Yokohama Air Quality Forecast - Today, Tomorrow
Air Quality Today
Today (15 October): Air quality in Yokohama is moderate. AQI and NO2 are moderate; PM1 is fair; PM2.5, PM10, O3, SO2, CO, and HCHO are good. Pollution peaks around 5:00 PM (NO2: 81.1/100).
Air Quality Tomorrow
Tomorrow (16 October 2026): Air quality in Yokohama is poor. AQI worsens to poor; PM2.5 increases to fair; PM10 increases to fair; NO2 increases to poor; SO2 increases to fair; PM1 increases to moderate; all other pollutants stay as today. Pollution peaks around 3:00 PM (NO2: 100/100).
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Air Quality
Today - 15 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Moderate | 53.4/100 |
| PM2.5 (fine particles) | Good | 16.5/100 |
| PM10 (coarse particles) | Good | 16.8/100 |
| NO2 (nitrogen dioxide) | Moderate | 53.2/100 |
| O3 (ozone) | Good | 5.7/100 |
| SO2 (sulfur dioxide) | Good | 15.2/100 |
| CO (carbon monoxide) | Good | 0.8/100 |
| HCHO (formaldehyde) | Good | 2.1/100 |
| PM1 (ultrafine particles) | Fair | 33.9/100 |
Tomorrow - 16 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Poor | 74.3/100 |
| PM2.5 (fine particles) | Fair | 36.7/100 |
| PM10 (coarse particles) | Fair | 36.0/100 |
| NO2 (nitrogen dioxide) | Poor | 74.3/100 |
| O3 (ozone) | Good | 2.7/100 |
| SO2 (sulfur dioxide) | Fair | 33.9/100 |
| CO (carbon monoxide) | Good | 1.1/100 |
| HCHO (formaldehyde) | Good | 4.4/100 |
| PM1 (ultrafine particles) | Moderate | 52.3/100 |
Local Environmental Conditions
The center of Yokohama is largely built up, so vehicle exhaust and urban activity dominate the local air pollution sources. Its position by the Tokyo Bay brings breezes that often clear pollutants away. Local sources include port and shipping activity. Home heating, especially wood stoves and fireplaces, adds smoke and fine particles in the colder months. Pollution carried in from the wider region can also raise levels at times.
Fine particle levels climb from December to February, as home heating and traffic combine with cold, still air averaging 3°C. Ozone is the main concern from June to September, when sunny days averaging 27°C turn traffic and other emissions into ozone by mid-afternoon. Overall, breezy weather in April, with winds near 15 km/h, tends to sweep pollution away.
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Frequently Asked Questions About Air Quality in Kanagawa
Is air quality bad in Yokohama right now?
On 15 October 2026, overall air quality in Yokohama is moderate. AQI is the main air quality indicator at 53.4/100. Pollution peaks around 5:00 PM (NO2: 81.1/100).
Will air quality be worse tomorrow in Yokohama?
On 16 October 2026, air quality conditions in Yokohama will be worse than today, with AQI forecast at poor at 74.3/100. Pollution peaks around 3:00 PM (NO2: 100/100).
When is air pollution at its worst in Yokohama?
Fine particle levels climb from December to February, as home heating and traffic combine with cold, still air averaging 3°C. Ozone is the main concern from June to September, when sunny days averaging 27°C turn traffic and other emissions into ozone by mid-afternoon. Overall, breezy weather in April, with winds near 15 km/h, tends to sweep pollution away.
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.
Understanding the Scale
The 0–100 air quality scores represent risk levels, not direct air pollutant concentrations. Higher scores indicate higher risk.
Air Quality
| Good | 0-20 | Low air quality risk. Air quality is expected to be good, with low levels of pollution. |
| Fair | 20-40 | Generally low air quality risk. Air quality is expected to be acceptable, with some pollution present. |
| Moderate | 40-60 | Moderate air quality risk. Air pollution is elevated and air quality may be less favorable. |
| Poor | 60-80 | High air quality risk. Air pollution is high and air quality is expected to be poor. |
| Very Poor | 80-100 | Very high air quality risk. Air pollution is very high and air quality is expected to be very poor. |