Loris, South Carolina · field elev 99 ft
Density Altitude at Twin City (5J9)
Twin City sits at 99 ft, and even a typical July afternoon (88 °F) only lifts density altitude to about 1,998 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 | 45.1 | −790 ft | 55.8 | −71 ft |
| February | 47.4 | −634 ft | 58.5 | 108 ft |
| March | 53.5 | −224 ft | 65.1 | 539 ft |
| April | 61.4 | 298 ft | 73.0 | 1,047 ft |
| May | 69.4 | 816 ft | 79.6 | 1,464 ft |
| June | 76.6 | 1,275 ft | 85.2 | 1,813 ft |
| July | 80.1 | 1,495 ft | 88.2 | 1,998 ft |
| August | 78.7 | 1,407 ft | 86.8 | 1,911 ft |
| September | 73.8 | 1,097 ft | 82.4 | 1,639 ft |
| October | 63.8 | 454 ft | 74.4 | 1,136 ft |
| November | 54.0 | −191 ft | 65.5 | 565 ft |
| December | 47.8 | −606 ft | 58.6 | 114 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 5J9
DENSITY ALTITUDE
Field elevation 99 ft — the air behaves like 1,985 ft.
- PRESSURE ALT
- 100 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 South Carolina fields
- KCRE — Grand Strand
North Myrtle Beach · elev 32 ft
- KHYW — Conway-Horry County
Conway · elev 35 ft
- KMAO — Marion County
Marion · elev 93 ft
- KMYR — Myrtle Beach International
Myrtle Beach · elev 25 ft
- KDLC — Dillon County
Dillon · elev 133 ft
- KFLO — Florence Regional
Florence · elev 147 ft
- 9W9 — Clio Crop Care
Clio · elev 192 ft
- 51J — Lake City Municipal Cj Evans Field
Lake City · elev 80 ft
Frequently asked questions
How high does density altitude get at 5J9 in summer?
On a typical July afternoon — around 88 °F at the nearest NOAA normals station — density altitude at Twin City reaches roughly 1,998 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 5J9 on an average day?
It swings with the seasons: from roughly −790 ft at the coldest month's average temperature to about 1,495 ft at the warmest month's — all from a constant field elevation of 99 ft. The month-by-month table above carries the full year.
What is the field elevation of Twin City?
99 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 5J9 (FAA), in Loris, South Carolina.