Jakolof Bay, Alaska · field elev 5 ft
Density Altitude at Jakolof Bay (4Z9)
Jakolof Bay sits at 5 ft, and even a typical July afternoon (62 °F) only lifts density altitude to about 208 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 | 25.8 | −2,253 ft | 30.8 | −1,898 ft |
| February | 28.4 | −2,067 ft | 33.5 | −1,708 ft |
| March | 29.5 | −1,990 ft | 35.5 | −1,568 ft |
| April | 36.9 | −1,471 ft | 43.3 | −1,029 ft |
| May | 44.3 | −961 ft | 51.2 | −494 ft |
| June | 50.9 | −514 ft | 58.1 | −35 ft |
| July | 55.4 | −214 ft | 61.8 | 208 ft |
| August | 54.7 | −260 ft | 61.5 | 189 ft |
| September | 48.6 | −669 ft | 54.7 | −260 ft |
| October | 39.7 | −1,277 ft | 45.4 | −886 ft |
| November | 31.5 | −1,848 ft | 36.1 | −1,526 ft |
| December | 28.2 | −2,082 ft | 32.9 | −1,750 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 4Z9
DENSITY ALTITUDE
Field elevation 5 ft — the air behaves like 221 ft.
- PRESSURE ALT
- 6 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 Alaska fields
- PASO — Seldovia
Seldovia · elev 29 ft
- PGM — Port Graham
Port Graham · elev 93 ft
- PAHO — Homer
Homer · elev 84 ft
- PAAW — Nanwalek
Nanwalek · elev 27 ft
- NIN — Ninilchik
Ninilchik · elev 276 ft
- 5KS — Kasilof
Kasilof · elev 125 ft
- PASX — Soldotna
Soldotna · elev 113 ft
- PAEN — Kenai Municipal
Kenai · elev 100 ft
Frequently asked questions
How high does density altitude get at 4Z9 in summer?
On a typical July afternoon — around 62 °F at the nearest NOAA normals station — density altitude at Jakolof Bay reaches roughly 208 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 4Z9 on an average day?
It swings with the seasons: from roughly −2,253 ft at the coldest month's average temperature to about −214 ft at the warmest month's — all from a constant field elevation of 5 ft. The month-by-month table above carries the full year.
What is the field elevation of Jakolof Bay?
5 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4Z9 (FAA), in Jakolof Bay, Alaska.