Air quality comparison · Chile, 64 km apart
Puente Alto vs Rancagua Air quality index (AQI) today
Rancagua has cleaner air than Puente Alto right now: AQI 39 (Good) against 58 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Rancagua averaged AQI 40 against 54, and it was the cleaner of the two on 7 of those days. Rancagua has lost more forest since 2001. Puente Alto has more tree cover.
Chile
AQI 58
Moderate
Cleaner right now
- PM2.5
- 13.2 µg/m³
- Main pollutant
- PM2.5
- Source
- Model estimate
- Reading
- Nov 10, 22:00 local
Chile
AQI 39
Good
Cleaner right now
- PM2.5
- 8.2 µg/m³
- Main pollutant
- PM2.5
- Source
- Model estimate
- Reading
- Nov 10, 22:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Puente Alto58Rancagua39
Head to head
Puente Alto vs Rancagua at a glance
Puente Alto and Rancagua are level, each ahead on 3 of 6 measures. The better figure in each row is marked.
| Puente Alto | Rancagua | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 58 | 39 (better) |
| PM2.5Fine particles, µg/m³. | 13.2 | 8.2 (better) |
| Past week's averageUS AQI, 7 days. | 54 | 40 (better) |
| Forest lost since 2001Within 10 km of the center. | 38 ha (better) | 401 ha |
| Tree coverWithin 2 km of the center. | 7.9% (better) | 7.3% |
| Trees still neededTo reach a healthy canopy. | 69.4K (better) | 71.3K |
Air quality today
What is the air like in Puente Alto and Rancagua right now?
Rancagua has cleaner air than Puente Alto right now: AQI 39 (Good) against 58 (Moderate). PM2.5 is setting the index in both.
Both readings are model estimates, with no ground station close enough to either.
Puente AltoRancagua
Concentrations at the same moment as the index above, for the pollutants both places report. Lower is better. The dark marks on the PM2.5 and PM10 rows show the WHO's 24-hour guidelines (15 and 45 µg/m³).
Puente Alto: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
Rancagua: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Rancagua averaged AQI 40 against 54, and it was the cleaner of the two on 7 of those days. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- Puente Alto0Rancagua7
- Average AQI
- Puente Alto54Rancagua40
- Worst day, AQI
- Puente Alto69Rancagua56
The daily numbers (7 days)
| Day | Puente Alto | Rancagua |
|---|---|---|
| Nov 4 | 38 | 28 |
| Nov 5 | 69 | 56 |
| Nov 6 | 60 | 29 |
| Nov 7 | 45 | 35 |
| Nov 8 | 56 | 52 |
| Nov 9 | 55 | 53 |
| Nov 10 | 54 | 28 |
Daily averages from the CAMS atmospheric model for both places, so the week compares like with like. They can differ from today's reading at the top of the page wherever that comes from a ground station.
What it means today
Is it safe to go outside in Puente Alto and Rancagua today?
Puente Alto (AQI 58, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Rancagua (AQI 39, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Puente Alto
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Rancagua
- A good day to be active outside.
Windows
- Puente Alto
- Fine to open; close them if you are sensitive to pollution.
- Rancagua
- Open them to air the house.
Masks
- Puente Alto
- Not needed for most people.
- Rancagua
- Not needed.
Air purifier
- Puente Alto
- Worth running if you are sensitive.
- Rancagua
- Not needed.
Against everywhere else
How do Puente Alto and Rancagua compare with the rest of the world?
Right now Puente Alto's air is cleaner than 49% of the 5,420 places Airleaf tracks, and Rancagua's is cleaner than 70%. Within Chile, that is 23% and 77% of its 31 measured places.
Cleaner air than…
- Puente Alto
- Beats 49%
- Rancagua
- Beats 70%
More tree cover than…
- Puente Alto
- Beats 16%
- Rancagua
- Beats 15%
Includes model estimates as well as station readings, so it can differ from our most polluted and cleanest air rankings, which use station readings only.
