City report · United States
Honolulu
Measured across a 2 km radius around Downtown, Honolulu, HI, USA (12.57 km²)
- Tree cover
- 24.8%
- Air quality
- 52Moderate
- Trees in this area
- 66.5K
- More trees needed
- 13.9K
- Area analysed
- 10.72 km²land, in a 12.57 km² circle
- Satellite image
- Sep 14, 2026
Honolulu's tree count comes to 66,459 trees across 10.72 km² of land — 5 points below the 30% tree-cover level considered healthy for this area, meaning roughly 13,935 more trees would close the gap. Air quality currently reads AQI 52 (Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Tree cover detail
Below target
24.8% tree cover against a 30% healthy-neighbourhood target, across 10.72 km² of land.
Trees in this area
66,459
Target trees
80,394
More trees needed
13,935
CO₂ if planted / yr
306.6 t
Air quality detail
AQI 52Moderate
Observed Sep 21, 17:00 local time via Open-Meteo / CAMS. Values in µg/m³.
Health signal
Unusually sensitive people should consider limiting long outdoor exertion.
PM2.5
9.7
PM10
16.4
NO₂
1.4
O₃
42.0
SO₂
0.9
CO
106.0
Frequently asked
Questions about Honolulu
What is the tree count in Honolulu?
Honolulu has an estimated 66,459 trees across the 10.72 km² of land measured — 24.8% tree cover, 5 percentage points short of the 30% tree-cover target set for this area.
How many more trees does Honolulu need?
Honolulu needs roughly 13,935 more trees to close a 5-point shortfall against its 30% tree-cover target — about 306.6 t of extra CO₂ absorbed per year once grown.
What is the air quality (AQI) in Honolulu right now?
The latest reading for Honolulu shows an AQI of 52 (Moderate), observed Sep 21, 17:00 local time via Open-Meteo / CAMS. Unusually sensitive people should consider limiting long outdoor exertion.
How is Honolulu's tree cover and air quality measured?
Tree cover is measured from Sentinel-2 L2A (ESA Copernicus) via Earth Search satellite imagery at 10 m detail across a 2 km radius around Downtown; the tree count is an estimate derived from that cover. Air-quality readings come from Open-Meteo / CAMS and may differ from street-level monitors.
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