Worst air pollution Yokohama, today and tomorrow
Today (21 September): Air quality in Yokohama is very poor. AQI and NO2 are very poor; PM1 is moderate; PM2.5, PM10, and SO2 are fair; O3, CO, and HCHO are good. Pollution peaks around 1:00 PM (NO2: 85.9/100).
Tomorrow (22 September 2026): Air quality in Yokohama is very poor. PM2.5 increases to moderate; PM10 increases to moderate; PM1 increases to poor; all other pollutants stay as today. Pollution peaks around 5:00 PM (NO2: 100/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Yokohama's air quality benefits from its exceptional Tokyo Bay and Pacific Ocean coastal position, with consistent Pacific sea breezes and Tokyo Bay maritime influence providing reliable ventilation. Vehicle traffic on the Bayshore Route expressway and the surrounding Keihin industrial corridor and major container port contribute local sources, while the outstanding coastal exposure provides better conditions than the enclosed Tokyo metropolitan inland areas and summer photochemical ozone from the broader Kanto metropolitan corridor is the primary warm-season concern.
Today - 21 September | Pollution peaks at 13:00
AQI:
Very poor
85.9/100
PM2.5 (fine particles):
Fair
32.6/100
PM10 (coarse particles):
Fair
28.5/100
NO2 (nitrogen dioxide):
Very poor
85.9/100
O3 (ozone):
Good
5.4/100
SO2 (sulfur dioxide):
Fair
24.2/100
CO (carbon monoxide):
Good
0.9/100
HCHO (formaldehyde):
Good
5.1/100
PM1 (ultrafine particles):
Moderate
51.7/100
Levels show the poorest local air quality during the day
Tomorrow - 22 September | Pollution peaks at 17:00
AQI:
Very poor
100/100
PM2.5 (fine particles):
Moderate
44.3/100
PM10 (coarse particles):
Moderate
42.5/100
NO2 (nitrogen dioxide):
Very poor
100/100
O3 (ozone):
Good
6.8/100
SO2 (sulfur dioxide):
Fair
37.8/100
CO (carbon monoxide):
Good
1.6/100
HCHO (formaldehyde):
Good
7.7/100
PM1 (ultrafine particles):
Poor
72.6/100
Frequently Asked Questions
Is air quality bad in Yokohama right now?
On 21 September 2026, overall air quality in Yokohama is very poor. AQI is the main air quality indicator at 85.9/100. Pollution peaks around 1:00 PM (NO2: 85.9/100).
Will air quality be worse tomorrow in Yokohama?
On 22 September 2026, air quality conditions in Yokohama will be similar to today, with AQI forecast at very poor at 100/100. Pollution peaks around 5:00 PM (NO2: 100/100).
When is air pollution at its worst in Yokohama?
The biggest local contributors to pollution in Yokohama are traffic emissions, heavy industry such as steel, cement, or petrochemical processing, and port and shipping activity, particularly once dry spells bring strong winds. Dust carried on these winds adds substantially to particulate levels. Strong sunlight reacting with local emissions drives up ground-level ozone.
Are air quality levels in Yokohama based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 22 September 2026 at 02:59 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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