Twin Falls, Idaho · field elev 4,153 ft
Density Altitude at Joslin Field/Magic Valley Regional (KTWF)
From a field elevation of 4,153 ft, a typical July afternoon at Joslin Field/Magic Valley Regional (88 °F) raises density altitude to about 6,935 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 | 3,159 ft | 37.0 | 3,694 ft |
| February | 32.8 | 3,411 ft | 41.8 | 4,014 ft |
| March | 40.9 | 3,954 ft | 52.2 | 4,694 ft |
| April | 46.5 | 4,324 ft | 58.7 | 5,111 ft ▲ |
| May | 55.4 | 4,900 ft | 68.7 | 5,739 ft ▲ |
| June | 63.8 | 5,433 ft | 78.2 | 6,323 ft ▲ |
| July | 73.0 | 6,005 ft | 88.4 | 6,935 ft ▲ |
| August | 71.3 | 5,900 ft | 86.8 | 6,840 ft ▲ |
| September | 61.8 | 5,307 ft | 76.4 | 6,213 ft ▲ |
| October | 49.3 | 4,506 ft | 62.3 | 5,339 ft ▲ |
| November | 36.6 | 3,667 ft | 47.2 | 4,369 ft |
| December | 28.5 | 3,118 ft | 36.9 | 3,688 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 KTWF
DENSITY ALTITUDE caution
Field elevation 4,153 ft — the air behaves like 6,911 ft.
- PRESSURE ALT
- 4,155 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
- KJER — Jerome County
Jerome · elev 4,053 ft
- U03 — Buhl Municipal
Buhl · elev 3,663 ft
- U94 — Hazelton Municipal
Hazelton · elev 4,172 ft
- KGNG — Gooding Municipal
Gooding · elev 3,732 ft
- 1U6 — Oakley Municipal
Oakley · elev 4,664 ft
- KBYI — Burley Municipal
Burley · elev 4,154 ft
- U89 — Glenns Ferry Municipal
Glenns Ferry · elev 2,536 ft
- 3U0 — Murphy Hot Springs
Three Creek · elev 5,829 ft
Frequently asked questions
How high does density altitude get at KTWF in summer?
On a typical July afternoon — around 88 °F at the nearest NOAA normals station — density altitude at Joslin Field/Magic Valley Regional reaches roughly 6,935 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 KTWF on an average day?
It swings with the seasons: from roughly 3,118 ft at the coldest month's average temperature to about 6,005 ft at the warmest month's — all from a constant field elevation of 4,153 ft. The month-by-month table above carries the full year.
What is the field elevation of Joslin Field/Magic Valley Regional?
4,153 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KTWF (ICAO) / TWF (FAA), in Twin Falls, Idaho.