Mount Ayr, Iowa · field elev 1,265 ft
Density Altitude at Judge Lewis Field/Mount Ayr Municipal (1Y3)
Judge Lewis Field/Mount Ayr Municipal sits at 1,265 ft, and even a typical July afternoon (85 °F) only lifts density altitude to about 3,198 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 | 21.8 | −958 ft | 31.9 | −246 ft |
| February | 26.5 | −624 ft | 36.8 | 93 ft |
| March | 38.5 | 210 ft | 49.4 | 946 ft |
| April | 49.7 | 966 ft | 61.4 | 1,735 ft |
| May | 60.2 | 1,657 ft | 70.8 | 2,337 ft |
| June | 70.0 | 2,286 ft | 80.3 | 2,932 ft |
| July | 74.2 | 2,552 ft | 84.6 | 3,198 ft |
| August | 72.5 | 2,445 ft | 83.3 | 3,118 ft |
| September | 64.5 | 1,935 ft | 76.4 | 2,690 ft |
| October | 52.1 | 1,126 ft | 64.1 | 1,909 ft |
| November | 38.4 | 203 ft | 49.0 | 920 ft |
| December | 27.2 | −575 ft | 36.8 | 93 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 1Y3
DENSITY ALTITUDE
Field elevation 1,265 ft — the air behaves like 3,222 ft.
- PRESSURE ALT
- 1,266 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
- KLWD — Lamoni Municipal
Lamoni · elev 1,131 ft
- KCSQ — Creston Municipal
Creston · elev 1,300 ft
- Y46 — Bedford Municipal
Bedford · elev 1,201 ft
- KCRZ — Corning Municipal
Corning · elev 1,274 ft
- I75 — Osceola Municipal
Osceola · elev 1,115 ft
- KICL — Schenck Field
Clarinda · elev 996 ft
- KGFZ — Greenfield Municipal
Greenfield · elev 1,364 ft
- 3Y3 — Winterset Municipal
Winterset · elev 1,116 ft
Frequently asked questions
How high does density altitude get at 1Y3 in summer?
On a typical July afternoon — around 85 °F at the nearest NOAA normals station — density altitude at Judge Lewis Field/Mount Ayr Municipal reaches roughly 3,198 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 1Y3 on an average day?
It swings with the seasons: from roughly −958 ft at the coldest month's average temperature to about 2,552 ft at the warmest month's — all from a constant field elevation of 1,265 ft. The month-by-month table above carries the full year.
What is the field elevation of Judge Lewis Field/Mount Ayr Municipal?
1,265 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 1Y3 (FAA), in Mount Ayr, Iowa.