Circle, Montana · field elev 2,441 ft
Density Altitude at Circle Town County (4U6)
Circle Town County sits at 2,441 ft, and even a typical July afternoon (87 °F) only lifts density altitude to about 4,781 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 | 18.1 | 253 ft | 28.5 | 985 ft |
| February | 22.1 | 537 ft | 32.6 | 1,269 ft |
| March | 33.6 | 1,337 ft | 45.5 | 2,142 ft |
| April | 44.9 | 2,102 ft | 58.1 | 2,969 ft |
| May | 55.0 | 2,768 ft | 68.3 | 3,620 ft |
| June | 64.3 | 3,367 ft | 77.7 | 4,207 ft |
| July | 72.1 | 3,859 ft | 87.1 | 4,781 ft |
| August | 71.1 | 3,796 ft | 86.8 | 4,763 ft |
| September | 60.3 | 3,111 ft | 75.5 | 4,071 ft |
| October | 46.0 | 2,175 ft | 58.8 | 3,014 ft |
| November | 32.0 | 1,227 ft | 42.8 | 1,962 ft |
| December | 21.3 | 480 ft | 31.5 | 1,193 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 4U6
DENSITY ALTITUDE
Field elevation 2,441 ft — the air behaves like 4,775 ft.
- PRESSURE ALT
- 2,442 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
- 7U8 — Richey
Richey · elev 2,494 ft
- KGDV — Dawson Community
Glendive · elev 2,458 ft
- 8U6 — Terry
Terry · elev 2,283 ft
- KOLF — L M Clayton
Wolf Point · elev 1,989 ft
- PO1 — Poplar Municipal
Poplar · elev 2,037 ft
- 37S — Fort Peck
Fort Peck · elev 2,290 ft
- KJDN — Jordan
Jordan · elev 2,667 ft
- KSDY — Sidney-Richland Regional
Sidney · elev 1,985 ft
Frequently asked questions
How high does density altitude get at 4U6 in summer?
On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Circle Town County reaches roughly 4,781 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 4U6 on an average day?
It swings with the seasons: from roughly 253 ft at the coldest month's average temperature to about 3,859 ft at the warmest month's — all from a constant field elevation of 2,441 ft. The month-by-month table above carries the full year.
What is the field elevation of Circle Town County?
2,441 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4U6 (FAA), in Circle, Montana.