Prairie Du Sac, Wisconsin · field elev 832 ft
Density Altitude at Sauk/Prairie (91C)
Sauk/Prairie sits at 832 ft, and even a typical July afternoon (82 °F) only lifts density altitude to about 2,509 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 | 17.2 | −1,833 ft | 26.5 | −1,166 ft |
| February | 20.9 | −1,566 ft | 31.0 | −849 ft |
| March | 33.2 | −696 ft | 43.7 | 26 ft |
| April | 45.2 | 128 ft | 56.8 | 901 ft |
| May | 57.3 | 934 ft | 69.2 | 1,704 ft |
| June | 67.3 | 1,582 ft | 78.5 | 2,291 ft |
| July | 70.7 | 1,800 ft | 82.0 | 2,509 ft |
| August | 69.0 | 1,691 ft | 80.2 | 2,397 ft |
| September | 61.2 | 1,189 ft | 73.5 | 1,977 ft |
| October | 49.1 | 390 ft | 60.5 | 1,143 ft |
| November | 35.5 | −536 ft | 45.2 | 128 ft |
| December | 23.8 | −1,358 ft | 32.5 | −745 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 91C
DENSITY ALTITUDE
Field elevation 832 ft — the air behaves like 2,509 ft.
- PRESSURE ALT
- 833 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 Wisconsin fields
- KDLL — Baraboo/Wisconsin Dells Regional
Baraboo · elev 980 ft
- C29 — Middleton Municipal/Morey Field
Middleton · elev 928 ft
- 6P3 — Waunakee
Waunakee · elev 954 ft
- C35 — Reedsburg Municipal
Reedsburg · elev 906 ft
- KLNR — Tri-County Regional
Lone Rock · elev 717 ft
- C47 — Portage Municipal
Portage · elev 825 ft
- KMSN — Dane County Regional/Truax Field
Madison · elev 887 ft
- 93C — Richland
Richland Center · elev 742 ft
Frequently asked questions
How high does density altitude get at 91C in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Sauk/Prairie reaches roughly 2,509 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 91C on an average day?
It swings with the seasons: from roughly −1,833 ft at the coldest month's average temperature to about 1,800 ft at the warmest month's — all from a constant field elevation of 832 ft. The month-by-month table above carries the full year.
What is the field elevation of Sauk/Prairie?
832 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 91C (FAA), in Prairie Du Sac, Wisconsin.