Urbana, Ohio · field elev 1,068 ft
Density Altitude at Grimes Field (I74)
Grimes Field sits at 1,068 ft, and even a typical July afternoon (85 °F) only lifts density altitude to about 2,970 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 | 27.2 | −821 ft | 35.4 | −249 ft |
| February | 29.8 | −639 ft | 38.6 | −29 ft |
| March | 38.9 | −8 ft | 48.8 | 662 ft |
| April | 50.2 | 756 ft | 61.8 | 1,518 ft |
| May | 60.9 | 1,460 ft | 72.3 | 2,190 ft |
| June | 70.2 | 2,057 ft | 81.5 | 2,766 ft |
| July | 73.5 | 2,266 ft | 84.8 | 2,970 ft |
| August | 71.9 | 2,165 ft | 83.6 | 2,896 ft |
| September | 65.0 | 1,725 ft | 77.2 | 2,499 ft |
| October | 53.0 | 942 ft | 64.3 | 1,680 ft |
| November | 41.7 | 183 ft | 51.0 | 809 ft |
| December | 32.0 | −485 ft | 39.7 | 47 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 I74
DENSITY ALTITUDE
Field elevation 1,068 ft — the air behaves like 2,982 ft.
- PRESSURE ALT
- 1,069 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
- 38I — Cook
Urbana · elev 1,150 ft
- I54 — Mad River Airpark
Tremont City · elev 958 ft
- KEDJ — Bellefontaine Regional
Bellefontaine · elev 1,122 ft
- KSGH — Springfield/Beckley Municipal
Springfield · elev 1,051 ft
- KUYF — Madison County
London · elev 1,082 ft
- KSCA — Sidney Municipal
Sidney · elev 1,044 ft
- KMRT — Union County
Marysville · elev 1,021 ft
- 1WF — Waco Field
Troy · elev 817 ft
Frequently asked questions
How high does density altitude get at I74 in summer?
On a typical July afternoon — around 85 °F at the nearest NOAA normals station — density altitude at Grimes Field reaches roughly 2,970 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 I74 on an average day?
It swings with the seasons: from roughly −821 ft at the coldest month's average temperature to about 2,266 ft at the warmest month's — all from a constant field elevation of 1,068 ft. The month-by-month table above carries the full year.
What is the field elevation of Grimes Field?
1,068 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is I74 (FAA), in Urbana, Ohio.