Air quality comparison · Japan, 29 km apart
Tokyo vs Yokohama Air quality index (AQI) today
Yokohama has cleaner air than Tokyo right now: AQI 44 (Good) against 55 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 6 days, on modeled daily averages, both averaged AQI 73. Yokohama has lost more forest since 2001. Yokohama has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Tokyo55Yokohama44
Head to head
Tokyo vs Yokohama at a glance
Yokohama is ahead on 4 of 6 measures, and Tokyo on 1. The better figure in each row is marked.
| Tokyo | Yokohama | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 55 | 44 (better) |
| PM2.5Fine particles, µg/m³. | 11 | 8 (better) |
| Past week's averageUS AQI, 6 days. | 73 | 73 |
| Forest lost since 2001Within 10 km of the center. | 4 ha (better) | 19 ha |
| Tree coverWithin 2 km of the center. | 12.7% | 17.9% (better) |
| Trees still neededTo reach a healthy canopy. | 53.8K | 31.7K (better) |
Air quality today
What is the air like in Tokyo and Yokohama right now?
Yokohama has cleaner air than Tokyo right now: AQI 44 (Good) against 55 (Moderate). PM2.5 is setting the index in both.
Both readings come from nearby ground stations.
TokyoYokohama
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).
Tokyo: Ground station · 渋谷区本町6-6-2, 1.4 km away · median of 30 stations. Data: OpenAQ · Ministry of the Environment Air Pollutant Wide Area Monitoring System.
Yokohama: Ground station · Yokohama (横浜), 1.6 km away · median of 14 stations. Data: OpenAQ · Ministry of the Environment Air Pollutant Wide Area Monitoring System, World Air Quality Index Project, Kanagawa Prefectural Environmental Science Research Center, Environmental Monitoring Information Division (神奈川県環境科学センター 環境監視情報課), Japan Atmospheric Environmental Regional Observation System (環境省大気汚染物質広域監視システム).
The past week
Which had cleaner air over the past 6 days?
Over the past 6 days, on modeled daily averages, both averaged AQI 73. The two are close enough that the air model behind these daily figures barely separates them, so their lines nearly overlap.
- Cleaner days
- Tokyo0Yokohama1
- Average AQI
- Tokyo73Yokohama73
- Worst day, AQI
- Tokyo107Yokohama107
The daily numbers (6 days)
| Day | Tokyo | Yokohama |
|---|---|---|
| Nov 5 | 72 | 72 |
| Nov 6 | 107 | 107 |
| Nov 7 | 61 | 61 |
| Nov 8 | 68 | 68 |
| Nov 9 | 68 | 68 |
| Nov 10 | 63 | 61 |
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 Tokyo and Yokohama today?
Tokyo (AQI 55, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Yokohama (AQI 44, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Tokyo
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Yokohama
- A good day to be active outside.
Windows
- Tokyo
- Fine to open; close them if you are sensitive to pollution.
- Yokohama
- Open them to air the house.
Masks
- Tokyo
- Not needed for most people.
- Yokohama
- Not needed.
Air purifier
- Tokyo
- Worth running if you are sensitive.
- Yokohama
- Not needed.
Against everywhere else
How do Tokyo and Yokohama compare with the rest of the world?
Right now Tokyo's air is cleaner than 54% of the 5,420 places Airleaf tracks, and Yokohama's is cleaner than 66%. Within Japan, that is 2% and 22% of its 207 measured places.
Cleaner air than…
- Tokyo
- Beats 54%
- Yokohama
- Beats 66%
More tree cover than…
- Tokyo
- Beats 28%
- Yokohama
- Beats 41%
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, Tokyo or Yokohama?
Yokohama has lost more: about 19 ha of forest within 10 km of its center from 2001 to 2025, against 4 ha around Tokyo. 14 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: 2012, with 1 ha lost.
Worst year: 2004, with 3 ha lost.
| Tokyo | Yokohama | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 4 ha (better) | 19 ha |
| Share of its forestOf what it had in 2000. | under 1% (better) | 1.4% |
| Cleared for goodTurned into farms, mines or towns. | under 1 ha (better) | 14 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (23%) | Towns and roads (72%) |
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.
Tokyo
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Yokohama
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Tokyo or Yokohama?
Yokohama has more tree cover: 17.9% of the land within 2 km of its center against 12.7% around Tokyo, or about 46,956 trees against 39,499.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Tokyo | Yokohama | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 39.5K | 47.0K (better) |
| Trees still neededTo reach the target. Fewer is better. | 53.8K | 31.7K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 869K kg | 1.0M 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
Tokyo vs Yokohama: your questions answered
Is Yokohama cleaner than Tokyo?
On air quality, yes, right now: Yokohama reads AQI 44 against 55, a gap of 11 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, both averaged AQI 73.
Is it safe to exercise outdoors in Tokyo and Yokohama today?
In Tokyo, at AQI 55: Unusually sensitive people should consider limiting long outdoor exertion. In Yokohama, at AQI 44: Air quality is satisfactory for everyone.
Which has lost more forest, Tokyo or Yokohama?
Yokohama has lost more: about 19 ha of forest within 10 km of its center from 2001 to 2025, against 4 ha around Tokyo. 14 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Tokyo or Yokohama?
Yokohama has more tree cover: 17.9% of the land within 2 km of its center against 12.7% around Tokyo, or about 46,956 trees against 39,499. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Tokyo and Yokohama need?
Tokyo needs about 53,806 more to reach its canopy target of 30%, and Yokohama about 31,741 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Why can two places 29 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 Tokyo and Yokohama 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 Tokyo vs Yokohama 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 (Jul 25, 2026 and Aug 24, 2026), and the forest figures are published yearly.
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