Galesburg, Illinois · field elev 764 ft
Density Altitude at Harrel W Timmons Galesburg Regional (KGBG)
Harrel W Timmons Galesburg Regional sits at 764 ft, and even a typical July afternoon (84 °F) only lifts density altitude to about 2,550 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 | 21.9 | −1,579 ft | 30.0 | −1,005 ft |
| February | 26.0 | −1,287 ft | 34.7 | −676 ft |
| March | 38.0 | −448 ft | 48.0 | 232 ft |
| April | 50.6 | 406 ft | 61.3 | 1,111 ft |
| May | 61.8 | 1,144 ft | 72.0 | 1,799 ft |
| June | 71.6 | 1,773 ft | 81.2 | 2,376 ft |
| July | 74.7 | 1,970 ft | 84.0 | 2,550 ft |
| August | 72.8 | 1,850 ft | 82.3 | 2,445 ft |
| September | 65.5 | 1,383 ft | 76.2 | 2,064 ft |
| October | 52.8 | 552 ft | 63.0 | 1,222 ft |
| November | 39.0 | −379 ft | 48.0 | 232 ft |
| December | 27.8 | −1,160 ft | 35.4 | −628 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 KGBG
DENSITY ALTITUDE
Field elevation 764 ft — the air behaves like 2,550 ft.
- PRESSURE ALT
- 765 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
- C66 — Monmouth Municipal
Monmouth · elev 753 ft
- 2C6 — Tri-County
Yates City · elev 661 ft
- C00 — Mercer County
Aledo · elev 740 ft
- KEZI — Kewanee Municipal
Kewanee · elev 858 ft
- KMQB — Macomb Municipal
Macomb · elev 706 ft
- KCTK — Ingersoll
Canton · elev 684 ft
- KMLI — Quad Cities International
Moline · elev 590 ft
- 3G8 — Gen-Airpark
Geneseo · elev 645 ft
Frequently asked questions
How high does density altitude get at KGBG in summer?
On a typical July afternoon — around 84 °F at the nearest NOAA normals station — density altitude at Harrel W Timmons Galesburg Regional reaches roughly 2,550 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 KGBG on an average day?
It swings with the seasons: from roughly −1,579 ft at the coldest month's average temperature to about 1,970 ft at the warmest month's — all from a constant field elevation of 764 ft. The month-by-month table above carries the full year.
What is the field elevation of Harrel W Timmons Galesburg Regional?
764 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KGBG (ICAO) / GBG (FAA), in Galesburg, Illinois.