Deforestation · 2001–2025
Which has lost more forest, Puente Alto or Rancagua?
Rancagua has lost more: about 401 ha of forest within 10 km of its center from 2001 to 2025, against 38 ha around Puente Alto. 153 ha of that was cleared for good, for farms, mines or towns.
Measured within 10 km of each center, from the yearly satellite maps of forest loss: a wider circle than the one for tree cover, because forest is usually lost at a city's edges.
Worst year: 2014, with 18 ha lost.
Worst year: 2018, with 204 ha lost.
| Puente Alto | Rancagua | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 38 ha (better) | 401 ha |
| Share of its forestOf what it had in 2000. | 1.8% (better) | 21% |
| Cleared for goodTurned into farms, mines or towns. | 14 ha (better) | 153 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Wildfires (41%) | Logging (59%) |
Satellite timelapses
Watch both change, year by year
A clear satellite photo a year of the land around each city. Press play, turn on the forest cleared since the first year, or drag the before and after.
Puente Alto
2017: satellite photo from March 2017 of a 5 × 5 km area in the city center.
Rancagua
2017: satellite photo from February 2017 of a 5 × 5 km area about 7 km southeast of the city center.
Trees
Which has more trees, Puente Alto or Rancagua?
Puente Alto has more tree cover: 7.9% of the land within 2 km of its center against 7.3% around Rancagua, or about 24,819 trees against 22,934.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Puente Alto | Rancagua | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 24.8K (better) | 22.9K |
| Trees still neededTo reach the target. Fewer is better. | 69.4K (better) | 71.3K |
| CO₂ absorbed each yearBy the trees already standing. | 546K kg (better) | 505K kg |
Tree cover on the satellite image
The same 2 km radius around each center, with the tree cover the satellite found marked on it.
Reading these numbers
How this comparison is made
Air quality index
The US EPA index, computed from current pollutant concentrations: ground stations where a place has them nearby, and the CAMS atmospheric model everywhere else. It moves hour to hour, so it is a snapshot rather than a verdict on either place. The guideline marks are from the WHO's 2021 air quality guidelines.
Trees and forest
Tree cover is the share of ground under canopy within 2 km of each center, read from Sentinel-2 satellite imagery at 10 m detail. It measures that circle, not the whole municipality, which is what makes the two comparable. Forest loss comes from the University of Maryland's Global Forest Change maps.
More on the method on the About Airleaf page.
Frequently asked
Puente Alto vs Rancagua: your questions answered
Is Rancagua cleaner than Puente Alto?
On air quality, yes, right now: Rancagua reads AQI 39 against 58, a gap of 19 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. Over the past 7 days, on modeled daily averages, Rancagua averaged AQI 40 against 54, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Puente Alto and Rancagua today?
In Puente Alto, at AQI 58: Unusually sensitive people should consider limiting long outdoor exertion. In Rancagua, at AQI 39: Air quality is satisfactory for everyone.
Which has lost more forest, Puente Alto or Rancagua?
Rancagua has lost more: about 401 ha of forest within 10 km of its center from 2001 to 2025, against 38 ha around Puente Alto. 153 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Puente Alto or Rancagua?
Puente Alto has more tree cover: 7.9% of the land within 2 km of its center against 7.3% around Rancagua, or about 24,819 trees against 22,934. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Puente Alto and Rancagua need?
Puente Alto needs about 69,429 more to reach its canopy target of 30%, and Rancagua about 71,314 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Puente Alto and Rancagua measured the same way?
The method is the same: the US EPA index for air, and Sentinel-2 satellite imagery at 10 m detail over an identical radius for trees. Both readings are model estimates, with no ground station close enough to either. Nothing is adjusted for population, city limits or climate.
How often does the Puente Alto vs Rancagua comparison update?
The air readings refresh about once an hour, and each reading's local time is shown at the top of the page. Tree cover comes from the latest clear satellite image of each area (Mar 13, 2026 and Mar 13, 2026), and the forest figures are published yearly.
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