City report · Massachusetts, United States
Worcester Air quality today
Air quality in Worcester currently reads AQI 21 (Good): Air quality is satisfactory for everyone.
Air quality right now
AQI 21
Good
- PM2.5, fine particles (µg/m³)
- 2.8
- tree cover
- 27.0%
- trees in this area
- 84.4K
- more trees needed
- 9.4K
Measured across a 1.2 mi (2 km) radius around Central Business District, Worcester, MA, USA (4.9 sq mi), from a satellite image of Sep 15, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Worcester · AQI 21 (Good)
Worcester's tree count comes to 84,399 trees across 4.8 sq mi (12.51 km²) of land, 3 points below the 30% tree-cover level considered healthy for this area, so roughly 9,378 more trees would close the gap.
Air quality detail
Air quality in Worcester today: AQI 21, Good
Main pollutant: Ozone · Observed Nov 11, 09:00 local time via OpenAQ ground stations, US EPA index. Values in µg/m³.
Ground station · Worcester - Summer S, 0.4 mi (600 m) away · median of 2 stations
Health signal
Air quality is satisfactory for everyone.
PM2.5
2.8
PM10
9.0
NO₂
—
O₃
47.1
SO₂
0.3
CO
343.7
Data: OpenAQ · AirNow
- Outdoor exercise
- A good day to be active outside
- Windows
- Open them to air the house
- Mask
- Not needed
- Air purifier
- Not needed
Over the last 7 days, the CAMS air-quality model put Worcester's daily AQI at 29 on average, from 19 on Nov 8 to an hourly peak of 64 on Nov 4.
Where Worcester stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Worcester: Below target
27.0% tree cover against a 30% healthy-neighborhood target, across 4.8 sq mi (12.51 km²) of land.
Trees in this area
84,399
Target trees
93,777
More trees needed
9,378
CO₂ if planted / yr
206.3 t
Deforestation · 2001–2025
How much forest has Worcester lost?
Since 2001, the area within 10 km of Worcester has lost about 2,980 acres (1,210 hectares) of forest (about 2,300 football fields): 6.2% of the forest it had in 2000. Most of it (80%) was deforestation, forest cleared for good, mainly for towns and roads.
2017: satellite photo from June 2017 of a 5 × 5 km area about 7 km northeast of the city center.
- Forest lost since 2001
- 2,980 acres (1,210 ha)about 2,300 football fields
- Share of its forest
- 6.2%of what there was in 2000
- Cleared for good
- 2,380 acres (965 ha)deforestation: turned into farms, mines or towns
Forest loss has stayed about the same: about 151 acres (61 hectares) a year in 2021–2025, against 139 acres (56 hectares) a year in 2016–2020. The worst year was 2017, when about 277 acres (112 hectares) of forest were lost.
Acres of forest lost each year
Show the figures as a table
| Year | Cleared for good | Can grow back | Total |
|---|---|---|---|
| 2001 | 79 acres (32 ha) | 8 acres (3 ha) | 87 acres (35 ha) |
| 2002 | 183 acres (74 ha) | 8 acres (3 ha) | 192 acres (78 ha) |
| 2003 | 100 acres (40 ha) | 6 acres (2 ha) | 106 acres (43 ha) |
| 2004 | 81 acres (33 ha) | 9 acres (4 ha) | 90 acres (36 ha) |
| 2005 | 122 acres (49 ha) | 7 acres (3 ha) | 129 acres (52 ha) |
| 2006 | 105 acres (42 ha) | 5 acres (2 ha) | 110 acres (45 ha) |
| 2007 | 57 acres (23 ha) | 4 acres (2 ha) | 61 acres (25 ha) |
| 2008 | 46 acres (18 ha) | 5 acres (2 ha) | 51 acres (21 ha) |
| 2009 | 44 acres (18 ha) | 38 acres (15 ha) | 82 acres (33 ha) |
| 2010 | 120 acres (49 ha) | 35 acres (14 ha) | 155 acres (63 ha) |
| 2011 | 40 acres (16 ha) | 13 acres (5 ha) | 52 acres (21 ha) |
| 2012 | 106 acres (43 ha) | 14 acres (6 ha) | 121 acres (49 ha) |
| 2013 | 18 acres (7 ha) | 135 acres (55 ha) | 153 acres (62 ha) |
| 2014 | 45 acres (18 ha) | 8 acres (3 ha) | 52 acres (21 ha) |
| 2015 | 89 acres (36 ha) | 5 acres (2 ha) | 94 acres (38 ha) |
| 2016 | 99 acres (40 ha) | 10 acres (4 ha) | 108 acres (44 ha) |
| 2017 | 259 acres (105 ha) | 17 acres (7 ha) | 277 acres (112 ha) |
| 2018 | 67 acres (27 ha) | 9 acres (4 ha) | 76 acres (31 ha) |
| 2019 | 58 acres (23 ha) | 46 acres (19 ha) | 104 acres (42 ha) |
| 2020 | 79 acres (32 ha) | 49 acres (20 ha) | 128 acres (52 ha) |
| 2021 | 116 acres (47 ha) | 81 acres (33 ha) | 197 acres (80 ha) |
| 2022 | 190 acres (77 ha) | 7 acres (3 ha) | 196 acres (79 ha) |
| 2023 | 72 acres (29 ha) | 8 acres (3 ha) | 81 acres (33 ha) |
| 2024 | 83 acres (34 ha) | 57 acres (23 ha) | 140 acres (57 ha) |
| 2025 | 129 acres (52 ha) | 10 acres (4 ha) | 140 acres (57 ha) |
What is causing deforestation around Worcester?
