Air quality comparison · Algeria, 37 km apart
Algiers vs Blida Air quality index (AQI) today
Blida has cleaner air than Algiers right now: AQI 54 (Moderate) against 70 (Moderate).
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, Blida averaged AQI 38 against 56, and it was the cleaner of the two on 7 of those days. Blida has lost more forest since 2001. Blida has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Algiers70Blida54
Head to head
Algiers vs Blida at a glance
Blida is ahead on 5 of 6 measures, and Algiers on 1. The better figure in each row is marked.
| Algiers | Blida | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 70 | 54 (better) |
| PM2.5Fine particles, µg/m³. | 21.8 | 11.7 (better) |
| Past week's averageUS AQI, 7 days. | 56 | 38 (better) |
| Forest lost since 2001Within 10 km of the center. | 70 ha (better) | 1,410 ha |
| Tree coverWithin 2 km of the center. | 14.8% | 27.5% (better) |
| Trees still neededTo reach a healthy canopy. | 47.2K | 7.9K (better) |
Air quality today
What is the air like in Algiers and Blida right now?
Blida has cleaner air than Algiers right now: AQI 54 (Moderate) against 70 (Moderate). PM2.5 is setting the index in both.
Algiers'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.
AlgiersBlida
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).
Algiers: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
Blida: 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, Blida averaged AQI 38 against 56, 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
- Algiers0Blida7
- Average AQI
- Algiers56Blida38
- Worst day, AQI
- Algiers64Blida44
The daily numbers (7 days)
| Day | Algiers | Blida |
|---|---|---|
| Nov 4 | 56 | 32 |
| Nov 5 | 47 | 36 |
| Nov 6 | 52 | 35 |
| Nov 7 | 55 | 41 |
| Nov 8 | 58 | 37 |
| Nov 9 | 57 | 39 |
| Nov 10 | 64 | 44 |
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 Algiers and Blida today?
Unusually sensitive people should consider limiting long outdoor exertion. Both are in the same EPA band today (Moderate), so the advice is the same.
Exercise outdoors
Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
Fine to open; close them if you are sensitive to pollution.
Masks
Not needed for most people.
Air purifier
Worth running if you are sensitive.
Against everywhere else
How do Algiers and Blida compare with the rest of the world?
Right now Algiers's air is cleaner than 38% of the 5,420 places Airleaf tracks, and Blida's is cleaner than 55%. Within Algeria, that is 0% and 23% of its 40 measured places.
Cleaner air than…
- Algiers
- Beats 38%
- Blida
- Beats 55%
More tree cover than…
- Algiers
- Beats 34%
- Blida
- Beats 63%
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, Algiers or Blida?
Blida has lost more: about 1,410 ha of forest within 10 km of its center from 2001 to 2025, against 70 ha around Algiers. 190 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: 2019, with 7 ha lost.
Worst year: 2025, with 371 ha lost.
| Algiers | Blida | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 70 ha (better) | 1,410 ha |
| Share of its forestOf what it had in 2000. | 12% (better) | 12% |
| Cleared for goodTurned into farms, mines or towns. | 66 ha (better) | 190 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Speeding up |
| Main known cause | Towns and roads (82%) | Wildfires (85%) |
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.
Algiers
2017: satellite photo from September 2017 of a 5 × 5 km area in the city center.
Blida
2017: satellite photo from September 2017 of a 5 × 5 km area about 3 km southeast of the city center.
Trees
Which has more trees, Algiers or Blida?
Blida has more tree cover: 27.5% of the land within 2 km of its center against 14.8% around Algiers, or about 86,394 trees against 45,984.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Algiers | Blida | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 46.0K | 86.4K (better) |
| Trees still neededTo reach the target. Fewer is better. | 47.2K | 7.9K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.0M kg | 1.9M 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
Algiers vs Blida: your questions answered
Is Blida cleaner than Algiers?
On air quality, yes, right now: Blida reads AQI 54 against 70, a gap of 16 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, Blida averaged AQI 38 against 56, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Algiers and Blida today?
The advice is the same for both today. Unusually sensitive people should consider limiting long outdoor exertion. Algiers reads AQI 70 and Blida reads AQI 54.
Which has lost more forest, Algiers or Blida?
Blida has lost more: about 1,410 ha of forest within 10 km of its center from 2001 to 2025, against 70 ha around Algiers. 190 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Algiers or Blida?
Blida has more tree cover: 27.5% of the land within 2 km of its center against 14.8% around Algiers, or about 86,394 trees against 45,984. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Algiers and Blida need?
Algiers needs about 47,227 more to reach its canopy target of 30%, and Blida about 7,854 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Why can two places 37 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 Algiers and Blida 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 Algiers vs Blida 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.
Keep going
Compare them with somewhere else
Build your own
Compare Algiers with somewhere else
This place
Algiers