Creswell, Oregon · field elev 541 ft
Density Altitude at Hobby Field (77S)
Hobby Field sits at 541 ft, and even a typical August afternoon (83 °F) only lifts density altitude to about 2,191 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 | 40.7 | −540 ft | 48.1 | −38 ft |
| February | 42.7 | −404 ft | 51.7 | 203 ft |
| March | 45.8 | −193 ft | 56.3 | 508 ft |
| April | 49.7 | 70 ft | 61.1 | 823 ft |
| May | 55.6 | 462 ft | 67.8 | 1,257 ft |
| June | 60.5 | 784 ft | 73.2 | 1,601 ft |
| July | 66.6 | 1,180 ft | 82.0 | 2,154 ft |
| August | 66.5 | 1,173 ft | 82.6 | 2,191 ft |
| September | 61.3 | 836 ft | 76.5 | 1,810 ft |
| October | 52.6 | 263 ft | 64.1 | 1,018 ft |
| November | 45.0 | −247 ft | 53.0 | 290 ft |
| December | 40.0 | −588 ft | 46.7 | −132 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 77S
DENSITY ALTITUDE
Field elevation 541 ft — the air behaves like 2,216 ft.
- PRESSURE ALT
- 542 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
- 61S — Cottage Grove State
Cottage Grove · elev 645 ft
- KEUG — Mahlon Sweet Field
Eugene · elev 374 ft
- 5S0 — Oakridge State
Oakridge · elev 1,393 ft
- KCVO — Corvallis Municipal
Corvallis · elev 250 ft
- S30 — Lebanon State
Lebanon · elev 349 ft
- S12 — Albany Municipal
Albany · elev 227 ft
- 00S — Mc Kenzie Bridge State
Mc Kenzie Bridge · elev 1,620 ft
- KRBG — Roseburg Regional
Roseburg · elev 533 ft
Frequently asked questions
How high does density altitude get at 77S in summer?
On a typical August afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Hobby Field reaches roughly 2,191 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 77S on an average day?
It swings with the seasons: from roughly −588 ft at the coldest month's average temperature to about 1,180 ft at the warmest month's — all from a constant field elevation of 541 ft. The month-by-month table above carries the full year.
What is the field elevation of Hobby Field?
541 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 77S (FAA), in Creswell, Oregon.