- Towns and roadscleared for good79% · 2,340 acres (948 ha)
- Loggingcan grow back19% · 558 acres (226 ha)
- Mining and energycleared for good1.1% · 33 acres (13 ha)
Also: farms, pasture and plantations, unknown causes.
Causes for 2025 are estimates, based on what caused forest loss in the same places up to 2024.
Forest gained and lost, 2000–2020
- Forest in 2000
- 52,700 acres (21,300 ha)
- Forest in 2020
- 52,300 acres (21,200 ha)
- Overall change
- −408 acres (165 ha)less forest than in 2000
Comparing satellite maps from 2000 and 2020, the forest around Worcester stayed about the same size, at about 52,300 acres (21,200 hectares): new forest grew on about 1,280 acres (519 hectares), and about 1,690 acres (684 hectares) were lost.
These 2000 and 2020 maps, from the University of Maryland, count any land with trees taller than 5 m as forest, including plantations and orchards. Forest that was cut or burned and had grown back by 2020 counts in both years, so the loss here is smaller than the yearly figures.
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. Forest gained and lost 2000–2020: Potapov et al. 2022, UMD GLAD Global Land Cover and Land Use Change, CC BY 4.0. Images: contains modified Copernicus Sentinel data. How it's measured
In the same region
Measured cities near Worcester
Same 2 km radius, same index — so they compare directly.
- Lowell57.4 km
United States
- Tree cover
- 31%
- Air quality
- 19
- Providence58.4 km
United States
- Tree cover
- 25%
- Air quality
- 31
- Boston62.0 km
United States
- Tree cover
- 12%
- Air quality
- 18
- Springfield67.3 km
United States
- Tree cover
- 31%
- Air quality
- 12
- Manchester86.3 km
United States
- Tree cover
- 34%
- Air quality
- 20
- Hartford91.6 km
United States
- Tree cover
- 30%
- Air quality
- 19
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Frequently asked
Questions about Worcester
What is the air quality (AQI) in Worcester right now?
The latest reading for Worcester shows an AQI of 21 (Good), measured Nov 11, 09:00 local time by 2 ground monitoring stations via OpenAQ (the median of their readings; the nearest is Worcester - Summer S, 0.4 mi (600 m) away). The main pollutant is Ozone. Air quality is satisfactory for everyone.
Is it safe to exercise outside in Worcester today?
At AQI 21 (Good): a good day to be active outside. Windows: open them to air the house. Masks: not needed. The reading changes through the day, so check again before a long run or ride.
What has the air quality in Worcester been like this week?
Over the last 7 days, the CAMS air-quality model put Worcester's daily AQI at 29 on average, from 19 on Nov 8 to an hourly peak of 64 on Nov 4. No day averaged above 100, the level where the air turns unhealthy for sensitive groups.
How much forest has the area around Worcester lost since 2001?
Since 2001, the area within 10 km of Worcester has lost about 2,980 acres (1,210 hectares) of forest (about 2,300 football fields): 6.2% of the forest it had in 2000. Most of it (80%) was deforestation, forest cleared for good, mainly for towns and roads. Forest loss has stayed about the same: about 151 acres (61 hectares) a year in 2021–2025, against 139 acres (56 hectares) a year in 2016–2020. Comparing satellite maps from 2000 and 2020, the forest around Worcester stayed about the same size, at about 52,300 acres (21,200 hectares): new forest grew on about 1,280 acres (519 hectares), and about 1,690 acres (684 hectares) were lost.
What is the tree count in Worcester?
Worcester has an estimated 84,399 trees across the 4.8 sq mi (12.51 km²) of land measured — 27.0% tree cover, 3 percentage points short of the 30% tree-cover target set for this area.
How many more trees does Worcester need?
Worcester needs roughly 9,378 more trees to close a 3-point shortfall against its 30% tree-cover target — about 206.3 t of extra CO₂ absorbed per year once grown.
How are Worcester's air quality and tree cover measured?
Air quality is measured by ground monitoring stations near Central Business District, via OpenAQ; the 7-day trend is the Open-Meteo / CAMS model's estimate. Tree cover is measured from Sentinel-2 L2A (ESA Copernicus) via Earth Search satellite imagery at 10 m detail across a 1.2 mi (2 km) radius around Central Business District; the tree count is an estimate derived from that cover.
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