Dr. Smog is an air quality monitoring tool, not a medical service

Dr. Smog is a real-time air quality information system run by the South Coast Air Quality Management District (SCAQMD), which covers Los Angeles County, Orange County, Riverside County, and San Bernardino County in Southern California. It displays current pollution levels at monitoring stations across the region and forecasts air quality for the next few days. The tool is free and open to anyone — you do not need to register or provide personal information to use it.

Despite its name, Dr. Smog does not provide medical information or treatment. It is a public information resource designed to help residents understand when air pollution is high enough to affect their health, so they can decide whether to limit outdoor activity or take protective steps. The system measures five main pollutants: ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter (PM2.5 and PM10).

Key Takeaways

  • Dr. Smog shows real-time air quality readings from monitoring stations across four Southern California counties and provides forecasts for the next few days.
  • The system uses a color-coded scale (green, yellow, orange, red, purple) to show whether air quality is good, moderate, unhealthy for sensitive groups, unhealthy, or very unhealthy.
  • You can check conditions for your specific location by entering your zip code or selecting a monitoring station on the map.
  • Air quality forecasts help you plan outdoor activities in advance, especially if you have asthma, heart disease, or other conditions affected by pollution.

How to access Dr. Smog and check your local air quality

Dr. Smog is available online through the SCAQMD website at www.aqmd.gov. You can also find it through the SCAQMD mobile app, which sends notifications when air quality reaches unhealthy levels in your area. The tool works on any device with a web browser — no read or account is required.

To check air quality for your location, enter your zip code into the search box on the main page. Dr. Smog will display the nearest monitoring station and show you current conditions plus a forecast for today and the next few days. If you want to check a different area — for example, where you work or where a family member lives — you can search multiple zip codes in the same session.

The map view shows all active monitoring stations in the region. Clicking on any station displays its current readings and recent history. This is useful if you live near a station boundary and want to see conditions at multiple nearby locations.

Understanding the color-coded air quality scale

Dr. Smog uses a five-color system to communicate air quality at a glance. Green means air quality is good and outdoor activity is safe for everyone. Yellow means air quality is moderate; most people can be outside, but people with respiratory or heart conditions should limit strenuous outdoor activity. Orange means air quality is unhealthy for sensitive groups — children, older adults, and people with asthma or heart disease should avoid prolonged outdoor exertion.

Red means air quality is unhealthy for the general population; everyone should limit outdoor activity, and sensitive groups should stay indoors. Purple

Each color corresponds to a specific range on the Air Quality Index (AQI), a standardized scale used across the United States. The AQI number itself appears alongside the color, so you can see the exact measurement if you want more detail. The color applies to the overall air quality at that location — if one pollutant is high but others are low, the color reflects the worst reading.

What the forecast tells you and how far ahead it looks

Dr. Smog provides air quality forecasts for today, tomorrow, and the day after. The forecast is based on weather patterns, historical pollution data, and current emissions levels. Forecasts are typically more accurate for the next 24 hours and become less precise further out, just like weather forecasts.

The forecast helps you plan outdoor activities in advance. If you see that air quality will be orange or red tomorrow, you can schedule indoor activities instead, or plan outdoor time for early morning when pollution levels are often lower. Parents can use the forecast to decide whether to let children play outside after school. People with respiratory conditions can prepare by having medication on hand or adjusting their schedule.

Forecasts update daily, usually in the morning. If conditions change unexpectedly — for example, if a wildfire moves into the region — the forecast may be updated during the day. Checking Dr. Smog the morning of your planned activity gives you the most current information.

Why air quality varies by location and time of day

Air quality is not uniform across the four-county region. Pollution concentrations depend on where emissions come from (traffic, industry, wildfires), wind patterns that push pollution around, and geography that can trap pollution in valleys. A location 20 miles away may have significantly different air quality than your neighborhood.

