City report · United States
San Mateo
Measured across a 2 km radius around Downtown, San Mateo, CA, USA (12.57 km²)
- Tree cover
- 27.7%
- Air quality
- 51Moderate
- Trees in this area
- 87.0K
- More trees needed
- 7.2K
- Area analysed
- 12.57 km²
- Satellite image
- Sep 12, 2026
San Mateo's tree count comes to 87,022 trees across 12.57 km² — 2 points below the 30% tree-cover level considered healthy for this area, meaning roughly 7,226 more trees would close the gap. Air quality currently reads AQI 51 (Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Tree cover detail
Below target
27.7% tree cover against a 30% healthy-neighbourhood target, across 12.57 km².
Trees in this area
87,022
Target trees
94,248
More trees needed
7,226
CO₂ if planted / yr
159.0 t
Air quality detail
AQI 51Moderate
Observed Sep 21, 20:00 local time via Open-Meteo / CAMS. Values in µg/m³.
Health signal
Unusually sensitive people should consider limiting long outdoor exertion.
PM2.5
9.6
PM10
15.4
NO₂
5.4
O₃
64.0
SO₂
0.8
CO
119.0
Frequently asked
Questions about San Mateo
What is the tree count in San Mateo?
San Mateo has an estimated 87,022 trees across the 12.57 km² measured — 27.7% tree cover, 2 percentage points short of the 30% tree-cover target set for this area.
How many more trees does San Mateo need?
San Mateo needs roughly 7,226 more trees to close a 2-point shortfall against its 30% tree-cover target — about 159.0 t of extra CO₂ absorbed per year once grown.
What is the air quality (AQI) in San Mateo right now?
The latest reading for San Mateo shows an AQI of 51 (Moderate), observed Sep 21, 20:00 local time via Open-Meteo / CAMS. Unusually sensitive people should consider limiting long outdoor exertion.
How is San Mateo'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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