Mazama, Washington · field elev 2,415 ft
Density Altitude at Lost River (W12)
Lost River sits at 2,415 ft, and even a typical July afternoon (85 °F) only lifts density altitude to about 4,592 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 | 22.5 | 532 ft | 29.2 | 1,001 ft |
| February | 28.0 | 918 ft | 36.6 | 1,510 ft |
| March | 35.9 | 1,462 ft | 46.0 | 2,143 ft |
| April | 45.0 | 2,076 ft | 57.5 | 2,898 ft |
| May | 54.8 | 2,723 ft | 68.2 | 3,582 ft |
| June | 61.5 | 3,156 ft | 74.6 | 3,983 ft |
| July | 69.6 | 3,670 ft | 84.5 | 4,592 ft |
| August | 68.7 | 3,614 ft | 84.1 | 4,567 ft |
| September | 59.4 | 3,021 ft | 74.4 | 3,970 ft |
| October | 45.0 | 2,076 ft | 56.5 | 2,833 ft |
| November | 31.7 | 1,174 ft | 38.5 | 1,639 ft |
| December | 22.3 | 518 ft | 28.2 | 932 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 W12
DENSITY ALTITUDE
Field elevation 2,415 ft — the air behaves like 4,622 ft.
- PRESSURE ALT
- 2,416 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 Washington fields
- S52 — Methow Valley State
Winthrop · elev 1,706 ft
- 6S9 — Stehekin State
Stehekin · elev 1,230 ft
- 2S0 — Twisp Municipal
Twisp · elev 1,602 ft
- KOMK — Omak
Omak · elev 1,305 ft
- S35 — Okanogan Legion
Okanogan · elev 1,042 ft
- W01 — Tonasket Municipal
Tonasket · elev 1,311 ft
- S97 — Anderson Field
Brewster · elev 920 ft
- 0S7 — Dorothy Scott International
Oroville · elev 1,069 ft
Frequently asked questions
How high does density altitude get at W12 in summer?
On a typical July afternoon — around 85 °F at the nearest NOAA normals station — density altitude at Lost River reaches roughly 4,592 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 W12 on an average day?
It swings with the seasons: from roughly 518 ft at the coldest month's average temperature to about 3,670 ft at the warmest month's — all from a constant field elevation of 2,415 ft. The month-by-month table above carries the full year.
What is the field elevation of Lost River?
2,415 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is W12 (FAA), in Mazama, Washington.