Air quality comparison · Eritrea, 71 km apart
Asmara vs Keren Air quality index (AQI) today
Asmara has cleaner air than Keren right now: AQI 18 (Good) against 19 (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, both averaged AQI 40. Asmara has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Asmara18Keren19
Head to head
Asmara vs Keren at a glance
Asmara is ahead on 4 of 5 measures, and Keren on 0. The better figure in each row is marked.
| Asmara | Keren | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 18 (better) | 19 |
| PM2.5Fine particles, µg/m³. | 2.6 (better) | 3.1 |
| Past week's averageUS AQI, 7 days. | 40 | 40 |
| Tree coverWithin 2 km of the center. | 4.3% (better) | 3.7% |
| Trees still neededTo reach a healthy canopy. | 80.7K (better) | 82.6K |
Air quality today
What is the air like in Asmara and Keren right now?
Asmara has cleaner air than Keren right now: AQI 18 (Good) against 19 (Good). PM2.5 is setting the index in both.
Both readings are model estimates, with no ground station close enough to either.
AsmaraKeren
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).
Asmara: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
Keren: 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, both averaged AQI 40. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- Asmara3Keren4
- Average AQI
- Asmara40Keren40
- Worst day, AQI
- Asmara55Keren49
The daily numbers (7 days)
| Day | Asmara | Keren |
|---|---|---|
| Nov 5 | 55 | 49 |
| Nov 6 | 51 | 47 |
| Nov 7 | 40 | 38 |
| Nov 8 | 49 | 40 |
| Nov 9 | 41 | 45 |
| Nov 10 | 27 | 38 |
| Nov 11 | 18 | 22 |
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 Asmara and Keren 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 Asmara and Keren compare with the rest of the world?
Right now Asmara's air is cleaner than 90% of the 5,420 places Airleaf tracks, and Keren's is cleaner than 89%. Within Eritrea, that is 100% and 75% of its 5 measured places.
Cleaner air than…
- Asmara
- Beats 90%
- Keren
- Beats 89%
More tree cover than…
- Asmara
- Beats 9%
- Keren
- 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.
Asmara
2017: satellite photo from January 2017 of a 5 × 5 km area in the city center.
Keren
2017: satellite photo from June 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Asmara or Keren?
Asmara has more tree cover: 4.3% of the land within 2 km of its center against 3.7% around Keren, or about 13,509 trees against 11,624.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Asmara | Keren | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 13.5K (better) | 11.6K |
| Trees still neededTo reach the target. Fewer is better. | 80.7K (better) | 82.6K |
| CO₂ absorbed each yearBy the trees already standing. | 297K kg (better) | 256K 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
Asmara vs Keren: your questions answered
Is Asmara cleaner than Keren?
On air quality, yes, right now: Asmara reads AQI 18 against 19, a gap of 1 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, both averaged AQI 40.
Is it safe to exercise outdoors in Asmara and Keren today?
The advice is the same for both today. Air quality is satisfactory for everyone. Asmara reads AQI 18 and Keren reads AQI 19.
Which has more trees, Asmara or Keren?
Asmara has more tree cover: 4.3% of the land within 2 km of its center against 3.7% around Keren, or about 13,509 trees against 11,624. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Asmara and Keren need?
Asmara needs about 80,739 more to reach its canopy target of 30%, and Keren about 82,624 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Asmara and Keren 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 Asmara vs Keren 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 14, 2026 and Sep 14, 2026), and the forest figures are published yearly.
Keep going
Compare them with somewhere else
Build your own
Compare Asmara with somewhere else
This place
Asmara