Empire, Michigan · field elev 944 ft
Density Altitude at William B Bolton (Y87)
William B Bolton sits at 944 ft, and even a typical July afternoon (80 °F) only lifts density altitude to about 2,516 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 | 22.3 | −1,325 ft | 28.7 | −871 ft |
| February | 23.3 | −1,254 ft | 31.0 | −710 ft |
| March | 31.2 | −696 ft | 40.8 | −32 ft |
| April | 42.0 | 50 ft | 52.9 | 782 ft |
| May | 54.2 | 868 ft | 66.8 | 1,688 ft |
| June | 63.6 | 1,482 ft | 75.6 | 2,247 ft |
| July | 68.6 | 1,803 ft | 79.9 | 2,516 ft |
| August | 67.6 | 1,739 ft | 78.3 | 2,416 ft |
| September | 60.6 | 1,287 ft | 71.0 | 1,956 ft |
| October | 49.2 | 535 ft | 58.3 | 1,137 ft |
| November | 37.5 | −258 ft | 44.7 | 233 ft |
| December | 28.2 | −906 ft | 34.1 | −493 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 Y87
DENSITY ALTITUDE
Field elevation 944 ft — the air behaves like 2,522 ft.
- PRESSURE ALT
- 945 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
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- Y88 — Green Lake
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- 7Y2 — Thompsonville
Thompsonville · elev 793 ft
- KTVC — Cherry Capital
Traverse City · elev 624 ft
- 5D5 — Woolsey Meml
Northport · elev 628 ft
- 4Y9 — Eagles Landing
Harrietta · elev 993 ft
- 59M — Torchport
Eastport · elev 640 ft
Frequently asked questions
How high does density altitude get at Y87 in summer?
On a typical July afternoon — around 80 °F at the nearest NOAA normals station — density altitude at William B Bolton reaches roughly 2,516 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 Y87 on an average day?
It swings with the seasons: from roughly −1,325 ft at the coldest month's average temperature to about 1,803 ft at the warmest month's — all from a constant field elevation of 944 ft. The month-by-month table above carries the full year.
What is the field elevation of William B Bolton?
944 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is Y87 (FAA), in Empire, Michigan.