Prosser, Washington · field elev 706 ft
Density Altitude at Prosser (S40)
Prosser sits at 706 ft, and even a typical July afternoon (90 °F) only lifts density altitude to about 2,872 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 | 33.5 | −832 ft | 40.1 | −376 ft |
| February | 37.6 | −548 ft | 46.7 | 72 ft |
| March | 45.4 | −15 ft | 55.9 | 686 ft |
| April | 52.2 | 441 ft | 64.6 | 1,254 ft |
| May | 61.0 | 1,020 ft | 74.1 | 1,861 ft |
| June | 67.2 | 1,421 ft | 80.9 | 2,287 ft |
| July | 75.0 | 1,917 ft | 90.4 | 2,872 ft |
| August | 73.4 | 1,816 ft | 89.2 | 2,798 ft |
| September | 64.9 | 1,273 ft | 79.7 | 2,212 ft |
| October | 52.8 | 481 ft | 64.7 | 1,260 ft |
| November | 40.5 | −349 ft | 49.3 | 247 ft |
| December | 32.9 | −874 ft | 39.5 | −417 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 S40
DENSITY ALTITUDE
Field elevation 706 ft — the air behaves like 2,847 ft.
- PRESSURE ALT
- 707 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
- 1S5 — Sunnyside Municipal
Sunnyside · elev 768 ft
- KRLD — Richland
Richland · elev 394 ft
- KPSC — Tri-Cities
Pasco · elev 410 ft
- M94 — Desert Aire Regional
Mattawa · elev 586 ft
- KYKM — Yakima Air Trml/Mcallister Field
Yakima · elev 1,099 ft
- S70 — Othello Municipal
Othello · elev 1,149 ft
- S20 — Goldendale
Goldendale · elev 1,678 ft
- 2S4 — Warden
Warden · elev 1,276 ft
Frequently asked questions
How high does density altitude get at S40 in summer?
On a typical July afternoon — around 90 °F at the nearest NOAA normals station — density altitude at Prosser reaches roughly 2,872 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 S40 on an average day?
It swings with the seasons: from roughly −874 ft at the coldest month's average temperature to about 1,917 ft at the warmest month's — all from a constant field elevation of 706 ft. The month-by-month table above carries the full year.
What is the field elevation of Prosser?
706 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is S40 (FAA), in Prosser, Washington.