City report · Saint Helena
Jamestown Air quality today
Air quality in Jamestown currently reads AQI 70 (Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
AQI 70
Air quality right now
Moderate
- PM2.5, fine particles (µg/m³)
- 21.5
- tree cover
- 1.0%
- trees in this area
- 716
- more trees needed
- 20.8K
Measured across a 2 km radius around Jamestown STHL 1ZZ, St Helena, Ascension and Tristan da Cunha (12.57 km²), from a satellite image of Jul 9, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Jamestown · AQI 70 (Moderate)
Jamestown's tree count comes to 716 trees across 2.87 km² of land, 29 points below the 30% tree-cover level considered healthy for this area, so roughly 20,772 more trees would close the gap.
Air quality detail
Air quality in Jamestown today: AQI 70, Moderate
Main pollutant: PM2.5 · Observed Nov 10, 20:00 local time via Open-Meteo / CAMS, US EPA index. Values in µg/m³.
Model estimate · no ground station nearby
Health signal
Unusually sensitive people should consider limiting long outdoor exertion.
PM2.5
21.5
PM10
36.7
NO₂
0.0
O₃
62.0
SO₂
0.2
CO
71.0
- Outdoor exercise
- Fine for most people; unusually sensitive people should take long or hard exercise easier
- Windows
- Fine to open; close them if you are sensitive to pollution
- Mask
- Not needed for most people
- Air purifier
- Worth running if you are sensitive
Over the last 7 days, the CAMS air-quality model put Jamestown's daily AQI at 62 on average, from 56 on Nov 4 to an hourly peak of 70 on Nov 5.
Where Jamestown stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Jamestown: Critically low
1.0% tree cover against a 30% healthy-neighborhood target, across 2.87 km² of land.
Trees in this area
716
Target trees
21,488
More trees needed
20,772
CO₂ if planted / yr
457.0 t
Deforestation · 2001–2025
How much forest has Jamestown lost?
There was almost no forest around Jamestown in 2000, so there has been almost nothing to lose since. Only fairly dense woodland counts as forest in these maps, so scattered street and garden trees don't show up here.
The forest-loss maps don't cover this area.
2017: satellite photo from May 2017 of a 5 × 5 km area in the city center.
These figures cover everything within 10 km of the city center, a wider area than the report above, because forest is usually lost at a city's edges.
Source: Hansen/UMD/Google/USGS/NASA, Global Forest Change (GFC-2025-v1.13); causes: WRI/Google DeepMind drivers of forest loss; both CC BY 4.0, summed by Airleaf for each area. Images: contains modified Copernicus Sentinel data. How it's measured
In the same region
Measured cities near Jamestown
Same 2 km radius, same index — so they compare directly.
- Mossamedes1915.4 km
Angola
- Tree cover
- 1%
- Air quality
- 61
- Lubango2061.6 km
Angola
- Tree cover
- 7%
- Air quality
- 24
- Baía Farta2070.7 km
Angola
- Tree cover
- 0%
- Air quality
- 55
- Benguela2093.2 km
Angola
- Tree cover
- 7%
- Air quality
- 56
- Lobito2112.5 km
Angola
- Tree cover
- 3%
- Air quality
- 56
- Bocoio2173.5 km
Angola
- Tree cover
- 7%
- Air quality
- 49
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Frequently asked
Questions about Jamestown
What is the air quality (AQI) in Jamestown right now?
The latest reading for Jamestown shows an AQI of 70 (Moderate), observed Nov 10, 20:00 local time via Open-Meteo / CAMS, US EPA index. The main pollutant is PM2.5. Unusually sensitive people should consider limiting long outdoor exertion.
Is it safe to exercise outside in Jamestown today?
At AQI 70 (Moderate): fine for most people; unusually sensitive people should take long or hard exercise easier. Windows: fine to open; close them if you are sensitive to pollution. Masks: not needed for most people. The reading changes through the day, so check again before a long run or ride.
What has the air quality in Jamestown been like this week?
Over the last 7 days, the CAMS air-quality model put Jamestown's daily AQI at 62 on average, from 56 on Nov 4 to an hourly peak of 70 on Nov 5. No day averaged above 100, the level where the air turns unhealthy for sensitive groups.
How much forest has the area around Jamestown lost since 2001?
There was almost no forest around Jamestown in 2000, so there has been almost nothing to lose since. Only fairly dense woodland counts as forest in these maps, so scattered street and garden trees don't show up here.
What is the tree count in Jamestown?
Jamestown has an estimated 716 trees across the 2.87 km² of land measured — 1.0% tree cover, 29 percentage points short of the 30% tree-cover target set for this area.
How many more trees does Jamestown need?
Jamestown needs roughly 20,772 more trees to close a 29-point shortfall against its 30% tree-cover target — about 457.0 t of extra CO₂ absorbed per year once grown.
How are Jamestown's air quality and tree cover measured?
Air quality comes from ground monitoring stations via OpenAQ where one reports nearby, and otherwise, as here, from the Open-Meteo / CAMS model, which may differ from street-level monitors. 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 Jamestown STHL 1ZZ; the tree count is an estimate derived from that cover.
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