Pottstown, Pennsylvania · field elev 308 ft
Density Altitude at Heritage Field (KPTW)
Heritage Field sits at 308 ft, and even a typical July afternoon (84 °F) only lifts density altitude to about 1,981 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 | 29.7 | −1,596 ft | 37.4 | −1,058 ft |
| February | 31.9 | −1,441 ft | 40.4 | −851 ft |
| March | 39.8 | −892 ft | 49.1 | −260 ft |
| April | 50.7 | −152 ft | 61.3 | 549 ft |
| May | 60.4 | 490 ft | 71.0 | 1,176 ft |
| June | 69.1 | 1,054 ft | 79.3 | 1,701 ft |
| July | 74.0 | 1,366 ft | 83.8 | 1,981 ft |
| August | 71.9 | 1,233 ft | 81.5 | 1,838 ft |
| September | 64.7 | 770 ft | 74.6 | 1,405 ft |
| October | 53.3 | 22 ft | 63.3 | 679 ft |
| November | 43.0 | −673 ft | 52.4 | −38 ft |
| December | 34.4 | −1,266 ft | 42.1 | −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 KPTW
DENSITY ALTITUDE
Field elevation 308 ft — the air behaves like 1,993 ft.
- PRESSURE ALT
- 309 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 Pennsylvania fields
- N47 — Pottstown Municipal
Pottstown · elev 256 ft
- 7N8 — Butter Valley Golf Port
Bally · elev 500 ft
- KUKT — Quakertown
Quakertown · elev 525 ft
- KLOM — Wings Field
Philadelphia · elev 302 ft
- KOQN — Brandywine Regional
West Chester · elev 465 ft
- KCKZ — Pennridge
Perkasie · elev 568 ft
- KXLL — Allentown Queen City Municipal
Allentown · elev 399 ft
- KRDG — Reading Regional/Carl A Spaatz Field
Reading · elev 343 ft
Frequently asked questions
How high does density altitude get at KPTW in summer?
On a typical July afternoon — around 84 °F at the nearest NOAA normals station — density altitude at Heritage Field reaches roughly 1,981 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 KPTW on an average day?
It swings with the seasons: from roughly −1,596 ft at the coldest month's average temperature to about 1,366 ft at the warmest month's — all from a constant field elevation of 308 ft. The month-by-month table above carries the full year.
What is the field elevation of Heritage Field?
308 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KPTW (ICAO) / PTW (FAA), in Pottstown, Pennsylvania.