Half Moon Bay, California · field elev 66 ft
Density Altitude at Half Moon Bay (KHAF)
Half Moon Bay sits at 66 ft, and even a typical September afternoon (66 °F) only lifts density altitude to about 582 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 | 51.4 | −405 ft | 59.4 | 126 ft |
| February | 51.3 | −412 ft | 59.5 | 133 ft |
| March | 52.1 | −358 ft | 60.4 | 192 ft |
| April | 52.9 | −305 ft | 61.0 | 231 ft |
| May | 54.9 | −171 ft | 61.7 | 277 ft |
| June | 56.9 | −39 ft | 63.9 | 420 ft |
| July | 58.8 | 87 ft | 64.8 | 479 ft |
| August | 59.7 | 146 ft | 65.6 | 531 ft |
| September | 58.8 | 87 ft | 66.4 | 582 ft |
| October | 57.1 | −26 ft | 66.4 | 582 ft |
| November | 53.7 | −251 ft | 62.6 | 336 ft |
| December | 50.9 | −439 ft | 59.0 | 100 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 KHAF
DENSITY ALTITUDE
Field elevation 66 ft — the air behaves like 557 ft.
- PRESSURE ALT
- 67 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 California fields
- KSFO — San Francisco International
San Francisco · elev 13 ft
- KSQL — San Carlos
San Carlos · elev 6 ft
- KOAK — Oakland San Francisco Bay
Oakland · elev 9 ft
- KPAO — Palo Alto
Palo Alto · elev 7 ft
- KHWD — Hayward Exec
Hayward · elev 52 ft
- KSJC — Norman Y Mineta San Jose International
San Jose · elev 62 ft
- KLVK — Livermore Municipal
Livermore · elev 400 ft
- KRHV — Reid-Hillview Of Santa Clara County
San Jose · elev 135 ft
Frequently asked questions
How high does density altitude get at KHAF in summer?
On a typical September afternoon — around 66 °F at the nearest NOAA normals station — density altitude at Half Moon Bay reaches roughly 582 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 KHAF on an average day?
It swings with the seasons: from roughly −439 ft at the coldest month's average temperature to about 146 ft at the warmest month's — all from a constant field elevation of 66 ft. The month-by-month table above carries the full year.
What is the field elevation of Half Moon Bay?
66 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KHAF (ICAO) / HAF (FAA), in Half Moon Bay, California.