Harrisburg, Illinois · field elev 398 ft
Density Altitude at Harrisburg-Raleigh (KHSB)
Harrisburg-Raleigh sits at 398 ft, and even a typical July afternoon (89 °F) only lifts density altitude to about 2,417 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 | 33.4 | −1,224 ft | 42.9 | −568 ft |
| February | 38.0 | −904 ft | 47.7 | −242 ft |
| March | 47.1 | −283 ft | 58.1 | 450 ft |
| April | 57.6 | 418 ft | 69.4 | 1,184 ft |
| May | 67.3 | 1,049 ft | 78.2 | 1,742 ft |
| June | 75.5 | 1,572 ft | 86.0 | 2,227 ft |
| July | 78.7 | 1,773 ft | 89.1 | 2,417 ft |
| August | 76.9 | 1,660 ft | 88.2 | 2,362 ft |
| September | 69.8 | 1,209 ft | 82.4 | 2,004 ft |
| October | 58.3 | 464 ft | 71.2 | 1,299 ft |
| November | 46.8 | −303 ft | 57.4 | 404 ft |
| December | 37.8 | −918 ft | 46.8 | −303 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 KHSB
DENSITY ALTITUDE
Field elevation 398 ft — the air behaves like 2,411 ft.
- PRESSURE ALT
- 399 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 Illinois fields
- H96 — Benton Municipal
Benton · elev 444 ft
- KMWA — Veterans Airport Of Southern Illinois
Marion · elev 472 ft
- KCUL — Carmi Municipal
Carmi · elev 388 ft
- KMDH — Southern Illinois
Carbondale/Murphysboro · elev 411 ft
- KMVN — Mount Vernon
Mount Vernon · elev 480 ft
- KFWC — Fairfield Municipal
Fairfield · elev 434 ft
- M30 — Metropolis Municipal
Metropolis · elev 384 ft
- KPJY — Pinckneyville/Du Quoin
Pinckneyville · elev 400 ft
Frequently asked questions
How high does density altitude get at KHSB in summer?
On a typical July afternoon — around 89 °F at the nearest NOAA normals station — density altitude at Harrisburg-Raleigh reaches roughly 2,417 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 KHSB on an average day?
It swings with the seasons: from roughly −1,224 ft at the coldest month's average temperature to about 1,773 ft at the warmest month's — all from a constant field elevation of 398 ft. The month-by-month table above carries the full year.
What is the field elevation of Harrisburg-Raleigh?
398 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KHSB (ICAO) / HSB (FAA), in Harrisburg, Illinois.