Sweetgrass, Montana · field elev 3,553 ft
Density Altitude at Ross International (7S8)
From a field elevation of 3,553 ft, a typical July afternoon at Ross International (82 °F) raises density altitude to about 5,848 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 | 21.3 | 1,871 ft | 32.2 | 2,625 ft |
| February | 23.7 | 2,039 ft | 35.4 | 2,842 ft |
| March | 32.3 | 2,632 ft | 43.8 | 3,405 ft |
| April | 42.0 | 3,285 ft | 54.6 | 4,111 ft |
| May | 52.5 | 3,975 ft | 66.0 | 4,837 ft |
| June | 60.0 | 4,457 ft | 73.0 | 5,273 ft ▲ |
| July | 67.7 | 4,944 ft | 82.4 | 5,848 ft ▲ |
| August | 66.6 | 4,875 ft | 82.0 | 5,824 ft ▲ |
| September | 57.1 | 4,272 ft | 71.8 | 5,199 ft ▲ |
| October | 44.5 | 3,451 ft | 57.2 | 4,278 ft |
| November | 31.8 | 2,598 ft | 42.6 | 3,325 ft |
| December | 22.1 | 1,927 ft | 32.5 | 2,645 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 7S8
DENSITY ALTITUDE caution
Field elevation 3,553 ft — the air behaves like 5,824 ft.
- PRESSURE ALT
- 3,555 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
- KSBX — Shelby
Shelby · elev 3,443 ft
- KCTB — Cut Bank International
Cut Bank · elev 3,858 ft
- H28 — Whetstone International
Port Of Del Bonita · elev 4,336 ft
- 7S7 — Valier
Valier · elev 3,826 ft
- KLTY — Liberty County
Chester · elev 3,185 ft
- S01 — Conrad
Conrad · elev 3,548 ft
- 8S0 — Starr-Browning Airstrip
Browning · elev 4,657 ft
- B70 — Tiber Dam
Tiber Dam · elev 3,023 ft
Frequently asked questions
How high does density altitude get at 7S8 in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Ross International reaches roughly 5,848 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 7S8 on an average day?
It swings with the seasons: from roughly 1,871 ft at the coldest month's average temperature to about 4,944 ft at the warmest month's — all from a constant field elevation of 3,553 ft. The month-by-month table above carries the full year.
What is the field elevation of Ross International?
3,553 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 7S8 (FAA), in Sweetgrass, Montana.