Air quality comparison · Tanzania, 807 km apart
Mwanza vs Zanzibar Air quality index (AQI) today
Mwanza has cleaner air than Zanzibar right now: AQI 21 (Good) against 43 (Good).
Both sit in the same EPA band, so the health advice is the same for each today. Over the past 6 days, on modeled daily averages, Mwanza averaged AQI 36 against 49, and it was the cleaner of the two on 6 of those days. Zanzibar has lost more forest since 2001. Mwanza has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Mwanza21Zanzibar43
Head to head
Mwanza vs Zanzibar at a glance
Mwanza is ahead on 6 of 6 measures, and Zanzibar on 0. The better figure in each row is marked.
| Mwanza | Zanzibar | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 21 (better) | 43 |
| PM2.5Fine particles, µg/m³. | 3.2 (better) | 7.3 |
| Past week's averageUS AQI, 6 days. | 36 (better) | 49 |
| Forest lost since 2001Within 10 km of the center. | 28 ha (better) | 1,700 ha |
| Tree coverWithin 2 km of the center. | 23.5% (better) | 19.8% |
| Trees still neededTo reach a healthy canopy. | 15.6K (better) | 19.7K |
Air quality today
What is the air like in Mwanza and Zanzibar right now?
Mwanza has cleaner air than Zanzibar right now: AQI 21 (Good) against 43 (Good). PM2.5 is setting the index in both.
Both readings are model estimates, with no ground station close enough to either.
MwanzaZanzibar
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).
Mwanza: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
Zanzibar: Model estimate · no ground station nearby. Data: Open-Meteo / CAMS, US EPA index.
The past week
Which had cleaner air over the past 6 days?
Over the past 6 days, on modeled daily averages, Mwanza averaged AQI 36 against 49, 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
- Mwanza6Zanzibar0
- Average AQI
- Mwanza36Zanzibar49
- Worst day, AQI
- Mwanza48Zanzibar53
The daily numbers (6 days)
| Day | Mwanza | Zanzibar |
|---|---|---|
| Nov 5 | 33 | 39 |
| Nov 6 | 48 | 51 |
| Nov 7 | 42 | 50 |
| Nov 8 | 48 | 53 |
| Nov 9 | 25 | 52 |
| Nov 10 | 20 | 49 |
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 Mwanza and Zanzibar 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 Mwanza and Zanzibar compare with the rest of the world?
Right now Mwanza's air is cleaner than 88% of the 5,420 places Airleaf tracks, and Zanzibar's is cleaner than 67%. Within Tanzania, that is 94% and 64% of its 34 measured places.
Cleaner air than…
- Mwanza
- Beats 88%
- Zanzibar
- Beats 67%
More tree cover than…
- Mwanza
- Beats 55%
- Zanzibar
- Beats 46%
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, Mwanza or Zanzibar?
Zanzibar has lost more: about 1,700 ha of forest within 10 km of its center from 2001 to 2025, against 28 ha around Mwanza. 1,700 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: 2007, with 10 ha lost.
Worst year: 2011, with 229 ha lost.
| Mwanza | Zanzibar | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 28 ha (better) | 1,700 ha |
| Share of its forestOf what it had in 2000. | 10% (better) | 23% |
| Cleared for goodTurned into farms, mines or towns. | 24 ha (better) | 1,700 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Holding steady |
| Main known cause | Towns and roads (53%) | Towns and roads (91%) |
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.
Mwanza
2017: satellite photo from June 2017 of a 5 × 5 km area in the city center.
Zanzibar
2017: satellite photo from July 2017 of a 5 × 5 km area about 7 km east of the city center.
Trees
Which has more trees, Mwanza or Zanzibar?
Mwanza has more tree cover: 23.5% of the land within 2 km of its center against 19.8% around Zanzibar, or about 56,256 trees against 38,317.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Mwanza | Zanzibar | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 56.3K (better) | 38.3K |
| Trees still neededTo reach the target. Fewer is better. | 15.6K (better) | 19.7K |
| CO₂ absorbed each yearBy the trees already standing. | 1.2M kg (better) | 843K 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
Mwanza vs Zanzibar: your questions answered
Is Mwanza cleaner than Zanzibar?
On air quality, yes, right now: Mwanza reads AQI 21 against 43, a gap of 22 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 6 days, on modeled daily averages, Mwanza averaged AQI 36 against 49, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in Mwanza and Zanzibar today?
The advice is the same for both today. Air quality is satisfactory for everyone. Mwanza reads AQI 21 and Zanzibar reads AQI 43.
Which has lost more forest, Mwanza or Zanzibar?
Zanzibar has lost more: about 1,700 ha of forest within 10 km of its center from 2001 to 2025, against 28 ha around Mwanza. 1,700 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Mwanza or Zanzibar?
Mwanza has more tree cover: 23.5% of the land within 2 km of its center against 19.8% around Zanzibar, or about 56,256 trees against 38,317. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Mwanza and Zanzibar need?
Mwanza needs about 15,560 more to reach its canopy target of 30%, and Zanzibar about 19,739 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Mwanza and Zanzibar 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 Mwanza vs Zanzibar 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 17, 2026 and Sep 16, 2026), and the forest figures are published yearly.
Keep going
Compare them with somewhere else
Build your own
Compare Mwanza with somewhere else
This place
Mwanza