Rochester, Washington · field elev 149 ft
Density Altitude at R & K Skyranch (8W9)
R & K Skyranch sits at 149 ft, and even a typical August afternoon (78 °F) only lifts density altitude to about 1,437 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 | 40.2 | −1,063 ft | 46.1 | −660 ft |
| February | 41.7 | −960 ft | 49.5 | −430 ft |
| March | 45.0 | −734 ft | 54.1 | −122 ft |
| April | 49.3 | −443 ft | 59.5 | 235 ft |
| May | 55.5 | −29 ft | 66.6 | 698 ft |
| June | 60.1 | 274 ft | 71.1 | 987 ft |
| July | 65.2 | 607 ft | 77.5 | 1,393 ft |
| August | 65.5 | 626 ft | 78.2 | 1,437 ft |
| September | 60.5 | 301 ft | 72.6 | 1,082 ft |
| October | 51.9 | −269 ft | 61.1 | 340 ft |
| November | 43.9 | −809 ft | 50.7 | −349 ft |
| December | 39.4 | −1,118 ft | 45.0 | −734 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 8W9
DENSITY ALTITUDE
Field elevation 149 ft — the air behaves like 1,424 ft.
- PRESSURE ALT
- 150 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
- KCLS — Chehalis-Centralia
Chehalis · elev 177 ft
- KOLM — Olympia Regional
Olympia · elev 208 ft
- 44T — Hoskins Field
Olympia · elev 213 ft
- KSHN — Sanderson Field
Shelton · elev 273 ft
- KTDO — Ed Carlson Meml Field/South Lewis County
Toledo · elev 374 ft
- 2S9 — Willapa Harbor
South Bend/Raymond/ · elev 13 ft
- 3B8 — Shady Acres
Spanaway · elev 445 ft
- KTIW — Tacoma Narrows
Tacoma · elev 295 ft
Frequently asked questions
How high does density altitude get at 8W9 in summer?
On a typical August afternoon — around 78 °F at the nearest NOAA normals station — density altitude at R & K Skyranch reaches roughly 1,437 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 8W9 on an average day?
It swings with the seasons: from roughly −1,118 ft at the coldest month's average temperature to about 626 ft at the warmest month's — all from a constant field elevation of 149 ft. The month-by-month table above carries the full year.
What is the field elevation of R & K Skyranch?
149 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 8W9 (FAA), in Rochester, Washington.