Fairfield, Illinois · field elev 434 ft
Density Altitude at Fairfield Municipal (KFWC)
Fairfield Municipal sits at 434 ft, and even a typical July afternoon (90 °F) only lifts density altitude to about 2,492 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 | 32.8 | −1,221 ft | 41.1 | −646 ft |
| February | 37.2 | −915 ft | 46.5 | −279 ft |
| March | 46.6 | −272 ft | 57.0 | 422 ft |
| April | 57.7 | 469 ft | 69.0 | 1,202 ft |
| May | 67.0 | 1,074 ft | 78.1 | 1,779 ft |
| June | 75.6 | 1,622 ft | 86.9 | 2,326 ft |
| July | 78.7 | 1,817 ft | 89.6 | 2,492 ft |
| August | 77.2 | 1,723 ft | 88.8 | 2,443 ft |
| September | 70.2 | 1,279 ft | 82.6 | 2,060 ft |
| October | 58.8 | 541 ft | 70.5 | 1,298 ft |
| November | 46.2 | −299 ft | 56.1 | 363 ft |
| December | 36.9 | −935 ft | 45.0 | −380 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 KFWC
DENSITY ALTITUDE
Field elevation 434 ft — the air behaves like 2,516 ft.
- PRESSURE ALT
- 435 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
- KFOA — Flora Municipal
Flora · elev 473 ft
- KMVN — Mount Vernon
Mount Vernon · elev 480 ft
- KCUL — Carmi Municipal
Carmi · elev 388 ft
- KOLY — Olney-Noble
Olney-Noble · elev 482 ft
- KSLO — Salem-Leckrone
Salem · elev 573 ft
- KENL — Centralia Municipal
Centralia · elev 534 ft
- H96 — Benton Municipal
Benton · elev 444 ft
- KHSB — Harrisburg-Raleigh
Harrisburg · elev 398 ft
Frequently asked questions
How high does density altitude get at KFWC in summer?
On a typical July afternoon — around 90 °F at the nearest NOAA normals station — density altitude at Fairfield Municipal reaches roughly 2,492 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 KFWC on an average day?
It swings with the seasons: from roughly −1,221 ft at the coldest month's average temperature to about 1,817 ft at the warmest month's — all from a constant field elevation of 434 ft. The month-by-month table above carries the full year.
What is the field elevation of Fairfield Municipal?
434 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KFWC (ICAO) / FWC (FAA), in Fairfield, Illinois.