Belle Fourche, South Dakota · field elev 3,191 ft
Density Altitude at Belle Fourche Municipal (KEFC)
From a field elevation of 3,191 ft, a typical July afternoon at Belle Fourche Municipal (87 °F) raises density altitude to about 5,703 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 | 24.7 | 1,657 ft | 36.5 | 2,467 ft |
| February | 27.1 | 1,824 ft | 39.1 | 2,643 ft |
| March | 36.8 | 2,488 ft | 49.7 | 3,346 ft |
| April | 45.9 | 3,096 ft | 59.0 | 3,949 ft |
| May | 56.0 | 3,756 ft | 68.5 | 4,551 ft |
| June | 66.5 | 4,425 ft | 79.3 | 5,219 ft ▲ |
| July | 73.5 | 4,862 ft | 87.3 | 5,703 ft ▲ |
| August | 71.7 | 4,751 ft | 86.6 | 5,661 ft ▲ |
| September | 62.2 | 4,153 ft | 77.8 | 5,127 ft ▲ |
| October | 48.6 | 3,274 ft | 62.2 | 4,153 ft |
| November | 35.6 | 2,406 ft | 47.5 | 3,202 ft |
| December | 26.0 | 1,747 ft | 37.1 | 2,508 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 KEFC
DENSITY ALTITUDE caution
Field elevation 3,191 ft — the air behaves like 5,685 ft.
- PRESSURE ALT
- 3,193 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 South Dakota fields
- KSPF — Black Hills-Clyde Ice Field
Spearfish · elev 3,933 ft
- 49B — Sturgis Municipal
Sturgis · elev 3,255 ft
- 9D2 — Harding County
Buffalo · elev 2,891 ft
- KRAP — Rapid City Regional
Rapid City · elev 3,204 ft
- KCUT — Custer County
Custer · elev 5,620 ft
- 6V5 — Bison Municipal
Bison · elev 2,791 ft
- D07 — Faith Municipal
Faith · elev 2,584 ft
- 6V4 — Wall Municipal
Wall · elev 2,813 ft
Frequently asked questions
How high does density altitude get at KEFC in summer?
On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Belle Fourche Municipal reaches roughly 5,703 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 KEFC on an average day?
It swings with the seasons: from roughly 1,657 ft at the coldest month's average temperature to about 4,862 ft at the warmest month's — all from a constant field elevation of 3,191 ft. The month-by-month table above carries the full year.
What is the field elevation of Belle Fourche Municipal?
3,191 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KEFC (ICAO) / EFC (FAA), in Belle Fourche, South Dakota.