air behaves like 9,002 ft.

PRESSURE ALT
5,739 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 Arizona fields

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Frequently asked questions

How high does density altitude get at KSJN in summer?

On a typical July afternoon — around 91 °F at the nearest NOAA normals station — density altitude at St Johns Industrial Air Park reaches roughly 9,008 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 KSJN on an average day?

It swings with the seasons: from roughly 5,429 ft at the coldest month's average temperature to about 8,108 ft at the warmest month's — all from a constant field elevation of 5,737 ft. The month-by-month table above carries the full year.

What is the field elevation of St Johns Industrial Air Park?

5,737 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KSJN (ICAO) / SJN (FAA), in St Johns, Arizona.