Vashon, Washington · field elev 316 ft
Density Altitude at Vashon Municipal (2S1)
Vashon Municipal sits at 316 ft, and even a typical August afternoon (78 °F) only lifts density altitude to about 1,604 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 | 42.8 | −677 ft | 48.0 | −324 ft |
| February | 44.0 | −595 ft | 50.3 | −169 ft |
| March | 47.1 | −384 ft | 54.2 | 91 ft |
| April | 51.3 | −102 ft | 59.3 | 428 ft |
| May | 57.5 | 310 ft | 66.3 | 884 ft |
| June | 62.0 | 605 ft | 71.1 | 1,192 ft |
| July | 67.1 | 935 ft | 77.4 | 1,591 ft |
| August | 67.4 | 955 ft | 77.6 | 1,604 ft |
| September | 62.6 | 644 ft | 71.6 | 1,224 ft |
| October | 53.8 | 65 ft | 60.5 | 507 ft |
| November | 46.5 | −425 ft | 52.1 | −49 ft |
| December | 42.0 | −731 ft | 47.0 | −391 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 2S1
DENSITY ALTITUDE
Field elevation 316 ft — the air behaves like 1,629 ft.
- PRESSURE ALT
- 317 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
- KSEA — Seattle-Tacoma International
Seattle · elev 432 ft
- KBFI — Boeing Field/King County International
Seattle · elev 22 ft
- KRNT — Renton Municipal
Renton · elev 32 ft
- KPWT — Bremerton Ntl
Bremerton · elev 444 ft
- KTIW — Tacoma Narrows
Tacoma · elev 295 ft
- S50 — Auburn Municipal
Auburn · elev 63 ft
- 8W5 — Apex Airpark
Silverdale · elev 525 ft
- S36 — Crest Airfield
Covington · elev 472 ft
Frequently asked questions
How high does density altitude get at 2S1 in summer?
On a typical August afternoon — around 78 °F at the nearest NOAA normals station — density altitude at Vashon Municipal reaches roughly 1,604 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 2S1 on an average day?
It swings with the seasons: from roughly −731 ft at the coldest month's average temperature to about 955 ft at the warmest month's — all from a constant field elevation of 316 ft. The month-by-month table above carries the full year.
What is the field elevation of Vashon Municipal?
316 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 2S1 (FAA), in Vashon, Washington.