Donnelly, Idaho · field elev 4,860 ft
Density Altitude at Donald D Coski Meml (U84)
From a field elevation of 4,860 ft, a typical July afternoon at Donald D Coski Meml (81 °F) raises density altitude to about 7,351 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 | 22.1 | 3,558 ft | 30.6 | 4,140 ft |
| February | 24.9 | 3,751 ft | 35.2 | 4,450 ft |
| March | 31.5 | 4,201 ft | 42.1 | 4,907 ft |
| April | 38.8 | 4,689 ft | 49.9 | 5,416 ft ▲ |
| May | 48.5 | 5,325 ft | 61.1 | 6,129 ft ▲ |
| June | 55.3 | 5,762 ft | 69.0 | 6,621 ft ▲ |
| July | 64.1 | 6,317 ft | 81.0 | 7,351 ft ▲ |
| August | 62.9 | 6,242 ft | 80.5 | 7,321 ft ▲ |
| September | 54.2 | 5,692 ft | 70.6 | 6,719 ft ▲ |
| October | 42.5 | 4,934 ft | 55.6 | 5,781 ft ▲ |
| November | 30.9 | 4,160 ft | 40.4 | 4,795 ft |
| December | 22.0 | 3,551 ft | 30.1 | 4,106 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 U84
DENSITY ALTITUDE caution
Field elevation 4,860 ft — the air behaves like 7,351 ft.
- PRESSURE ALT
- 4,862 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
- KMYL — Mc Call Municipal
Mc Call · elev 5,024 ft
- U70 — Cascade
Cascade · elev 4,748 ft
- U82 — Council Municipal
Council · elev 2,966 ft
- 1U4 — New Meadows
New Meadows · elev 3,908 ft
- I92 — Reed Ranch
Yellow Pine · elev 4,157 ft
- 24K — Krassel Usfs
Mc Call · elev 3,982 ft
- 0U0 — Landmark Usfs
Landmark · elev 6,662 ft
- 3U2 — Johnson Creek
Yellow Pine · elev 4,960 ft
Frequently asked questions
How high does density altitude get at U84 in summer?
On a typical July afternoon — around 81 °F at the nearest NOAA normals station — density altitude at Donald D Coski Meml reaches roughly 7,351 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 U84 on an average day?
It swings with the seasons: from roughly 3,551 ft at the coldest month's average temperature to about 6,317 ft at the warmest month's — all from a constant field elevation of 4,860 ft. The month-by-month table above carries the full year.
What is the field elevation of Donald D Coski Meml?
4,860 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is U84 (FAA), in Donnelly, Idaho.