Bois Blanc Island, Michigan · field elev 664 ft
Density Altitude at Bois Blanc Island (6Y1)
Bois Blanc Island sits at 664 ft, and even a typical July afternoon (77 °F) only lifts density altitude to about 2,017 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 | 19.3 | −1,892 ft | 27.2 | −1,327 ft |
| February | 19.7 | −1,863 ft | 29.0 | −1,200 ft |
| March | 27.8 | −1,285 ft | 37.6 | −600 ft |
| April | 39.5 | −470 ft | 49.0 | 175 ft |
| May | 51.5 | 342 ft | 61.8 | 1,021 ft |
| June | 61.9 | 1,027 ft | 72.1 | 1,682 ft |
| July | 67.6 | 1,395 ft | 77.4 | 2,017 ft |
| August | 66.8 | 1,344 ft | 76.6 | 1,967 ft |
| September | 59.5 | 871 ft | 69.5 | 1,517 ft |
| October | 47.6 | 81 ft | 56.3 | 660 ft |
| November | 36.6 | −669 ft | 43.7 | −183 ft |
| December | 26.9 | −1,348 ft | 33.4 | −892 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 6Y1
DENSITY ALTITUDE
Field elevation 664 ft — the air behaves like 1,992 ft.
- PRESSURE ALT
- 665 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
- KSLH — Cheboygan County
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- KMCD — Mackinac Island
Mackinac Island · elev 741 ft
- 83D — Mackinac County
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- Y30 — Pbeaaye
Topinabee · elev 690 ft
- 2M7 — Hoffman'S Black Mountain Aerodrome
Cheboygan · elev 677 ft
- 5Y1 — Albert J Lindberg
Hessel · elev 760 ft
- KPLN — Pellston Regional/Emmet County
Pellston · elev 721 ft
- Y65 — Campbell-Pratt
Indian River · elev 614 ft
Frequently asked questions
How high does density altitude get at 6Y1 in summer?
On a typical July afternoon — around 77 °F at the nearest NOAA normals station — density altitude at Bois Blanc Island reaches roughly 2,017 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 6Y1 on an average day?
It swings with the seasons: from roughly −1,892 ft at the coldest month's average temperature to about 1,395 ft at the warmest month's — all from a constant field elevation of 664 ft. The month-by-month table above carries the full year.
What is the field elevation of Bois Blanc Island?
664 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 6Y1 (FAA), in Bois Blanc Island, Michigan.