Atomic City, Idaho · field elev 5,048 ft
Density Altitude at Coxs Well (U48)
Coxs Well is a genuine high-and-hot field: from 5,048 ft of elevation, a typical July afternoon (89 °F) pushes density altitude to about 8,042 ft — the airplane performs like it is 2,994 ft above the field before the wheels roll.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 16.9 | 3,431 ft | 28.1 | 4,204 ft |
| February | 21.9 | 3,779 ft | 33.3 | 4,555 ft |
| March | 33.7 | 4,582 ft | 46.2 | 5,407 ft ▲ |
| April | 42.6 | 5,172 ft | 57.1 | 6,107 ft ▲ |
| May | 52.0 | 5,782 ft | 67.3 | 6,745 ft ▲ |
| June | 60.5 | 6,321 ft | 77.3 | 7,356 ft ▲ |
| July | 69.3 | 6,868 ft | 88.8 | 8,042 ft ⚠ |
| August | 67.2 | 6,739 ft | 86.7 | 7,918 ft ▲ |
| September | 57.0 | 6,101 ft | 75.7 | 7,259 ft ▲ |
| October | 43.5 | 5,231 ft | 59.6 | 6,265 ft ▲ |
| November | 29.4 | 4,292 ft | 42.3 | 5,153 ft ▲ |
| December | 18.2 | 3,522 ft | 29.3 | 4,285 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 U48
DENSITY ALTITUDE high DA
Field elevation 5,048 ft — the air behaves like 8,053 ft.
- PRESSURE ALT
- 5,050 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 Idaho fields
- U46 — Big Southern Butte
Atomic City · elev 5,073 ft
- 1U0 — Bear Trap
Minidoka · elev 4,716 ft
- 0U7 — Hollow Top
Carey · elev 5,359 ft
- U37 — Midway
Atomic City · elev 5,017 ft
- U36 — Aberdeen Municipal
Aberdeen · elev 4,474 ft
- KAOC — Arco-Butte County
Arco · elev 5,335 ft
- U99 — Laidlaw Corrals
Kimama · elev 4,448 ft
- 2U4 — Rockford Municipal
Rockford · elev 4,465 ft
Frequently asked questions
How high does density altitude get at U48 in summer?
On a typical July afternoon — around 89 °F at the nearest NOAA normals station — density altitude at Coxs Well reaches roughly 8,042 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 U48 on an average day?
It swings with the seasons: from roughly 3,431 ft at the coldest month's average temperature to about 6,868 ft at the warmest month's — all from a constant field elevation of 5,048 ft. The month-by-month table above carries the full year.
What is the field elevation of Coxs Well?
5,048 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is U48 (FAA), in Atomic City, Idaho.