Sidney, Montana · field elev 1,985 ft
Density Altitude at Sidney-Richland Regional (KSDY)
Sidney-Richland Regional sits at 1,985 ft, and even a typical July afternoon (87 °F) only lifts density altitude to about 4,196 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 | 16.9 | −405 ft | 27.2 | 325 ft |
| February | 21.3 | −91 ft | 32.0 | 659 ft |
| March | 33.4 | 756 ft | 45.8 | 1,597 ft |
| April | 46.1 | 1,617 ft | 60.5 | 2,563 ft |
| May | 57.0 | 2,336 ft | 71.3 | 3,251 ft |
| June | 65.7 | 2,896 ft | 79.1 | 3,737 ft |
| July | 72.0 | 3,295 ft | 86.6 | 4,196 ft |
| August | 70.8 | 3,219 ft | 86.4 | 4,184 ft |
| September | 60.6 | 2,569 ft | 75.8 | 3,532 ft |
| October | 46.5 | 1,644 ft | 59.4 | 2,492 ft |
| November | 31.6 | 631 ft | 41.9 | 1,336 ft |
| December | 20.6 | −141 ft | 30.6 | 562 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 KSDY
DENSITY ALTITUDE
Field elevation 1,985 ft — the air behaves like 4,221 ft.
- PRESSURE ALT
- 1,986 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
- 5U6 — Fairview
Fairview · elev 2,152 ft
- S85 — Big Sky Field
Culbertson · elev 1,953 ft
- 7U8 — Richey
Richey · elev 2,494 ft
- KGDV — Dawson Community
Glendive · elev 2,458 ft
- PO1 — Poplar Municipal
Poplar · elev 2,037 ft
- 4U6 — Circle Town County
Circle · elev 2,441 ft
- KOLF — L M Clayton
Wolf Point · elev 1,989 ft
- KPWD — Sher-Wood
Plentywood · elev 2,264 ft
Frequently asked questions
How high does density altitude get at KSDY in summer?
On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Sidney-Richland Regional reaches roughly 4,196 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 KSDY on an average day?
It swings with the seasons: from roughly −405 ft at the coldest month's average temperature to about 3,295 ft at the warmest month's — all from a constant field elevation of 1,985 ft. The month-by-month table above carries the full year.
What is the field elevation of Sidney-Richland Regional?
1,985 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KSDY (ICAO) / SDY (FAA), in Sidney, Montana.