Wisconsin Rapids, Wisconsin · field elev 1,021 ft
Density Altitude at Alexander Field South Wood County (KISW)
Alexander Field South Wood County sits at 1,021 ft, and even a typical July afternoon (82 °F) only lifts density altitude to about 2,765 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 | 16.1 | −1,675 ft | 24.5 | −1,072 ft |
| February | 19.8 | −1,408 ft | 29.1 | −746 ft |
| March | 31.6 | −571 ft | 41.5 | 111 ft |
| April | 44.3 | 301 ft | 55.7 | 1,062 ft |
| May | 56.6 | 1,121 ft | 68.5 | 1,891 ft |
| June | 66.4 | 1,757 ft | 78.1 | 2,497 ft |
| July | 70.6 | 2,025 ft | 82.4 | 2,765 ft |
| August | 68.4 | 1,885 ft | 79.7 | 2,597 ft |
| September | 60.3 | 1,363 ft | 71.8 | 2,101 ft |
| October | 47.5 | 517 ft | 57.9 | 1,206 ft |
| November | 34.0 | −404 ft | 42.5 | 179 ft |
| December | 21.9 | −1,257 ft | 29.5 | −718 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 KISW
DENSITY ALTITUDE
Field elevation 1,021 ft — the air behaves like 2,740 ft.
- PRESSURE ALT
- 1,022 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
- KSTE — Stevens Point Municipal
Stevens Point · elev 1,110 ft
- KDAF — Necedah
Necedah · elev 919 ft
- KMFI — Marshfield Municipal
Marshfield · elev 1,278 ft
- 63C — Adams County Legion Field
Friendship (Adams) · elev 979 ft
- KCWA — Central Wisconsin
Mosinee · elev 1,277 ft
- W23 — Wild Rose Idlewild
Wild Rose · elev 908 ft
- Y50 — Wautoma Municipal
Wautoma · elev 859 ft
- KVIQ — Neillsville Municipal
Neillsville · elev 1,238 ft
Frequently asked questions
How high does density altitude get at KISW in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Alexander Field South Wood County reaches roughly 2,765 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 KISW on an average day?
It swings with the seasons: from roughly −1,675 ft at the coldest month's average temperature to about 2,025 ft at the warmest month's — all from a constant field elevation of 1,021 ft. The month-by-month table above carries the full year.
What is the field elevation of Alexander Field South Wood County?
1,021 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KISW (ICAO) / ISW (FAA), in Wisconsin Rapids, Wisconsin.