Harlem, Montana · field elev 2,643 ft
Density Altitude at Harlem (48S)
Harlem sits at 2,643 ft, and even a typical July afternoon (85 °F) only lifts density altitude to about 4,899 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 | 16.6 | 399 ft | 28.2 | 1,216 ft |
| February | 20.8 | 698 ft | 32.7 | 1,527 ft |
| March | 32.5 | 1,513 ft | 45.0 | 2,359 ft |
| April | 44.4 | 2,319 ft | 58.8 | 3,262 ft |
| May | 54.3 | 2,971 ft | 69.0 | 3,912 ft |
| June | 62.6 | 3,506 ft | 76.6 | 4,385 ft |
| July | 69.3 | 3,930 ft | 85.0 | 4,899 ft |
| August | 68.2 | 3,861 ft | 84.7 | 4,881 ft |
| September | 57.9 | 3,204 ft | 74.1 | 4,230 ft |
| October | 45.1 | 2,365 ft | 59.7 | 3,320 ft |
| November | 31.1 | 1,417 ft | 43.3 | 2,245 ft |
| December | 19.8 | 627 ft | 30.9 | 1,403 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 48S
DENSITY ALTITUDE
Field elevation 2,643 ft — the air behaves like 4,899 ft.
- PRESSURE ALT
- 2,645 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
- 6U6 — Hogeland
Hogeland · elev 3,139 ft
- S71 — Edgar G Obie
Chinook · elev 2,416 ft
- 9U0 — Turner
Turner · elev 3,051 ft
- M75 — Malta
Malta · elev 2,254 ft
- CW0 — Cow Creek
Winifred · elev 3,300 ft
- KHVR — Havre City-County
Havre · elev 2,591 ft
- LC0 — Left Coulee
Winifred · elev 3,150 ft
- BW8 — Bullwhacker
Winifred · elev 3,100 ft
Frequently asked questions
How high does density altitude get at 48S in summer?
On a typical July afternoon — around 85 °F at the nearest NOAA normals station — density altitude at Harlem reaches roughly 4,899 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 48S on an average day?
It swings with the seasons: from roughly 399 ft at the coldest month's average temperature to about 3,930 ft at the warmest month's — all from a constant field elevation of 2,643 ft. The month-by-month table above carries the full year.
What is the field elevation of Harlem?
2,643 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 48S (FAA), in Harlem, Montana.