Jacksonville, Florida · field elev 30 ft
Density Altitude at Jacksonville International (KJAX)
Jacksonville International sits at 30 ft, and even a typical July afternoon (92 °F) only lifts density altitude to about 2,140 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 | 54.2 | −263 ft | 65.5 | 480 ft |
| February | 57.5 | −44 ft | 68.9 | 699 ft |
| March | 62.4 | 278 ft | 74.3 | 1,045 ft |
| April | 68.1 | 648 ft | 79.8 | 1,392 ft |
| May | 74.9 | 1,083 ft | 85.9 | 1,772 ft |
| June | 80.3 | 1,423 ft | 89.9 | 2,018 ft |
| July | 82.5 | 1,561 ft | 91.9 | 2,140 ft |
| August | 82.1 | 1,536 ft | 90.8 | 2,073 ft |
| September | 78.8 | 1,329 ft | 87.2 | 1,852 ft |
| October | 71.2 | 847 ft | 80.9 | 1,461 ft |
| November | 62.3 | 272 ft | 73.2 | 975 ft |
| December | 56.7 | −97 ft | 67.5 | 609 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 KJAX
DENSITY ALTITUDE
Field elevation 30 ft — the air behaves like 2,146 ft.
- PRESSURE ALT
- 31 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
- KCRG — Jacksonville Exec At Craig
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- KFHB — Fernandina Beach Municipal
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- KHEG — Herlong Recreational
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- 01J — Hilliard Airpark
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- KVQQ — Cecil
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- KSGJ — St Augustine
St Augustine · elev 10 ft
- 42J — Keystone Heights
Keystone Heights · elev 196 ft
- KLCQ — Lake City Gateway
Lake City · elev 201 ft
Frequently asked questions
How high does density altitude get at KJAX in summer?
On a typical July afternoon — around 92 °F at the nearest NOAA normals station — density altitude at Jacksonville International reaches roughly 2,140 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 KJAX on an average day?
It swings with the seasons: from roughly −263 ft at the coldest month's average temperature to about 1,561 ft at the warmest month's — all from a constant field elevation of 30 ft. The month-by-month table above carries the full year.
What is the field elevation of Jacksonville International?
30 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KJAX (ICAO) / JAX (FAA), in Jacksonville, Florida.