Air quality comparison · Peru, 1595 km apart
Arequipa vs Piura Air quality index (AQI) today
Piura has cleaner air than Arequipa right now: AQI 36 (Good) against 76 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Piura averaged AQI 28 against 71, and it was the cleaner of the two on 7 of those days. Arequipa has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Arequipa76Piura36
Head to head
Arequipa vs Piura at a glance
Piura is ahead on 3 of 5 measures, and Arequipa on 2. The better figure in each row is marked.
| Arequipa | Piura | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 76 | 36 (better) |
| PM2.5Fine particles, µg/m³. | 22 | 5.6 (better) |
| Past week's averageUS AQI, 7 days. | 71 | 28 (better) |
| Tree coverWithin 2 km of the center. | 5.7% (better) | 3.4% |
| Trees still neededTo reach a healthy canopy. | 76.3K (better) | 83.6K |
Air quality today
What is the air like in Arequipa and Piura right now?
Piura has cleaner air than Arequipa right now: AQI 36 (Good) against 76 (Moderate). PM2.5 is setting the index in both.
Arequipa's PM2.5 is about 1.5× the WHO's 24-hour guideline of 15 µg/m³.
Both readings are model estimates, with no ground station close enough to either.
ArequipaPiura
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).
Arequipa: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
Piura: 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, Piura averaged AQI 28 against 71, 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
- Arequipa0Piura7
- Average AQI
- Arequipa71Piura28
- Worst day, AQI
- Arequipa85Piura39
The daily numbers (7 days)
| Day | Arequipa | Piura |
|---|---|---|
| Nov 5 | 85 | 29 |
| Nov 6 | 65 | 22 |
| Nov 7 | 58 | 27 |
| Nov 8 | 67 | 24 |
| Nov 9 | 73 | 26 |
| Nov 10 | 76 | 26 |
| Nov 11 | 76 | 39 |
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 Arequipa and Piura today?
Arequipa (AQI 76, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Piura (AQI 36, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Arequipa
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Piura
- A good day to be active outside.
Windows
- Arequipa
- Fine to open; close them if you are sensitive to pollution.
- Piura
- Open them to air the house.
Masks
- Arequipa
- Not needed for most people.
- Piura
- Not needed.
Air purifier
- Arequipa
- Worth running if you are sensitive.
- Piura
- Not needed.
Against everywhere else
How do Arequipa and Piura compare with the rest of the world?
Right now Arequipa's air is cleaner than 33% of the 5,420 places Airleaf tracks, and Piura's is cleaner than 74%. Within Peru, that is 0% and 45% of its 21 measured places.
Cleaner air than…
- Arequipa
- Beats 33%
- Piura
- Beats 74%
More tree cover than…
- Arequipa
- Beats 11%
- Piura
- Beats 7%
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.
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.
Arequipa
2017: satellite photo from April 2017 of a 5 × 5 km area in the city center.
Piura
2018: satellite photo from September 2018 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Arequipa or Piura?
Arequipa has more tree cover: 5.7% of the land within 2 km of its center against 3.4% around Piura, or about 17,907 trees against 10,681.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Arequipa | Piura | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 17.9K (better) | 10.7K |
| Trees still neededTo reach the target. Fewer is better. | 76.3K (better) | 83.6K |
| CO₂ absorbed each yearBy the trees already standing. | 394K kg (better) | 235K 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
Arequipa vs Piura: your questions answered
Is Piura cleaner than Arequipa?
On air quality, yes, right now: Piura reads AQI 36 against 76, a gap of 40 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, Piura averaged AQI 28 against 71, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Arequipa and Piura today?
In Arequipa, at AQI 76: Unusually sensitive people should consider limiting long outdoor exertion. In Piura, at AQI 36: Air quality is satisfactory for everyone.
Which has more trees, Arequipa or Piura?
Arequipa has more tree cover: 5.7% of the land within 2 km of its center against 3.4% around Piura, or about 17,907 trees against 10,681. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Arequipa and Piura need?
Arequipa needs about 76,341 more to reach its canopy target of 30%, and Piura about 83,566 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Arequipa and Piura 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 Arequipa vs Piura 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 (Sep 15, 2026 and Sep 15, 2026), and the forest figures are published yearly.
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