Portland-Mulino, Oregon · field elev 260 ft
Density Altitude at Mulino State (4S9)
Mulino State sits at 260 ft, and even a typical August afternoon (83 °F) only lifts density altitude to about 1,891 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 | 42.4 | −774 ft | 48.5 | −359 ft |
| February | 44.7 | −617 ft | 52.5 | −91 ft |
| March | 48.3 | −373 ft | 57.1 | 214 ft |
| April | 52.3 | −105 ft | 62.0 | 536 ft |
| May | 58.7 | 320 ft | 69.2 | 1,001 ft |
| June | 63.4 | 627 ft | 74.5 | 1,339 ft |
| July | 69.6 | 1,027 ft | 83.1 | 1,879 ft |
| August | 69.8 | 1,040 ft | 83.3 | 1,891 ft |
| September | 64.8 | 718 ft | 77.4 | 1,522 ft |
| October | 54.9 | 68 ft | 64.3 | 685 ft |
| November | 46.7 | −481 ft | 53.7 | −11 ft |
| December | 41.8 | −815 ft | 47.6 | −420 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 4S9
DENSITY ALTITUDE
Field elevation 260 ft — the air behaves like 1,873 ft.
- PRESSURE ALT
- 261 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 Oregon fields
- 7S9 — Lenhardt Airpark
Hubbard · elev 165 ft
- KUAO — Aurora State
Aurora · elev 200 ft
- 2S6 — Sportsman Airpark
Newberg · elev 181 ft
- 03S — Sandy River
Sandy · elev 704 ft
- 7S3 — Stark'S Twin Oaks Airpark
Hillsboro · elev 170 ft
- 17S — Chehalem Airpark
Newberg · elev 190 ft
- KTTD — Portland-Troutdale
Portland · elev 39 ft
- KPDX — Portland International
Portland · elev 31 ft
Frequently asked questions
How high does density altitude get at 4S9 in summer?
On a typical August afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Mulino State reaches roughly 1,891 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 4S9 on an average day?
It swings with the seasons: from roughly −815 ft at the coldest month's average temperature to about 1,040 ft at the warmest month's — all from a constant field elevation of 260 ft. The month-by-month table above carries the full year.
What is the field elevation of Mulino State?
260 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4S9 (FAA), in Portland-Mulino, Oregon.