Sierraville, California · field elev 4,990 ft

Density Altitude at Sierraville Dearwater (O79)

From a field elevation of 4,990 ft, a typical July afternoon at Sierraville Dearwater (86 °F) raises density altitude to about 7,830 ft — solidly into the range where performance charts deserve a close read.

worst typical month: July · ≈7,830 ft station: PORTOLA · 17 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at PORTOLA (17 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 31.1 4,335 ft 43.0 5,127 ft ▲
February 33.7 4,510 ft 46.0 5,323 ft ▲
March 38.4 4,824 ft 51.6 5,685 ft ▲
April 43.4 5,153 ft 57.7 6,074 ft ▲
May 51.0 5,646 ft 67.0 6,656 ft ▲
June 58.7 6,137 ft 77.2 7,280 ft ▲
July 65.5 6,563 ft 86.4 7,830 ft ▲
August 63.9 6,463 ft 85.2 7,759 ft ▲
September 58.0 6,093 ft 78.8 7,376 ft ▲
October 48.1 5,459 ft 66.4 6,619 ft ▲
November 38.3 4,817 ft 52.5 5,743 ft ▲
December 30.7 4,308 ft 42.1 5,068 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 O79

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 7,806 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 7,806 ft caution

Field elevation 4,990 ft — the air behaves like 7,806 ft.

PRESSURE ALT
4,992 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 O79 in summer?

On a typical July afternoon — around 86 °F at the nearest NOAA normals station — density altitude at Sierraville Dearwater reaches roughly 7,830 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 O79 on an average day?

It swings with the seasons: from roughly 4,308 ft at the coldest month's average temperature to about 6,563 ft at the warmest month's — all from a constant field elevation of 4,990 ft. The month-by-month table above carries the full year.

What is the field elevation of Sierraville Dearwater?

4,990 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is O79 (FAA), in Sierraville, California.