Napa, California · field elev 36 ft
Density Altitude at Napa County (KAPC)
Napa County sits at 36 ft, and even a typical September afternoon (80 °F) only lifts density altitude to about 1,430 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 | 47.6 | −698 ft | 56.9 | −76 ft |
| February | 50.4 | −509 ft | 60.9 | 187 ft |
| March | 53.0 | −335 ft | 64.2 | 403 ft |
| April | 55.8 | −149 ft | 68.1 | 655 ft |
| May | 60.5 | 161 ft | 73.1 | 976 ft |
| June | 65.1 | 461 ft | 78.3 | 1,305 ft |
| July | 66.7 | 565 ft | 78.7 | 1,330 ft |
| August | 67.2 | 597 ft | 80.0 | 1,412 ft |
| September | 65.7 | 500 ft | 80.3 | 1,430 ft |
| October | 60.6 | 168 ft | 75.4 | 1,122 ft |
| November | 52.7 | −355 ft | 65.1 | 461 ft |
| December | 47.5 | −705 ft | 57.3 | −49 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 KAPC
DENSITY ALTITUDE
Field elevation 36 ft — the air behaves like 1,412 ft.
- PRESSURE ALT
- 37 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 California fields
- 0Q9 — Sonoma Skypark
Sonoma · elev 29 ft
- 0Q3 — Sonoma Valley
Schellville/Sonoma · elev 16 ft
- KDVO — Gnoss Field
Novato · elev 4 ft
- O69 — Petaluma Municipal
Petaluma · elev 90 ft
- KCCR — Buchanan Field
Concord · elev 26 ft
- KVCB — Nut Tree
Vacaville · elev 117 ft
- 2O3 — Angwin-Parrett Field
Angwin · elev 1,875 ft
- O88 — Rio Vista Municipal
Rio Vista · elev 23 ft
Frequently asked questions
How high does density altitude get at KAPC in summer?
On a typical September afternoon — around 80 °F at the nearest NOAA normals station — density altitude at Napa County reaches roughly 1,430 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 KAPC on an average day?
It swings with the seasons: from roughly −705 ft at the coldest month's average temperature to about 597 ft at the warmest month's — all from a constant field elevation of 36 ft. The month-by-month table above carries the full year.
What is the field elevation of Napa County?
36 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KAPC (ICAO) / APC (FAA), in Napa, California.