Challis, Idaho · field elev 4,277 ft
Density Altitude at Cougar Ranch (D47)
From a field elevation of 4,277 ft, a typical July afternoon at Cougar Ranch (86 °F) raises density altitude to about 6,925 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 | 25.0 | 3,032 ft | 34.1 | 3,653 ft |
| February | 29.2 | 3,320 ft | 40.4 | 4,075 ft |
| March | 37.4 | 3,875 ft | 49.8 | 4,692 ft |
| April | 44.0 | 4,313 ft | 57.3 | 5,174 ft ▲ |
| May | 52.4 | 4,860 ft | 66.6 | 5,760 ft ▲ |
| June | 59.5 | 5,314 ft | 75.0 | 6,279 ft ▲ |
| July | 67.1 | 5,791 ft | 85.7 | 6,925 ft ▲ |
| August | 65.6 | 5,698 ft | 85.0 | 6,883 ft ▲ |
| September | 57.5 | 5,187 ft | 75.9 | 6,334 ft ▲ |
| October | 45.8 | 4,431 ft | 60.7 | 5,390 ft ▲ |
| November | 33.1 | 3,585 ft | 43.0 | 4,247 ft |
| December | 24.2 | 2,977 ft | 33.3 | 3,599 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 D47
DENSITY ALTITUDE caution
Field elevation 4,277 ft — the air behaves like 6,943 ft.
- PRESSURE ALT
- 4,279 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
- 0U3 — Mahoney Creek Usfs
Mahoney Creek · elev 4,618 ft
- ID8 — Marble Creek
Challis · elev 4,685 ft
- 2U8 — Thomas Creek
Stanley · elev 4,415 ft
- C53 — Lower Loon Creek
Challis · elev 4,200 ft
- S81 — Indian Creek Usfs
Indian Creek · elev 4,718 ft
- U72 — Upper Loon Creek Usfs
Challis · elev 5,500 ft
- U54 — Bernard Usfs
Bernard · elev 3,626 ft
- 85U — Soldier Bar Usfs
Soldier Bar · elev 4,190 ft
Frequently asked questions
How high does density altitude get at D47 in summer?
On a typical July afternoon — around 86 °F at the nearest NOAA normals station — density altitude at Cougar Ranch reaches roughly 6,925 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 D47 on an average day?
It swings with the seasons: from roughly 2,977 ft at the coldest month's average temperature to about 5,791 ft at the warmest month's — all from a constant field elevation of 4,277 ft. The month-by-month table above carries the full year.
What is the field elevation of Cougar Ranch?
4,277 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is D47 (FAA), in Challis, Idaho.