Sterling/Rockfalls, Illinois · field elev 648 ft
Density Altitude at Whiteside County/Jos H Bittorf Field (KSQI)
Whiteside County/Jos H Bittorf Field sits at 648 ft, and even a typical July afternoon (83 °F) only lifts density altitude to about 2,328 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 | 21.3 | −1,768 ft | 29.0 | −1,220 ft |
| February | 25.5 | −1,468 ft | 33.6 | −898 ft |
| March | 37.3 | −641 ft | 46.3 | −26 ft |
| April | 49.4 | 182 ft | 59.9 | 877 ft |
| May | 60.9 | 942 ft | 71.0 | 1,593 ft |
| June | 70.2 | 1,542 ft | 79.8 | 2,148 ft |
| July | 73.5 | 1,752 ft | 82.7 | 2,328 ft |
| August | 71.9 | 1,650 ft | 81.4 | 2,247 ft |
| September | 64.6 | 1,182 ft | 75.3 | 1,865 ft |
| October | 52.4 | 382 ft | 62.8 | 1,066 ft |
| November | 39.0 | −524 ft | 47.6 | 61 ft |
| December | 27.3 | −1,340 ft | 34.5 | −835 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 KSQI
DENSITY ALTITUDE
Field elevation 648 ft — the air behaves like 2,346 ft.
- PRESSURE ALT
- 649 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 Illinois fields
- C73 — Dixon Municipal-Charles R Walgreen Field
Dixon · elev 785 ft
- C55 — Ogle County
Mount Morris · elev 929 ft
- C82 — Bresson
Compton · elev 769 ft
- KSFY — Tri-Township
Savanna · elev 616 ft
- 3G8 — Gen-Airpark
Geneseo · elev 645 ft
- KRPJ — Rochelle Municipal/Koritz Field
Rochelle · elev 781 ft
- KFEP — Albertus
Freeport · elev 859 ft
- KVYS — Illinois Valley Regional-Walter A Duncan Field
Peru · elev 654 ft
Frequently asked questions
How high does density altitude get at KSQI in summer?
On a typical July afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Whiteside County/Jos H Bittorf Field reaches roughly 2,328 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 KSQI on an average day?
It swings with the seasons: from roughly −1,768 ft at the coldest month's average temperature to about 1,752 ft at the warmest month's — all from a constant field elevation of 648 ft. The month-by-month table above carries the full year.
What is the field elevation of Whiteside County/Jos H Bittorf Field?
648 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KSQI (ICAO) / SQI (FAA), in Sterling/Rockfalls, Illinois.