Mount Vernon, Ohio · field elev 1,192 ft
Density Altitude at Knox County (4I3)
Knox County sits at 1,192 ft, and even a typical July afternoon (83 °F) only lifts density altitude to about 3,010 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 | 25.2 | −808 ft | 33.5 | −226 ft |
| February | 27.9 | −617 ft | 37.2 | 30 ft |
| March | 37.5 | 50 ft | 47.9 | 756 ft |
| April | 50.0 | 896 ft | 61.8 | 1,671 ft |
| May | 60.3 | 1,574 ft | 71.6 | 2,298 ft |
| June | 68.9 | 2,127 ft | 79.7 | 2,806 ft |
| July | 72.0 | 2,323 ft | 83.0 | 3,010 ft |
| August | 70.4 | 2,222 ft | 81.6 | 2,924 ft |
| September | 63.7 | 1,794 ft | 75.4 | 2,538 ft |
| October | 52.1 | 1,035 ft | 63.5 | 1,781 ft |
| November | 40.6 | 262 ft | 50.1 | 903 ft |
| December | 30.9 | −407 ft | 38.8 | 139 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 4I3
DENSITY ALTITUDE
Field elevation 1,192 ft — the air behaves like 3,010 ft.
- PRESSURE ALT
- 1,193 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 Ohio fields
- 6G4 — Wynkoop
Mount Vernon · elev 1,041 ft
- 6CM — Chapman Meml Field
Centerburg · elev 1,180 ft
- KVTA — Licking County Regional
Newark · elev 884 ft
- 4I9 — Morrow County
Mount Gilead · elev 1,086 ft
- KCMH — John Glenn Columbus International
Columbus · elev 815 ft
- 7B4 — Miller Farm Landing Strip
Baltimore · elev 930 ft
- KDLZ — Delaware Municipal/Jim Moore Field
Delaware · elev 945 ft
- KGQQ — Galion Municipal
Galion · elev 1,224 ft
Frequently asked questions
How high does density altitude get at 4I3 in summer?
On a typical July afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Knox County reaches roughly 3,010 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 4I3 on an average day?
It swings with the seasons: from roughly −808 ft at the coldest month's average temperature to about 2,323 ft at the warmest month's — all from a constant field elevation of 1,192 ft. The month-by-month table above carries the full year.
What is the field elevation of Knox County?
1,192 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4I3 (FAA), in Mount Vernon, Ohio.