Cornelius, Oregon · field elev 174 ft
Density Altitude at Skyport (4S4)
Skyport sits at 174 ft, and even a typical August afternoon (82 °F) only lifts density altitude to about 1,718 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 | 38.8 | −1,128 ft | 45.0 | −703 ft |
| February | 41.2 | −963 ft | 49.4 | −406 ft |
| March | 45.2 | −690 ft | 54.6 | −58 ft |
| April | 49.6 | −392 ft | 60.1 | 305 ft |
| May | 56.7 | 81 ft | 68.1 | 825 ft |
| June | 61.4 | 390 ft | 73.1 | 1,145 ft |
| July | 67.6 | 793 ft | 81.4 | 1,668 ft |
| August | 67.9 | 812 ft | 82.2 | 1,718 ft |
| September | 62.4 | 456 ft | 76.1 | 1,335 ft |
| October | 52.4 | −204 ft | 63.3 | 514 ft |
| November | 43.6 | −799 ft | 50.9 | −305 ft |
| December | 38.4 | −1,156 ft | 44.0 | −771 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 4S4
DENSITY ALTITUDE
Field elevation 174 ft — the air behaves like 1,705 ft.
- PRESSURE ALT
- 175 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
- KHIO — Portland-Hillsboro
Portland · elev 208 ft
- 7S3 — Stark'S Twin Oaks Airpark
Hillsboro · elev 170 ft
- KSPB — Scappoose
Scappoose · elev 58 ft
- 17S — Chehalem Airpark
Newberg · elev 190 ft
- 2S6 — Sportsman Airpark
Newberg · elev 181 ft
- 05S — Vernonia Municipal
Vernonia · elev 650 ft
- KPDX — Portland International
Portland · elev 31 ft
- KUAO — Aurora State
Aurora · elev 200 ft
Frequently asked questions
How high does density altitude get at 4S4 in summer?
On a typical August afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Skyport reaches roughly 1,718 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 4S4 on an average day?
It swings with the seasons: from roughly −1,156 ft at the coldest month's average temperature to about 812 ft at the warmest month's — all from a constant field elevation of 174 ft. The month-by-month table above carries the full year.
What is the field elevation of Skyport?
174 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4S4 (FAA), in Cornelius, Oregon.