Jerome, Idaho · field elev 4,053 ft
Density Altitude at Jerome County (KJER)
From a field elevation of 4,053 ft, a typical July afternoon at Jerome County (90 °F) raises density altitude to about 6,885 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 | 29.1 | 3,035 ft | 35.7 | 3,483 ft |
| February | 33.3 | 3,321 ft | 41.4 | 3,864 ft |
| March | 42.1 | 3,910 ft | 52.6 | 4,597 ft |
| April | 48.1 | 4,305 ft | 59.9 | 5,064 ft ▲ |
| May | 56.8 | 4,867 ft | 69.5 | 5,667 ft ▲ |
| June | 65.3 | 5,405 ft | 79.3 | 6,268 ft ▲ |
| July | 74.1 | 5,951 ft | 89.6 | 6,885 ft ▲ |
| August | 72.0 | 5,821 ft | 87.6 | 6,767 ft ▲ |
| September | 63.2 | 5,273 ft | 77.5 | 6,158 ft ▲ |
| October | 50.8 | 4,481 ft | 62.8 | 5,248 ft ▲ |
| November | 38.4 | 3,664 ft | 47.7 | 4,279 ft |
| December | 29.3 | 3,049 ft | 36.0 | 3,503 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 KJER
DENSITY ALTITUDE caution
Field elevation 4,053 ft — the air behaves like 6,909 ft.
- PRESSURE ALT
- 4,055 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
- KTWF — Joslin Field/Magic Valley Regional
Twin Falls · elev 4,153 ft
- U94 — Hazelton Municipal
Hazelton · elev 4,172 ft
- U03 — Buhl Municipal
Buhl · elev 3,663 ft
- KGNG — Gooding Municipal
Gooding · elev 3,732 ft
- KBYI — Burley Municipal
Burley · elev 4,154 ft
- U93 — Magic Reservoir
Hailey · elev 4,844 ft
- U99 — Laidlaw Corrals
Kimama · elev 4,448 ft
- 1U6 — Oakley Municipal
Oakley · elev 4,664 ft
Frequently asked questions
How high does density altitude get at KJER in summer?
On a typical July afternoon — around 90 °F at the nearest NOAA normals station — density altitude at Jerome County reaches roughly 6,885 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 KJER on an average day?
It swings with the seasons: from roughly 3,035 ft at the coldest month's average temperature to about 5,951 ft at the warmest month's — all from a constant field elevation of 4,053 ft. The month-by-month table above carries the full year.
What is the field elevation of Jerome County?
4,053 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KJER (ICAO) / JER (FAA), in Jerome, Idaho.