Augusta, Montana · field elev 5,434 ft
Density Altitude at Benchmark (3U7)
From a field elevation of 5,434 ft, a typical July afternoon at Benchmark (79 °F) raises density altitude to about 7,897 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 | 24.0 | 4,404 ft | 35.6 | 5,187 ft ▲ |
| February | 24.1 | 4,411 ft | 36.0 | 5,214 ft ▲ |
| March | 30.5 | 4,846 ft | 42.5 | 5,642 ft ▲ |
| April | 37.6 | 5,320 ft | 49.8 | 6,115 ft ▲ |
| May | 45.9 | 5,863 ft | 59.1 | 6,706 ft ▲ |
| June | 53.3 | 6,339 ft | 67.2 | 7,210 ft ▲ |
| July | 61.6 | 6,862 ft | 78.5 | 7,897 ft ▲ |
| August | 60.4 | 6,787 ft | 78.0 | 7,867 ft ▲ |
| September | 51.9 | 6,250 ft | 67.5 | 7,228 ft ▲ |
| October | 41.2 | 5,557 ft | 53.9 | 6,377 ft ▲ |
| November | 31.2 | 4,893 ft | 42.0 | 5,609 ft ▲ |
| December | 23.9 | 4,397 ft | 34.5 | 5,114 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 3U7
DENSITY ALTITUDE caution
Field elevation 5,434 ft — the air behaves like 7,927 ft.
- PRESSURE ALT
- 5,436 ft
- ISA DEVIATION
- —
- RULE-OF-THUMB DA
- —
- AIR DENSITY INDEX
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- 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
- 3U5 — Augusta
Augusta · elev 4,145 ft
- 23S — Seeley Lake
Seeley Lake · elev 4,256 ft
- 0S1 — Meadow Creek Usfs
Meadow Creek · elev 3,993 ft
- S69 — Lincoln
Lincoln · elev 4,603 ft
- S04 — Condon Usfs
Condon · elev 3,686 ft
- KCII — Choteau
Choteau · elev 3,947 ft
- 5U5 — Fairfield
Fairfield · elev 3,991 ft
- 8U2 — Schafer /Usfs/
Schafer · elev 4,856 ft
Frequently asked questions
How high does density altitude get at 3U7 in summer?
On a typical July afternoon — around 79 °F at the nearest NOAA normals station — density altitude at Benchmark reaches roughly 7,897 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 3U7 on an average day?
It swings with the seasons: from roughly 4,397 ft at the coldest month's average temperature to about 6,862 ft at the warmest month's — all from a constant field elevation of 5,434 ft. The month-by-month table above carries the full year.
What is the field elevation of Benchmark?
5,434 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 3U7 (FAA), in Augusta, Montana.