Air quality
We use data from multiple reporters to estimate air quality in the grid cell around your location. You'll see:
- Pollutant values (converted to
µg/m³) — helpful for detail and comparisons. - AQI-style scores (0–500 scale) — easier to interpret at a glance: Good, Moderate, Unhealthy, and so on.
Under the hood, each reporter gives us raw measurements or model estimates. We map those into the cell that covers your device or saved place, then compute scores and charts over time.
Sources
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Cells
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Scores & Charts
Pollutants
| Pollutant | Units | Bands | Short-term effects |
|---|---|---|---|
Fine particles (PM2.5)(PM2.5)Tiny particles smaller than 2.5µm. They can penetrate deep into the lungs and even enter the bloodstream. | µg/m³ | Good0–12Moderate12–35Unhealthy for Sensitive35–55Unhealthy55–150Very Unhealthy150–250Hazardous250+ | Can cause coughing, chest tightness, shortness of breath, and reduced exercise tolerance. |
Coarse particles (PM10)(PM10)Dust, pollen fragments, and larger smoke particles. They irritate the upper airways and eyes. | µg/m³ | Good0–54Moderate55–154Unhealthy for Sensitive155–254Unhealthy255–354Very Unhealthy355–424Hazardous425+ | May cause irritation of nose, throat, and eyes; can worsen existing respiratory issues. |
Ozone (O₃)(O₃)Ground-level ozone forms when sunlight reacts with emissions. It is different from the protective ozone layer higher in the atmosphere. | ppb | Good0–54Moderate55–70Unhealthy for Sensitive71–85Unhealthy86–105Very Unhealthy106–200 | Can cause chest tightness, cough, and difficulty breathing, especially during exercise. |
Nitrogen Dioxide (NO₂)(NO₂)Gas produced mainly by traffic and combustion sources. It is a marker of urban air pollution. | ppb | Low0–50Elevated50–100High100–200Very High200+ | Irritation of the airways, especially in people with asthma or other lung diseases. |
Sulfur Dioxide (SO₂)(SO₂)Gas released from burning sulfur-containing fuels such as coal and heavy oil, and from some industrial facilities. | ppb | Low0–35Elevated36–75High76–185Very High185+ | Can cause bronchospasm, chest tightness, and shortness of breath shortly after exposure. |
Carbon Monoxide (CO)(CO)Colorless, odorless gas from incomplete combustion (engines, heaters, fires). Outdoor levels are usually low, but spikes can matter. | ppm | Typical outdoor0–5Elevated5–9High10–30Very High30+ | At higher levels can cause headache, dizziness, and confusion by reducing oxygen delivery. |
Ammonia (NH₃)(NH₃)Gas often associated with agriculture, fertilizers, and some industrial processes. | ppb | Low0–25Elevated26–50High51–100Very High100+ | Can irritate eyes, nose, and throat at elevated levels. |
Volatile Organic Compounds (VOCs)(VOCs)A large family of gases from fuels, solvents, paints, and other industrial/household products. They help form ozone. | ppb | Low0–200Elevated200–400High400–1000Very High1000+ | May cause eye, nose, and throat irritation and contribute to headaches and fatigue. |
Pollen levels
Pollen levels describe how much plant pollen is in the air. We categorize them as Low, Medium, High, or Very High.
- Low: Many people have no symptoms, even with seasonal allergies.
- Medium: Allergy-prone people may notice sneezing, congestion, or itchy eyes.
- High: Strong symptoms for most people with pollen allergies; outdoor time may feel tiring.
- Very High: Peak allergy days. Limiting exposure, using filters, and following your care plan is recommended.
Fire & smoke
Local fire smoke
Local fire indicators look at active fires and smoke close to your cell.
Upwind fire risk
Upwind fire risk looks at fires and smoke sources that are not yet above you but are aligned with wind patterns that could bring smoke to your area.