Chemnitz vs Erlangen
Tree cover and air quality for both, measured the same way: Sentinel-2 imagery at 10 m detail over a 2 km radius from each city centre, and the live US EPA air quality index. Same radius and same index, so the two numbers compare directly.
Chemnitz has more tree cover — 57.3% against 50.7%.
Erlangen has cleaner air right now — AQI 44 against 56.
- Tree cover gap
- 6.6 points
- Chemnitz is ahead.
- Air quality gap
- 12 AQI
- Erlangen is cleaner.
- Trees between them
- 19.8K
- Chemnitz has more standing.
Tree cover
Share of the 2 km radius under canopy.
57.3%
50.7%
Air quality index
US EPA index, live, with its band. Lower is better.
56 · Moderate
44 · Good
Trees standing
Estimated from the measured canopy area.
179K
159K
Trees still needed
To reach the same canopy target. Fewer is better.
0
0
CO₂ absorbed each year
By the trees already standing.
3.9M kg
3.5M kg
Air quality in detail
What each city is breathing
Concentrations in µg/m³, measured at the same moment as the index above. Lower is better in every row. Erlangen is read from nearby ground stations and Chemnitz is modelled — worth knowing, since the two are not quite like for like.
PM2.5
Fine particles, the pollutant that usually sets the index.
14.6 µg/m³
10.5 µg/m³
Nitrogen dioxide
Mostly traffic and combustion.
6.9 µg/m³
5.1 µg/m³
Ozone
Forms in sunlight; peaks on hot, still afternoons.
46 µg/m³
69.1 µg/m³
The last week, day by day
A single reading can catch a city on a bad afternoon. The week says whether it was the weather or the place.
| Day | Chemnitz | Erlangen |
|---|---|---|
| 22 Sept | 28 | 31 |
| 23 Sept | 38 | 33 |
| 24 Sept | 32 | 41 |
| 25 Sept | 33 | 38 |
| 26 Sept | 37 | 49 |
| 27 Sept | 53 | 42 |
Reading these numbers
What is actually being measured
Tree cover
The share of ground under canopy inside a 2 km radius of each city centre, read from Sentinel-2 satellite imagery at 10 m detail. It is a measurement of that circle, not of the whole municipality — which is exactly what makes the two comparable, since city boundaries are drawn to wildly different rules around the world. Chemnitz leads here at 57.3%.
Air quality index
The live US EPA index, computed from current pollutant concentrations — ground stations where a city has them nearby, and a model everywhere else. It moves hour to hour, so this is a snapshot rather than a verdict on either place: Chemnitz reads 56 (moderate) and Erlangen reads 44 (good) right now.
Frequently asked
Chemnitz and Erlangen, answered
Which has more trees, Chemnitz or Erlangen?
Chemnitz, with roughly 179,113 trees inside its 2 km radius against 159,279. Tree cover tells a slightly different story from raw count: Chemnitz has the denser canopy at 57.3%.
Which has better air quality, Chemnitz or Erlangen?
Erlangen right now, at AQI 44 against 56 — a gap of 12 points. This is a live reading rather than an annual average, so it can reverse within a day.
How many more trees does each city need?
Chemnitz needs about 0 more to reach its canopy target, and Erlangen about 0. The target is the same share of ground for both, so the figures are directly comparable.
Are these two measured the same way?
Yes — that is the point of the page. Identical radius, identical satellite source at 10 m detail, and the same US EPA index for air. Nothing here is adjusted for population, city limits or climate, so the numbers describe the same-sized circle of ground in each place.
Keep going
Other comparisons nearby
Build your own
Compare Chemnitz with somewhere else
This place
Chemnitz
Want a different pair? Browse comparisons or measure any address.