Watertown, South Dakota · field elev 1,749 ft
Density Altitude at Watertown Regional (KATY)
Watertown Regional sits at 1,749 ft, and even a typical July afternoon (82 °F) only lifts density altitude to about 3,628 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 | 12.2 | −1,043 ft | 21.4 | −380 ft |
| February | 16.3 | −745 ft | 25.9 | −61 ft |
| March | 29.1 | 163 ft | 38.6 | 819 ft |
| April | 42.8 | 1,103 ft | 54.0 | 1,849 ft |
| May | 55.7 | 1,960 ft | 66.9 | 2,683 ft |
| June | 66.1 | 2,632 ft | 76.8 | 3,306 ft |
| July | 71.0 | 2,943 ft | 82.0 | 3,628 ft |
| August | 68.5 | 2,785 ft | 79.5 | 3,474 ft |
| September | 60.1 | 2,246 ft | 71.6 | 2,981 ft |
| October | 45.7 | 1,298 ft | 56.2 | 1,993 ft |
| November | 30.6 | 268 ft | 39.8 | 900 ft |
| December | 17.8 | −637 ft | 26.3 | −33 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 KATY
DENSITY ALTITUDE
Field elevation 1,749 ft — the air behaves like 3,628 ft.
- PRESSURE ALT
- 1,750 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
- 8D7 — Clark County
Clark · elev 1,793 ft
- 1D7 — The Sigurd Anderson
Webster · elev 1,858 ft
- 3A9 — Arlington Municipal
Arlington · elev 1,818 ft
- 1D1 — Milbank Municipal
Milbank · elev 1,118 ft
- 6E5 — Wilder
Desmet · elev 1,730 ft
- KBKX — Brookings Regional
Brookings · elev 1,648 ft
- 8D3 — Sisseton Municipal
Sisseton · elev 1,162 ft
- KMDS — Madison Municipal
Madison · elev 1,718 ft
Frequently asked questions
How high does density altitude get at KATY in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Watertown Regional reaches roughly 3,628 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 KATY on an average day?
It swings with the seasons: from roughly −1,043 ft at the coldest month's average temperature to about 2,943 ft at the warmest month's — all from a constant field elevation of 1,749 ft. The month-by-month table above carries the full year.
What is the field elevation of Watertown Regional?
1,749 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KATY (ICAO) / ATY (FAA), in Watertown, South Dakota.