Air quality
Air quality in Walnut Creek today
Updated
Moderate (US AQI 77) Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. Model estimate for Sun, Oct 25, 3:52 pm (22:52 UTC).
Live AQI, PM2.5, PM10 and ozone for Walnut Creek, California, United States, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 77 Moderate
- PM2.5
- 18 µg/m³ 1.2× WHO 24-h guideline
- PM10
- 19 µg/m³
- Ozone
- 84 µg/m³
Air quality in Walnut Creek right now
Right now the modelled US Air Quality Index for Walnut Creek, California, United States is 77, which falls in the "Moderate" band (up to 100). Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors.
PM2.5 is 18 µg/m³, 1.2 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 19 µg/m³ against a guideline of 45; ozone is 84 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 14 µg/m³ (below the 24-hour guideline of 25).
NASA FIRMS shows 34 fire hotspots within 300 km in the last day (nearest about 13 km), but particle levels are not elevated enough to point to smoke right now.
Walnut Creek vs the rest of United States
Across 747 United States cities we track, the average US AQI right now is 50 (Good). Walnut Creek at 77 is 27 points worse than average.
It ranks 704 of 747 from cleanest to most polluted; the cleanest is Hilo (18) and the most polluted Springfield, PA (131).
For context, the median across 3,909 cities worldwide is 57.
Air quality in cities near Walnut Creek
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Concord | 9 km | 77 | Moderate | 17.6 |
| Berkeley | 19 km | 68 | Moderate | 19.4 |
| Pittsburg | 21 km | 77 | Moderate | 17.6 |
| Oakland | 21 km | 68 | Moderate | 19.4 |
| Hercules | 23 km | 68 | Moderate | 19.4 |
| Ashland | 24 km | 58 | Moderate | 13.8 |
| Richmond, CA | 25 km | 68 | Moderate | 19.4 |
| Antioch | 25 km | 77 | Moderate | 17.6 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Walnut Creek, 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
At 77, most people are fine outdoors. If you are unusually sensitive to air pollution, keep long or intense workouts to the cleaner hours shown above.
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 Walnut Creek
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS), NASA FIRMS.