Porthill, Idaho · field elev 1,758 ft
Density Altitude at Eckhart International (1S1)
Eckhart International sits at 1,758 ft, and even a typical August afternoon (86 °F) only lifts density altitude to about 3,859 ft — heat still trims performance, but the field rarely turns high-and-hot.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 28.2 | 112 ft | 35.5 | 618 ft |
| February | 31.1 | 314 ft | 40.2 | 939 ft |
| March | 38.8 | 843 ft | 50.0 | 1,596 ft |
| April | 47.1 | 1,403 ft | 60.4 | 2,277 ft |
| May | 56.4 | 2,017 ft | 70.7 | 2,935 ft |
| June | 61.9 | 2,374 ft | 75.7 | 3,249 ft |
| July | 68.8 | 2,815 ft | 85.5 | 3,853 ft |
| August | 67.6 | 2,739 ft | 85.6 | 3,859 ft |
| September | 58.1 | 2,128 ft | 74.1 | 3,149 ft |
| October | 45.7 | 1,310 ft | 58.2 | 2,134 ft |
| November | 35.7 | 631 ft | 44.1 | 1,202 ft |
| December | 28.4 | 126 ft | 35.5 | 618 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 1S1
DENSITY ALTITUDE
Field elevation 1,758 ft — the air behaves like 3,884 ft.
- PRESSURE ALT
- 1,759 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
- 65S — Boundary County
Bonners Ferry · elev 2,337 ft
- 67S — Priest Lake Usfs
Nordman · elev 2,611 ft
- 66S — Cavanaugh Bay
Coolin · elev 2,484 ft
- KSZT — Sandpoint
Sandpoint · elev 2,131 ft
- 1S6 — Priest River
Priest River · elev 2,193 ft
- S77 — Magee
Coeur D'Alene · elev 3,002 ft
- KCOE — Coeur D'Alene
Coeur D'Alene · elev 2,320 ft
- S83 — Shoshone County
Kellogg · elev 2,227 ft
Frequently asked questions
How high does density altitude get at 1S1 in summer?
On a typical August afternoon — around 86 °F at the nearest NOAA normals station — density altitude at Eckhart International reaches roughly 3,859 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 1S1 on an average day?
It swings with the seasons: from roughly 112 ft at the coldest month's average temperature to about 2,815 ft at the warmest month's — all from a constant field elevation of 1,758 ft. The month-by-month table above carries the full year.
What is the field elevation of Eckhart International?
1,758 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 1S1 (FAA), in Porthill, Idaho.