Williamstown, New Jersey · field elev 145 ft

Density Altitude at Southern Cross (C01)

Southern Cross sits at 145 ft, and even a typical July afternoon (87 °F) only lifts density altitude to about 1,968 ft — heat still trims performance, but the field rarely turns high-and-hot.

worst typical month: July · ≈1,968 ft station: GLASSBORO 2 NE · 7 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at GLASSBORO 2 NE (7 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 −1,554 ft 41.3 −992 ft
February 35.1 −1,421 ft 44.2 −794 ft
March 42.6 −903 ft 52.0 −267 ft
April 52.5 −234 ft 63.6 498 ft
May 62.3 413 ft 72.5 1,071 ft
June 71.9 1,033 ft 82.0 1,670 ft
July 77.0 1,356 ft 86.8 1,968 ft
August 75.2 1,243 ft 84.6 1,832 ft
September 69.1 854 ft 78.7 1,463 ft
October 56.3 19 ft 66.8 706 ft
November 45.8 −685 ft 55.1 −60 ft
December 38.0 −1,220 ft 46.0 −671 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 C01

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 1,980 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 1,980 ft

Field elevation 145 ft — the air behaves like 1,980 ft.

PRESSURE ALT
146 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 New Jersey fields

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Frequently asked questions

How high does density altitude get at C01 in summer?

On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Southern Cross reaches roughly 1,968 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 C01 on an average day?

It swings with the seasons: from roughly −1,554 ft at the coldest month's average temperature to about 1,356 ft at the warmest month's — all from a constant field elevation of 145 ft. The month-by-month table above carries the full year.

What is the field elevation of Southern Cross?

145 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is C01 (FAA), in Williamstown, New Jersey.