Port St Joe, Florida · field elev 13 ft
Density Altitude at Costin (A51)
Costin sits at 13 ft, and even a typical July afternoon (90 °F) only lifts density altitude to about 1,985 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 | 54.0 | −297 ft | 63.7 | 342 ft |
| February | 56.8 | −111 ft | 66.3 | 511 ft |
| March | 61.7 | 211 ft | 70.9 | 807 ft |
| April | 67.3 | 575 ft | 76.3 | 1,151 ft |
| May | 74.8 | 1,055 ft | 83.7 | 1,614 ft |
| June | 80.7 | 1,427 ft | 88.5 | 1,911 ft |
| July | 82.2 | 1,521 ft | 89.7 | 1,985 ft |
| August | 82.2 | 1,521 ft | 89.4 | 1,967 ft |
| September | 79.2 | 1,333 ft | 86.7 | 1,800 ft |
| October | 71.5 | 845 ft | 80.7 | 1,427 ft |
| November | 62.1 | 238 ft | 72.5 | 909 ft |
| December | 56.5 | −131 ft | 66.0 | 491 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 A51
DENSITY ALTITUDE
Field elevation 13 ft — the air behaves like 2,003 ft.
- PRESSURE ALT
- 14 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 Florida fields
- KAAF — Apalachicola Regional-Cleve Randolph Field
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Apalachicola · elev 3 ft
- X13 — Carrabelle-Thompson
Carrabelle · elev 20 ft
- KECP — Northwest Florida Beaches International
Panama City · elev 69 ft
- F95 — Calhoun County
Blountstown · elev 121 ft
- 2J0 — Wakulla County
Panacea · elev 11 ft
- KTLH — Tallahassee International
Tallahassee · elev 83 ft
- 2J9 — Quincy Municipal
Quincy · elev 221 ft
Frequently asked questions
How high does density altitude get at A51 in summer?
On a typical July afternoon — around 90 °F at the nearest NOAA normals station — density altitude at Costin reaches roughly 1,985 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 A51 on an average day?
It swings with the seasons: from roughly −297 ft at the coldest month's average temperature to about 1,521 ft at the warmest month's — all from a constant field elevation of 13 ft. The month-by-month table above carries the full year.
What is the field elevation of Costin?
13 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is A51 (FAA), in Port St Joe, Florida.