Herlong, California · field elev 4,062 ft

Density Altitude at Herlong (H37)

From a field elevation of 4,062 ft, a typical July afternoon at Herlong (88 °F) raises density altitude to about 6,801 ft — solidly into the range where performance charts deserve a close read.

worst typical month: July · ≈6,801 ft station: DOYLE 4 SSE · 13 mi away normals vintage 1991–2020

Typical density altitude by month

From NOAA 1991–2020 monthly normals at DOYLE 4 SSE (13 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 33.3 3,332 ft 42.8 3,968 ft
February 37.9 3,642 ft 48.5 4,342 ft
March 43.5 4,014 ft 55.6 4,801 ft
April 47.6 4,283 ft 61.5 5,177 ft ▲
May 55.2 4,776 ft 69.9 5,703 ft ▲
June 62.4 5,234 ft 79.4 6,285 ft ▲
July 69.5 5,678 ft 88.0 6,801 ft ▲
August 68.0 5,585 ft 87.1 6,748 ft ▲
September 61.6 5,183 ft 79.8 6,309 ft ▲
October 51.7 4,550 ft 67.2 5,535 ft ▲
November 40.1 3,789 ft 51.9 4,563 ft
December 33.0 3,312 ft 42.1 3,921 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 H37

Altimeter-style gauge: field elevation and density altitude needles 03691215 DENSITY ALT ×1,000 FT 6,801 DENSITY ALTITUDE · FEET
field elevation density altitude

DENSITY ALTITUDE 6,801 ft caution

Field elevation 4,062 ft — the air behaves like 6,801 ft.

PRESSURE ALT
4,064 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 H37 in summer?

On a typical July afternoon — around 88 °F at the nearest NOAA normals station — density altitude at Herlong reaches roughly 6,801 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 H37 on an average day?

It swings with the seasons: from roughly 3,312 ft at the coldest month's average temperature to about 5,678 ft at the warmest month's — all from a constant field elevation of 4,062 ft. The month-by-month table above carries the full year.

What is the field elevation of Herlong?

4,062 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is H37 (FAA), in Herlong, California.