Townsend, Montana · field elev 3,840 ft
Density Altitude at Canyon Ferry (8U9)
From a field elevation of 3,840 ft, a typical July afternoon at Canyon Ferry (83 °F) raises density altitude to about 6,257 ft — solidly into the range where performance charts deserve a close read.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 23.8 | 2,404 ft | 33.9 | 3,097 ft |
| February | 27.6 | 2,667 ft | 38.7 | 3,420 ft |
| March | 36.5 | 3,273 ft | 49.4 | 4,127 ft |
| April | 44.6 | 3,812 ft | 58.2 | 4,695 ft |
| May | 53.2 | 4,374 ft | 67.0 | 5,251 ft ▲ |
| June | 60.4 | 4,835 ft | 74.1 | 5,691 ft ▲ |
| July | 67.5 | 5,282 ft | 83.4 | 6,257 ft ▲ |
| August | 66.2 | 5,201 ft | 82.6 | 6,209 ft ▲ |
| September | 57.2 | 4,631 ft | 72.7 | 5,605 ft ▲ |
| October | 45.2 | 3,852 ft | 58.5 | 4,714 ft |
| November | 33.0 | 3,036 ft | 43.7 | 3,753 ft |
| December | 24.0 | 2,418 ft | 33.8 | 3,090 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 8U9
DENSITY ALTITUDE caution
Field elevation 3,840 ft — the air behaves like 6,233 ft.
- PRESSURE ALT
- 3,842 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 Montana fields
- 8U8 — Townsend
Townsend · elev 3,897 ft
- KHLN — Helena Regional
Helena · elev 3,877 ft
- 3U9 — Boulder
Boulder · elev 4,968 ft
- 7S6 — White Sulphur Springs
White Sulphur Springs · elev 5,065 ft
- 9S5 — Three Forks
Three Forks · elev 4,089 ft
- KBZN — Bozeman Yellowstone International
Bozeman · elev 4,473 ft
- 9U1 — Wilsall
Wilsall · elev 5,140 ft
- KBTM — Bert Mooney
Butte · elev 5,551 ft
Frequently asked questions
How high does density altitude get at 8U9 in summer?
On a typical July afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Canyon Ferry reaches roughly 6,257 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 8U9 on an average day?
It swings with the seasons: from roughly 2,404 ft at the coldest month's average temperature to about 5,282 ft at the warmest month's — all from a constant field elevation of 3,840 ft. The month-by-month table above carries the full year.
What is the field elevation of Canyon Ferry?
3,840 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 8U9 (FAA), in Townsend, Montana.