Air quality comparison · El Salvador, 52 km apart
San Salvador vs Santa Ana Air quality index (AQI) today
Santa Ana has cleaner air than San Salvador right now: AQI 21 (Good) against 28 (Good).
Both sit in the same EPA band, so the health advice is the same for each today. Over the past 7 days, on modeled daily averages, Santa Ana averaged AQI 51 against 57, and it was the cleaner of the two on 6 of those days. Santa Ana has lost more forest since 2001. Santa Ana has more tree cover.
El Salvador
AQI 28
Good
Cleaner right now
- PM2.5
- 4.9 µg/m³
- Main pollutant
- PM2.5
- Source
- Model estimate
- Reading
- Nov 10, 13:00 local
El Salvador
AQI 21
Good
Cleaner right now
- PM2.5
- 3.4 µg/m³
- Main pollutant
- PM2.5
- Source
- Model estimate
- Reading
- Nov 10, 14:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
San Salvador28Santa Ana21
Head to head
San Salvador vs Santa Ana at a glance
Santa Ana is ahead on 4 of 6 measures, and San Salvador on 1. The better figure in each row is marked.
| San Salvador | Santa Ana | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 28 | 21 (better) |
| PM2.5Fine particles, µg/m³. | 4.9 | 3.4 (better) |
| Past week's averageUS AQI, 7 days. | 57 | 51 (better) |
| Forest lost since 2001Within 10 km of the center. | 869 ha (better) | 3,020 ha |
| Tree coverWithin 2 km of the center. | 36.9% | 37.2% (better) |
| Trees still neededTo reach a healthy canopy. | 0 | 0 |
Air quality today
What is the air like in San Salvador and Santa Ana right now?
Santa Ana has cleaner air than San Salvador right now: AQI 21 (Good) against 28 (Good). PM2.5 is setting the index in both.
Both readings are model estimates, with no ground station close enough to either.
San SalvadorSanta Ana
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).
San Salvador: Estimate · model corrected with 7 station cities within 245 km, e.g. Villa Nueva and Guatemala City. Data: Open-Meteo / CAMS, corrected with 7 ground-station cities within 245 km, US EPA index.
Santa Ana: Estimate · model corrected with 7 station cities within 250 km, e.g. Villa Nueva and Guatemala City. Data: Open-Meteo / CAMS, corrected with 7 ground-station cities within 250 km, US EPA index.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Santa Ana averaged AQI 51 against 57, and it was the cleaner of the two on 6 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
- San Salvador1Santa Ana6
- Average AQI
- San Salvador57Santa Ana51
- Worst day, AQI
- San Salvador72Santa Ana56
The daily numbers (7 days)
| Day | San Salvador | Santa Ana |
|---|---|---|
| Nov 4 | 57 | 56 |
| Nov 5 | 46 | 53 |
| Nov 6 | 68 | 56 |
| Nov 7 | 72 | 55 |
| Nov 8 | 50 | 47 |
| Nov 9 | 50 | 44 |
| Nov 10 | 57 | 47 |
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 San Salvador and Santa Ana today?
Air quality is satisfactory for everyone. Both are in the same EPA band today (Good), so the advice is the same.
Exercise outdoors
A good day to be active outside.
Windows
Open them to air the house.
Masks
Not needed.
Air purifier
Not needed.
Against everywhere else
How do San Salvador and Santa Ana compare with the rest of the world?
Right now San Salvador's air is cleaner than 82% of the 5,420 places Airleaf tracks, and Santa Ana's is cleaner than 88%. Within El Salvador, that is 83% and 100% of its 7 measured places.
Cleaner air than…
- San Salvador
- Beats 82%
- Santa Ana
- Beats 88%
More tree cover than…
- San Salvador
- Beats 80%
- Santa Ana
- Beats 80%
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, San Salvador or Santa Ana?
Santa Ana has lost more: about 3,020 ha of forest within 10 km of its center from 2001 to 2025, against 869 ha around San Salvador. 3,020 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: 2017, with 61 ha lost.
Worst year: 2016, with 480 ha lost.
| San Salvador | Santa Ana | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 869 ha (better) | 3,020 ha |
| Share of its forestOf what it had in 2000. | 5.2% (better) | 16% |
| Cleared for goodTurned into farms, mines or towns. | 849 ha (better) | 3,020 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Slowing down |
| Main known cause | Towns and roads (70%) | Farms, pasture and plantations (88%) |
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.
San Salvador
2017: satellite photo from January 2017 of a 5 × 5 km area about 7 km north of the city center.
Santa Ana
2017: satellite photo from January 2017 of a 5 × 5 km area about 6 km west of the city center.
Trees
Which has more trees, San Salvador or Santa Ana?
Santa Ana has more tree cover: 37.2% of the land within 2 km of its center against 36.9% around San Salvador, or about 116,867 trees against 115,925.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| San Salvador | Santa Ana | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 116K | 117K (better) |
| Trees still neededTo reach the target. Fewer is better. | 0 | 0 |
| CO₂ absorbed each yearBy the trees already standing. | 2.6M kg | 2.6M kg (better) |
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
San Salvador vs Santa Ana: your questions answered
Is Santa Ana cleaner than San Salvador?
On air quality, yes, right now: Santa Ana reads AQI 21 against 28, a gap of 7 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, Santa Ana averaged AQI 51 against 57, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in San Salvador and Santa Ana today?
The advice is the same for both today. Air quality is satisfactory for everyone. San Salvador reads AQI 28 and Santa Ana reads AQI 21.
Which has lost more forest, San Salvador or Santa Ana?
Santa Ana has lost more: about 3,020 ha of forest within 10 km of its center from 2001 to 2025, against 869 ha around San Salvador. 3,020 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, San Salvador or Santa Ana?
Santa Ana has more tree cover: 37.2% of the land within 2 km of its center against 36.9% around San Salvador, or about 116,867 trees against 115,925. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do San Salvador and Santa Ana need?
San Salvador needs about 0 more to reach its canopy target of 30%, and Santa Ana about 0 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Why can two places 52 km apart read differently?
Air changes over short distances with traffic, industry, wind and hills, and each reading comes from the nearest ground stations or, where there are none, from a regional model. A gap of a few points between neighbors is within normal variation, while a gap that crosses an EPA band is worth noticing.
Are San Salvador and Santa Ana 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 San Salvador vs Santa Ana 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 12, 2026 and Sep 17, 2026), and the forest figures are published yearly.
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