Air quality also changes throughout the day. Ozone, the main pollutant in Southern California, typically peaks in the afternoon and early evening as the sun heats the atmosphere. Carbon monoxide and nitrogen dioxide are often highest during morning and evening rush hours when traffic is heaviest. Particulate matter can spike at any time, depending on dust, smoke, or industrial activity.

This is why checking Dr. Smog for your specific zip code matters more than checking a regional average. The monitoring station nearest you gives you the most relevant information for your actual exposure.

Who should pay close attention to Dr. Smog readings

Certain groups are more vulnerable to air pollution and should check Dr. Smog regularly. These include children under 14, adults over 65, people with asthma or other chronic lung disease, people with heart disease or high blood pressure, and people who are pregnant. People taking medications that affect the heart or lungs should also monitor air quality.

If you fall into one of these groups, consider checking Dr. Smog as part of your daily routine — the same way you might check the weather forecast. On days when air quality is forecast to be orange or worse, you can adjust your plans to reduce outdoor exertion. Even if you do not have a diagnosed condition, if you notice that pollution makes you cough, wheeze, or feel short of breath, pay attention to Dr. Smog readings and limit outdoor activity on high-pollution days.

Outdoor workers, delivery drivers, and others who spend hours outside should also monitor Dr. Smog, since they cannot easily avoid pollution exposure. Some employers adjust work schedules or provide protective equipment on high-pollution days.

Steps to take when air quality is unhealthy

When Dr. Smog shows orange, red, or purple conditions, the SCAQMD recommends specific actions. On orange days, sensitive groups should reduce strenuous outdoor activity — this means avoiding intense exercise, but light activity like walking is usually acceptable. On red days, sensitive groups should stay indoors; the general population should limit outdoor exertion. On purple days, everyone should avoid outdoor activity if possible.

Practical steps include keeping windows closed to prevent outdoor air from entering your home, using air conditioning with the recirculate setting rather than bringing in outside air, and wearing an N95 or P100 mask if you must go outside. Masks work best when fitted properly — a loose mask offers little protection. If you have asthma or another respiratory condition, keep your rescue inhaler with you and use it as directed by your doctor.

Postpone outdoor exercise, yard work, and activities like running or cycling to early morning or evening when pollution levels are lower, or move them indoors. If you have a choice, avoid driving during high-pollution days, since vehicle emissions contribute to the problem.

Frequently Asked Questions

Is Dr. Smog the same as the national Air Quality Index?

Dr. Smog uses the same Air Quality Index scale as the rest of the United States, so the numbers and colors are consistent nationwide. However, Dr. Smog is specific to the SCAQMD region and shows monitoring stations only in Southern California. If you need air quality information for another part of the country, you can use AirNow.gov, which covers the entire United States.

Why does my zip code show no data sometimes?

Some zip codes do not have a monitoring station within their boundaries. Dr. Smog will show you the nearest station instead. If that station is far away, conditions there may not reflect your exact location. If you see "no data available," try searching a nearby zip code or using the map view to find the closest station to you.

Can I get alerts sent to my phone when air quality gets bad?

Yes. The SCAQMD mobile app allows you to set notifications for your location. You can choose to be alerted when air quality reaches a certain level — for example, when it turns orange or worse. You can also sign up for email alerts through the SCAQMD website. These notifications help you stay informed without checking Dr. Smog manually every day.

Does Dr. Smog predict when wildfires will affect my area?

Dr. Smog shows current air quality and near-term forecasts, but it does not predict wildfire smoke days in advance the way weather services predict storms. However, when smoke from a known fire is expected to reach the region, the SCAQMD usually issues a special advisory. You can check the SCAQMD website or sign up for email alerts to receive these notices.

What should I do if I have symptoms but Dr. Smog shows good air quality?

Air quality readings reflect pollution at monitoring stations, not necessarily at your exact location. If you are experiencing coughing, wheezing, or shortness of breath, move indoors or to a different area if possible. If symptoms persist or worsen, contact your doctor. Other causes — allergies, infections, or underlying conditions — can produce similar symptoms even when air quality is good.