San Antonio, Texas · field elev 551 ft
Density Altitude at Horizon (74R)
Horizon sits at 551 ft, and even a typical August afternoon (98 °F) only lifts density altitude to about 3,112 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 | 53.5 | 335 ft | 64.7 | 1,069 ft |
| February | 58.0 | 633 ft | 69.2 | 1,359 ft |
| March | 64.4 | 1,050 ft | 75.3 | 1,747 ft |
| April | 71.1 | 1,480 ft | 81.9 | 2,160 ft |
| May | 78.2 | 1,929 ft | 88.1 | 2,542 ft |
| June | 83.8 | 2,278 ft | 93.6 | 2,877 ft |
| July | 85.8 | 2,401 ft | 96.2 | 3,034 ft |
| August | 86.6 | 2,450 ft | 97.5 | 3,112 ft |
| September | 81.3 | 2,122 ft | 91.3 | 2,738 ft |
| October | 72.7 | 1,582 ft | 83.7 | 2,271 ft |
| November | 62.2 | 907 ft | 73.3 | 1,620 ft |
| December | 55.1 | 442 ft | 66.3 | 1,173 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 74R
DENSITY ALTITUDE
Field elevation 551 ft — the air behaves like 3,142 ft.
- PRESSURE ALT
- 552 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 Texas fields
- KSSF — Stinson Municipal
San Antonio · elev 578 ft
- 53T — Cannon Field
Somerset · elev 610 ft
- KSKF — Kelly Field
San Antonio · elev 691 ft
- KSAT — San Antonio International
San Antonio · elev 809 ft
- T94 — Twin-Oaks
San Antonio · elev 873 ft
- KCVB — Castroville Municipal
Castroville · elev 774 ft
- KPEZ — Pleasanton Municipal
Pleasanton · elev 430 ft
- 8T8 — San Geronimo Airpark
San Antonio · elev 1,040 ft
Frequently asked questions
How high does density altitude get at 74R in summer?
On a typical August afternoon — around 98 °F at the nearest NOAA normals station — density altitude at Horizon reaches roughly 3,112 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 74R on an average day?
It swings with the seasons: from roughly 335 ft at the coldest month's average temperature to about 2,450 ft at the warmest month's — all from a constant field elevation of 551 ft. The month-by-month table above carries the full year.
What is the field elevation of Horizon?
551 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 74R (FAA), in San Antonio, Texas.