Sibley, Iowa · field elev 1,538 ft
Density Altitude at Sibley Municipal (KISB)
Sibley Municipal sits at 1,538 ft, and even a typical July afternoon (82 °F) only lifts density altitude to about 3,377 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 | 13.9 | −1,184 ft | 23.1 | −523 ft |
| February | 18.4 | −859 ft | 28.0 | −177 ft |
| March | 30.8 | 18 ft | 41.0 | 720 ft |
| April | 44.3 | 943 ft | 56.1 | 1,726 ft |
| May | 57.2 | 1,798 ft | 68.8 | 2,545 ft |
| June | 67.8 | 2,481 ft | 78.9 | 3,179 ft |
| July | 71.2 | 2,697 ft | 82.1 | 3,377 ft |
| August | 68.9 | 2,551 ft | 79.9 | 3,241 ft |
| September | 61.4 | 2,071 ft | 73.8 | 2,861 ft |
| October | 47.7 | 1,171 ft | 59.8 | 1,967 ft |
| November | 32.4 | 129 ft | 42.6 | 828 ft |
| December | 19.5 | −780 ft | 28.3 | −156 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 KISB
DENSITY ALTITUDE
Field elevation 1,538 ft — the air behaves like 3,371 ft.
- PRESSURE ALT
- 1,539 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 Iowa fields
- KSHL — Sheldon Regional
Sheldon · elev 1,419 ft
- KRRQ — Rock Rapids Municipal
Rock Rapids · elev 1,363 ft
- 1Y9 — Paullina Municipal
Paullina · elev 1,385 ft
- 4D8 — Fuller
Milford · elev 1,439 ft
- 0F3 — Spirit Lake Municipal
Spirit Lake · elev 1,434 ft
- KSPW — Spencer Municipal
Spencer · elev 1,339 ft
- 2VA — Zangger Vintage Airpark
Larchwood · elev 1,478 ft
- KSXK — Sioux County Regional
Maurice · elev 1,409 ft
Frequently asked questions
How high does density altitude get at KISB in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Sibley Municipal reaches roughly 3,377 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 KISB on an average day?
It swings with the seasons: from roughly −1,184 ft at the coldest month's average temperature to about 2,697 ft at the warmest month's — all from a constant field elevation of 1,538 ft. The month-by-month table above carries the full year.
What is the field elevation of Sibley Municipal?
1,538 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KISB (ICAO) / ISB (FAA), in Sibley, Iowa.