Great Falls, Montana · field elev 3,680 ft
Density Altitude at Great Falls International (KGTF)
From a field elevation of 3,680 ft, a typical July afternoon at Great Falls International (84 °F) raises density altitude to about 6,117 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 | 25.2 | 2,302 ft | 35.3 | 2,993 ft |
| February | 26.2 | 2,371 ft | 37.1 | 3,115 ft |
| March | 34.1 | 2,912 ft | 46.1 | 3,714 ft |
| April | 42.4 | 3,469 ft | 54.9 | 4,287 ft |
| May | 51.5 | 4,067 ft | 64.6 | 4,904 ft |
| June | 59.4 | 4,575 ft | 72.8 | 5,416 ft ▲ |
| July | 67.9 | 5,111 ft | 84.3 | 6,117 ft ▲ |
| August | 66.7 | 5,036 ft | 83.2 | 6,050 ft ▲ |
| September | 57.2 | 4,434 ft | 71.7 | 5,348 ft ▲ |
| October | 44.8 | 3,628 ft | 57.0 | 4,422 ft |
| November | 33.6 | 2,878 ft | 43.7 | 3,555 ft |
| December | 26.0 | 2,357 ft | 35.6 | 3,013 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 KGTF
DENSITY ALTITUDE caution
Field elevation 3,680 ft — the air behaves like 6,099 ft.
- PRESSURE ALT
- 3,682 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
- 5U1 — Dutton
Dutton · elev 3,699 ft
- 5U5 — Fairfield
Fairfield · elev 3,991 ft
- 79S — Fort Benton
Fort Benton · elev 2,869 ft
- KCII — Choteau
Choteau · elev 3,947 ft
- 3U5 — Augusta
Augusta · elev 4,145 ft
- 5U8 — Geraldine
Geraldine · elev 3,185 ft
- S01 — Conrad
Conrad · elev 3,548 ft
- S64 — Stanford/Biggerstaff Field
Stanford · elev 4,328 ft
Frequently asked questions
How high does density altitude get at KGTF in summer?
On a typical July afternoon — around 84 °F at the nearest NOAA normals station — density altitude at Great Falls International reaches roughly 6,117 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 KGTF on an average day?
It swings with the seasons: from roughly 2,302 ft at the coldest month's average temperature to about 5,111 ft at the warmest month's — all from a constant field elevation of 3,680 ft. The month-by-month table above carries the full year.
What is the field elevation of Great Falls International?
3,680 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KGTF (ICAO) / GTF (FAA), in Great Falls, Montana.