Deer Lodge, Montana · field elev 4,693 ft
Density Altitude at Deer Lodge-City-County (38S)
From a field elevation of 4,693 ft, a typical August afternoon at Deer Lodge-City-County (79 °F) raises density altitude to about 7,052 ft — solidly into the range where performance charts deserve a close read.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 22.0 | 3,343 ft | 33.2 | 4,108 ft |
| February | 24.5 | 3,516 ft | 36.0 | 4,296 ft |
| March | 31.8 | 4,014 ft | 44.3 | 4,846 ft |
| April | 39.4 | 4,523 ft | 52.9 | 5,403 ft ▲ |
| May | 47.9 | 5,081 ft | 62.2 | 5,994 ft ▲ |
| June | 54.1 | 5,480 ft | 68.5 | 6,386 ft ▲ |
| July | 61.6 | 5,956 ft | 79.1 | 7,034 ft ▲ |
| August | 60.8 | 5,906 ft | 79.4 | 7,052 ft ▲ |
| September | 52.1 | 5,352 ft | 69.6 | 6,454 ft ▲ |
| October | 40.6 | 4,602 ft | 55.4 | 5,563 ft ▲ |
| November | 28.3 | 3,776 ft | 40.2 | 4,576 ft |
| December | 20.9 | 3,267 ft | 31.3 | 3,980 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 38S
DENSITY ALTITUDE caution
Field elevation 4,693 ft — the air behaves like 7,027 ft.
- PRESSURE ALT
- 4,695 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 Montana fields
- 3U3 — Bowman Field
Anaconda · elev 5,034 ft
- U05 — Riddick Field
Philipsburg · elev 5,219 ft
- M26 — Drummond
Drummond · elev 4,245 ft
- KBTM — Bert Mooney
Butte · elev 5,551 ft
- 3U9 — Boulder
Boulder · elev 4,968 ft
- S69 — Lincoln
Lincoln · elev 4,603 ft
- KHLN — Helena Regional
Helena · elev 3,877 ft
- 02T — Wise River
Wise River · elev 5,830 ft
Frequently asked questions
How high does density altitude get at 38S in summer?
On a typical August afternoon — around 79 °F at the nearest NOAA normals station — density altitude at Deer Lodge-City-County reaches roughly 7,052 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 38S on an average day?
It swings with the seasons: from roughly 3,267 ft at the coldest month's average temperature to about 5,956 ft at the warmest month's — all from a constant field elevation of 4,693 ft. The month-by-month table above carries the full year.
What is the field elevation of Deer Lodge-City-County?
4,693 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 38S (FAA), in Deer Lodge, Montana.