Air quality
Air quality in Yamagata today
Updated
Good (US AQI 25) Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. Model estimate for Mon, Oct 26, 9:00 am (00:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Yamagata, Japan, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 25 Good
- PM2.5
- 12 µg/m³ 0.8× WHO 24-h guideline
- PM10
- 16 µg/m³
- Ozone
- 67 µg/m³
- Dominant pollutant
- PM2.5 sub-index 25
- Best hour today
- 9:00 am AQI 25
- European AQI
- 34
Air quality in Yamagata right now
Right now the modelled US Air Quality Index for Yamagata, Japan is 25, which falls in the "Good" band (up to 50). Air quality is satisfactory and poses little or no risk; a good time for outdoor activity.
The index is driven mainly by PM2.5, whose own sub-index is 25. Fine and coarse particles come from traffic, heating, industry, dust and smoke; they build up on calm nights and clear when wind or rain arrives.
PM2.5 is 12 µg/m³, within the WHO 24-hour guideline of 15 µg/m³; PM10 is 16 µg/m³ against a guideline of 45; ozone is 67 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 3 µg/m³ (below the 24-hour guideline of 25).
Also this hour: UV index 1.3, carbon monoxide 135 µg/m³.
Yamagata AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 25 around Mon 9:00 am to 49 around Tue 12:00 am, staying "Good" throughout.
The following day is expected to be cleaner, averaging about 37 against 42 for the next 24 hours.
| Local time (Asia/Tokyo) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Mon 9:00 am | 25 | Good | 12.1 | 16 | 67 |
| Mon 12:00 pm | 31 | Good | 13.9 | 19 | 69 |
| Mon 3:00 pm | 39 | Good | 8.8 | 12 | 65 |
| Mon 6:00 pm | 42 | Good | 5.3 | 7 | 60 |
| Mon 9:00 pm | 45 | Good | 7.5 | 10 | 55 |
| Tue 12:00 am | 49 | Good | 6.6 | 9 | 54 |
| Tue 3:00 am | 49 | Good | 5.4 | 7 | 54 |
| Tue 6:00 am | 47 | Good | 5 | 7 | 59 |
| Tue 9:00 am | 42 | Good | 3.6 | 5 | 62 |
| Tue 12:00 pm | 36 | Good | 1.5 | 2 | 77 |
| Tue 3:00 pm | 33 | Good | 4.7 | 8 | 88 |
| Tue 6:00 pm | 37 | Good | 7.7 | 11 | 81 |
| Tue 9:00 pm | 38 | Good | 5.6 | 7 | 69 |
| Wed 12:00 am | 36 | Good | 4.8 | 7 | 86 |
| Wed 3:00 am | 36 | Good | 4.7 | 7 | 79 |
| Wed 6:00 am | 37 | Good | 4 | 6 | 82 |
| Wed 9:00 am | 38 | Good | 3.6 | 5 | 81 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Yamagata today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 9:00 am (AQI 25, Good) and the worst around 9:00 pm (AQI 45). That is a swing of 20 points, so a run or walk around 9:00 am is noticeably better.
Yamagata vs the rest of Japan
Across 176 Japan cities we track, the average US AQI right now is 47 (Good). Yamagata at 25 is 22 points cleaner than average.
For context, the median across 3,556 cities worldwide is 58.
Air quality in cities near Yamagata
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Sendai | 44 km | 34 | Good | 11.7 |
| Date | 48 km | 23 | Good | 9.7 |
| Fukushima | 54 km | 23 | Good | 9.7 |
| Kōriyama | 93 km | 33 | Good | 8.3 |
| Niigata | 121 km | 46 | Good | 9.1 |
| Iwaki | 139 km | 52 | Moderate | 10.9 |
| Akita | 166 km | 46 | Good | 6.2 |
| Morioka | 177 km | 34 | Good | 6.3 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Yamagata, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Advice for sensitive groups
With the AQI at 25, there is no need for sensitive groups to change plans. People with asthma should still carry their reliever inhaler as usual.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Yamagata
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).