Janesville, Wisconsin · field elev 808 ft
Density Altitude at Southern Wisconsin Regional (KJVL)
Southern Wisconsin Regional sits at 808 ft, and even a typical July afternoon (83 °F) only lifts density altitude to about 2,566 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 | 19.9 | −1,668 ft | 28.3 | −1,069 ft |
| February | 23.5 | −1,410 ft | 32.4 | −782 ft |
| March | 35.0 | −601 ft | 44.6 | 57 ft |
| April | 47.0 | 219 ft | 57.9 | 943 ft |
| May | 58.9 | 1,009 ft | 69.9 | 1,719 ft |
| June | 68.9 | 1,655 ft | 79.9 | 2,349 ft |
| July | 72.6 | 1,891 ft | 83.4 | 2,566 ft |
| August | 70.6 | 1,764 ft | 81.7 | 2,461 ft |
| September | 63.0 | 1,276 ft | 75.1 | 2,049 ft |
| October | 50.6 | 460 ft | 61.7 | 1,191 ft |
| November | 37.4 | −435 ft | 46.3 | 172 ft |
| December | 25.8 | −1,246 ft | 33.5 | −705 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 KJVL
DENSITY ALTITUDE
Field elevation 808 ft — the air behaves like 2,542 ft.
- PRESSURE ALT
- 809 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
- 44C — Beloit
Beloit · elev 817 ft
- C37 — Brodhead
Brodhead · elev 792 ft
- 58C — Jana
Edgerton · elev 843 ft
- 54W — Albany
Albany · elev 820 ft
- 7V3 — Big Foot Airfield
Walworth · elev 948 ft
- 5Y3 — Gutzmer'S Twin Oaks
Whitewater · elev 821 ft
- C59 — Lake Lawn
Delavan · elev 981 ft
- 61C — Fort Atkinson Municipal
Fort Atkinson · elev 800 ft
Frequently asked questions
How high does density altitude get at KJVL in summer?
On a typical July afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Southern Wisconsin Regional reaches roughly 2,566 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 KJVL on an average day?
It swings with the seasons: from roughly −1,668 ft at the coldest month's average temperature to about 1,891 ft at the warmest month's — all from a constant field elevation of 808 ft. The month-by-month table above carries the full year.
What is the field elevation of Southern Wisconsin Regional?
808 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KJVL (ICAO) / JVL (FAA), in Janesville, Wisconsin.