Air quality comparison · Japan, 139 km apart
Nagoya vs Osaka Air quality index (AQI) today
Nagoya has cleaner air than Osaka right now: AQI 33 (Good) against 58 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Nagoya averaged AQI 48 against 60, and it was the cleaner of the two on 6 of those days. Nagoya has lost more forest since 2001. Nagoya has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Nagoya33Osaka58
Head to head
Nagoya vs Osaka at a glance
Nagoya is ahead on 5 of 6 measures, and Osaka on 1. The better figure in each row is marked.
| Nagoya | Osaka | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 33 (better) | 58 |
| PM2.5Fine particles, µg/m³. | 6 (better) | 13.1 |
| Past week's averageUS AQI, 7 days. | 48 (better) | 60 |
| Forest lost since 2001Within 10 km of the center. | 9 ha | 2 ha (better) |
| Tree coverWithin 2 km of the center. | 9.0% (better) | 2.7% |
| Trees still neededTo reach a healthy canopy. | 61.8K (better) | 72.0K |
Air quality today
What is the air like in Nagoya and Osaka right now?
Nagoya has cleaner air than Osaka right now: AQI 33 (Good) against 58 (Moderate). PM2.5 is setting the index in both.
Both readings come from nearby ground stations.
NagoyaOsaka
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).
Nagoya: Ground station · Nagoya (名古屋), 0 m away · median of 3 stations. Data: World Air Quality Index Project, Japan Atmospheric Environmental Regional Observation System (環境省大気汚染物質広域監視システム), Aichi air pollution continuous monitoring results (愛知県大気汚染常時監視結果).
Osaka: Ground station · Kumata, Osaka Prefecture, Japan (杭全町交差点大阪市東住吉区), 6.8 km away · median of 3 stations. Data: World Air Quality Index Project, Japan Atmospheric Environmental Regional Observation System (環境省大気汚染物質広域監視システム), Ozaka, Japan Environment Agency (大阪府 大気汚染監視).
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Nagoya averaged AQI 48 against 60, 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
- Nagoya6Osaka0
- Average AQI
- Nagoya48Osaka60
- Worst day, AQI
- Nagoya67Osaka78
The daily numbers (7 days)
| Day | Nagoya | Osaka |
|---|---|---|
| Nov 5 | 56 | 77 |
| Nov 6 | 54 | 54 |
| Nov 7 | 31 | 52 |
| Nov 8 | 44 | 54 |
| Nov 9 | 67 | 78 |
| Nov 10 | 40 | 42 |
| Nov 11 | 42 | 66 |
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 Nagoya and Osaka today?
Nagoya (AQI 33, Good): Air quality is satisfactory for everyone.
Osaka (AQI 58, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Nagoya
- A good day to be active outside.
- Osaka
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Nagoya
- Open them to air the house.
- Osaka
- Fine to open; close them if you are sensitive to pollution.
Masks
- Nagoya
- Not needed.
- Osaka
- Not needed for most people.
Air purifier
- Nagoya
- Not needed.
- Osaka
- Worth running if you are sensitive.
Against everywhere else
How do Nagoya and Osaka compare with the rest of the world?
Right now Nagoya's air is cleaner than 76% of the 5,420 places Airleaf tracks, and Osaka's is cleaner than 50%. Within Japan, that is 50% and 1% of its 207 measured places.
Cleaner air than…
- Nagoya
- Beats 76%
- Osaka
- Beats 50%
More tree cover than…
- Nagoya
- Beats 19%
- Osaka
- Beats 6%
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, Nagoya or Osaka?
Nagoya has lost more: about 9 ha of forest within 10 km of its center from 2001 to 2025, against 2 ha around Osaka. 6 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: 2010, with 2 ha lost.
Worst year: 2002, with 1 ha lost.
| Nagoya | Osaka | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 9 ha | 2 ha (better) |
| Share of its forestOf what it had in 2000. | 1.4% (better) | 1.9% |
| Cleared for goodTurned into farms, mines or towns. | 6 ha | 1 ha (better) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (67%) | Towns and roads (64%) |
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.
Nagoya
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Osaka
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Nagoya or Osaka?
Nagoya has more tree cover: 9.0% of the land within 2 km of its center against 2.7% around Osaka, or about 26,493 trees against 7,117.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Nagoya | Osaka | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 26.5K (better) | 7.1K |
| Trees still neededTo reach the target. Fewer is better. | 61.8K (better) | 72.0K |
| CO₂ absorbed each yearBy the trees already standing. | 583K kg (better) | 157K 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
Nagoya vs Osaka: your questions answered
Is Nagoya cleaner than Osaka?
On air quality, yes, right now: Nagoya reads AQI 33 against 58, a gap of 25 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, Nagoya averaged AQI 48 against 60, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in Nagoya and Osaka today?
In Nagoya, at AQI 33: Air quality is satisfactory for everyone. In Osaka, at AQI 58: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Nagoya or Osaka?
Nagoya has lost more: about 9 ha of forest within 10 km of its center from 2001 to 2025, against 2 ha around Osaka. 6 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Nagoya or Osaka?
Nagoya has more tree cover: 9.0% of the land within 2 km of its center against 2.7% around Osaka, or about 26,493 trees against 7,117. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Nagoya and Osaka need?
Nagoya needs about 61,817 more to reach its canopy target of 30%, and Osaka about 71,957 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Nagoya and Osaka 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 come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the Nagoya vs Osaka 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 (Aug 24, 2026 and Aug 25, 2026), and the forest figures are published yearly.
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