New York, New York · field elev 99 ft
Density Altitude at Long Island Mac Arthur (KISP)
Long Island Mac Arthur sits at 99 ft, and even a typical July afternoon (83 °F) only lifts density altitude to about 1,664 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 | 31.9 | −1,703 ft | 39.2 | −1,194 ft |
| February | 33.3 | −1,604 ft | 41.0 | −1,070 ft |
| March | 39.9 | −1,146 ft | 47.7 | −613 ft |
| April | 49.7 | −478 ft | 58.3 | 94 ft |
| May | 59.5 | 173 ft | 68.3 | 746 ft |
| June | 69.0 | 791 ft | 77.2 | 1,313 ft |
| July | 75.0 | 1,174 ft | 82.8 | 1,664 ft |
| August | 73.7 | 1,091 ft | 81.4 | 1,576 ft |
| September | 66.9 | 655 ft | 74.8 | 1,161 ft |
| October | 55.7 | −78 ft | 64.1 | 474 ft |
| November | 45.6 | −756 ft | 53.6 | −217 ft |
| December | 37.1 | −1,339 ft | 44.4 | −837 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 KISP
DENSITY ALTITUDE
Field elevation 99 ft — the air behaves like 1,676 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 New York fields
- 23N — Bayport Aerodrome
Bayport · elev 39 ft
- KHWV — Brookhaven
Shirley · elev 81 ft
- KFRG — Republic
Farmingdale · elev 82 ft
- KFOK — Francis S Gabreski
Westhampton Beach · elev 66 ft
- 21N — Mattituck
Mattituck · elev 30 ft
- KHPN — Westchester County
White Plains · elev 439 ft
- KJFK — John F Kennedy International
New York · elev 13 ft
- KLGA — Laguardia
New York · elev 21 ft
Frequently asked questions
How high does density altitude get at KISP in summer?
On a typical July afternoon — around 83 °F at the nearest NOAA normals station — density altitude at Long Island Mac Arthur reaches roughly 1,664 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 KISP on an average day?
It swings with the seasons: from roughly −1,703 ft at the coldest month's average temperature to about 1,174 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 Long Island Mac Arthur?
99 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KISP (ICAO) / ISP (FAA), in New York, New York.