East Tawas, Michigan · field elev 605 ft
Density Altitude at Iosco County (6D9)
Iosco County sits at 605 ft, and even a typical July afternoon (80 °F) only lifts density altitude to about 2,120 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 | 21.5 | −1,808 ft | 29.7 | −1,225 ft |
| February | 22.6 | −1,729 ft | 32.3 | −1,042 ft |
| March | 30.9 | −1,140 ft | 40.8 | −454 ft |
| April | 42.2 | −358 ft | 52.2 | 316 ft |
| May | 54.4 | 462 ft | 64.9 | 1,149 ft |
| June | 64.2 | 1,104 ft | 75.2 | 1,806 ft |
| July | 69.2 | 1,425 ft | 80.2 | 2,120 ft |
| August | 67.8 | 1,336 ft | 78.8 | 2,032 ft |
| September | 60.4 | 857 ft | 71.7 | 1,585 ft |
| October | 48.4 | 62 ft | 58.8 | 752 ft |
| November | 37.3 | −695 ft | 45.5 | −134 ft |
| December | 27.8 | −1,359 ft | 35.0 | −854 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 6D9
DENSITY ALTITUDE
Field elevation 605 ft — the air behaves like 2,107 ft.
- PRESSURE ALT
- 606 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 Michigan fields
- KOSC — Oscoda/Wurtsmith
Oscoda · elev 633 ft
- H80 — Field Of Dreams
Hale · elev 830 ft
- 3L7 — Milwrick Flying M
Lincoln · elev 830 ft
- 29C — Grindstone Air Harbor
Port Austin · elev 640 ft
- E53 — Engler Field
Bad Axe · elev 725 ft
- Y31 — West Branch Community
West Branch · elev 882 ft
- 98G — Sebewaing Township
Sebewaing · elev 584 ft
- KBAX — Huron County Meml
Bad Axe · elev 764 ft
Frequently asked questions
How high does density altitude get at 6D9 in summer?
On a typical July afternoon — around 80 °F at the nearest NOAA normals station — density altitude at Iosco County reaches roughly 2,120 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 6D9 on an average day?
It swings with the seasons: from roughly −1,808 ft at the coldest month's average temperature to about 1,425 ft at the warmest month's — all from a constant field elevation of 605 ft. The month-by-month table above carries the full year.
What is the field elevation of Iosco County?
605 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 6D9 (FAA), in East Tawas, Michigan.