Cottage Grove, Oregon · field elev 645 ft
Density Altitude at Cottage Grove State (61S)
Cottage Grove State sits at 645 ft, and even a typical August afternoon (83 °F) only lifts density altitude to about 2,318 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 | −411 ft | 48.1 | 91 ft |
| February | 42.7 | −274 ft | 51.7 | 332 ft |
| March | 45.8 | −64 ft | 56.3 | 637 ft |
| April | 49.7 | 198 ft | 61.1 | 952 ft |
| May | 55.6 | 591 ft | 67.8 | 1,385 ft |
| June | 60.5 | 912 ft | 73.2 | 1,729 ft |
| July | 66.6 | 1,308 ft | 82.0 | 2,281 ft |
| August | 66.5 | 1,301 ft | 82.6 | 2,318 ft |
| September | 61.3 | 965 ft | 76.5 | 1,937 ft |
| October | 52.6 | 392 ft | 64.1 | 1,146 ft |
| November | 45.0 | −118 ft | 53.0 | 419 ft |
| December | 40.0 | −459 ft | 46.7 | −3 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 61S
DENSITY ALTITUDE
Field elevation 645 ft — the air behaves like 2,343 ft.
- PRESSURE ALT
- 646 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
- 77S — Hobby Field
Creswell · elev 541 ft
- KEUG — Mahlon Sweet Field
Eugene · elev 374 ft
- 5S0 — Oakridge State
Oakridge · elev 1,393 ft
- KRBG — Roseburg Regional
Roseburg · elev 533 ft
- 5S1 — George Felt
Roseburg · elev 428 ft
- KCVO — Corvallis Municipal
Corvallis · elev 250 ft
- 3S6 — Toketee State
Clearwater · elev 3,361 ft
- S30 — Lebanon State
Lebanon · elev 349 ft
Frequently asked questions
How high does density altitude get at 61S in summer?
On a typical August afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Cottage Grove State reaches roughly 2,318 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 61S on an average day?
It swings with the seasons: from roughly −459 ft at the coldest month's average temperature to about 1,308 ft at the warmest month's — all from a constant field elevation of 645 ft. The month-by-month table above carries the full year.
What is the field elevation of Cottage Grove State?
645 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 61S (FAA), in Cottage Grove, Oregon.