Thompson Falls, Montana · field elev 2,467 ft
Density Altitude at Thompson Falls (KTHM)
Thompson Falls sits at 2,467 ft, and even a typical July afternoon (86 °F) only lifts density altitude to about 4,770 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 | 29.1 | 1,059 ft | 34.0 | 1,397 ft |
| February | 32.3 | 1,280 ft | 39.8 | 1,792 ft |
| March | 39.4 | 1,765 ft | 49.4 | 2,433 ft |
| April | 46.3 | 2,227 ft | 58.2 | 3,007 ft |
| May | 54.9 | 2,793 ft | 68.4 | 3,658 ft |
| June | 61.1 | 3,194 ft | 74.5 | 4,040 ft |
| July | 69.5 | 3,728 ft | 86.4 | 4,770 ft |
| August | 68.8 | 3,683 ft | 86.2 | 4,758 ft |
| September | 59.8 | 3,110 ft | 75.4 | 4,096 ft |
| October | 46.9 | 2,267 ft | 58.0 | 2,994 ft |
| November | 35.3 | 1,486 ft | 41.3 | 1,893 ft |
| December | 28.7 | 1,032 ft | 32.9 | 1,322 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 KTHM
DENSITY ALTITUDE
Field elevation 2,467 ft — the air behaves like 4,746 ft.
- PRESSURE ALT
- 2,469 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
- S34 — Plains
Plains · elev 2,467 ft
- S09 — Hot Springs
Hot Springs · elev 2,763 ft
- 9S4 — Mineral County
Superior · elev 2,787 ft
- S59 — Libby
Libby · elev 2,605 ft
- 8S1 — Polson
Polson · elev 2,941 ft
- 7S0 — Ronan
Ronan · elev 3,086 ft
- 52S — St Ignatius
St Ignatius · elev 3,006 ft
- S27 — Kalispell City
Kalispell · elev 2,932 ft
Frequently asked questions
How high does density altitude get at KTHM in summer?
On a typical July afternoon — around 86 °F at the nearest NOAA normals station — density altitude at Thompson Falls reaches roughly 4,770 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 KTHM on an average day?
It swings with the seasons: from roughly 1,032 ft at the coldest month's average temperature to about 3,728 ft at the warmest month's — all from a constant field elevation of 2,467 ft. The month-by-month table above carries the full year.
What is the field elevation of Thompson Falls?
2,467 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KTHM (ICAO) / THM (FAA), in Thompson Falls, Montana.