If you have noticed the air not seeming as fresh in the summer, you are not alone. Heat can really contribute to poor air quality and some parts of the country are more susceptible than others. Additionally, high temperatures can leave us trapped inside most of the day where air quality is up to 5 times worse than outdoors. Even if you have noticed the decrease in air quality, it can be confusing to figure out why the air is so much worse during the warmer months, especially when that is the season we want to spend the most time outside in the sun.
The relationship between temperature and air quality is more complex than many people realize, involving chemical reactions, weather patterns, and seasonal factors that all converge during the hottest months of the year. Understanding these connections can help you better protect yourself and your family from the hidden dangers of summer air pollution.
How Heat Impacts Air Quality
Ozone Formation
Sunlight and high temperatures accelerate the production of ozone in our air. Ozone (the main component of smog) is formed when pollutants like nitrogen oxides and volatile organic compounds that come from vehicles, manufacturing facilities, power plants, and even household products, are exposed to sunlight. Think of it as a massive outdoor chemistry experiment happening right above our heads. Stronger UV indexes and more direct sunlight speeds up this process reducing air quality across the board.
Ground-level ozone concentrations typically peak in the afternoon when temperatures are highest and sunlight is most intense. This is why air quality alerts are most common during hot summer afternoons, particularly in urban areas where there's an abundance of the chemical precursors needed for ozone formation. Cities like Los Angeles, Phoenix, and Houston are particularly vulnerable due to their combination of high temperatures, abundant sunshine, and significant pollution sources.
Ozone can cause respiratory problems and increase asthma symptoms in vulnerable populations, but its effects extend beyond those with pre-existing conditions. Even healthy individuals may experience chest tightness, coughing, and reduced lung function when ozone levels climb. Be sure to keep an eye on ozone levels, especially if you live in an urban area with lots of vehicular traffic or manufacturing facilities.
One thing to keep in mind is that humidity and summer storms can drastically reduce the amount of ozone in the environment. Storm clouds block sunlight which slows down ozone production, and moisture from rain or humidity destroys ozone that has already formed. That fresh air you breathe in after a rainstorm isn't just in your head – the air quality genuinely improves as ozone molecules are broken down by water vapor and washed out of the atmosphere.
Particulate Matter
Particulate matter consists of tiny particles that are small enough to float around in the air we breathe. They are too small to see with the naked eye but can consist of particles like dust, dander, pollen, soot, smoke, and various chemical pollutants. These microscopic particles are measured in micrometers, and for perspective, PM2.5 particles are less than 2.5 micrometers in diameter, which is roughly 30 times smaller than the width of a human hair.
Particulate matter levels often get worse as the temperatures increase for several interconnected reasons. Heat leads to drier conditions which increases risk of wildfires and dust storms which can quickly cause unhealthy levels of particulate matter. The Western United States has seen this connection play out dramatically in recent years, with record-breaking heat waves preceding devastating wildfire seasons that send smoke particles hundreds or even thousands of miles from their source.
Spring and summer are beautiful seasons, but they come along with increased pollen levels from all those blooming grasses, trees, and flowers. While pollen is a natural part of our environment, rising temperatures and increased CO2 levels are actually making pollen seasons longer and more intense than they were decades ago. This means more particulate matter in the air for longer periods of time.
Stagnant Air
Heat waves often occur when air is trapped in a particular area by high-pressure systems that act like invisible domes over regions, preventing air from moving freely. This stagnant air is the perfect breeding ground for poor air quality since the pollution is stuck in one area and more and more pollutants continue to be added each day from cars, factories, and other sources. It's like filling a closed container with smoke. Without ventilation, the concentration just keeps getting worse.
Wind and breezes are a lifesaver in cooling the air down, but they also keep pollutants moving through an area so that they do not build up heavily over time. During heat waves, these natural cleansing mechanisms are often absent, allowing pollution to accumulate to dangerous levels. This is why some of the worst air quality days coincide with the hottest, most stagnant weather conditions.
Health Impacts of Summer Air Quality
When heading out for a fun summer's day, we are already aware of plenty of risks that the heat and sun can bring. From packing sunscreen to prevent sunburn to bringing extra water to avoid overheating, we should always be prepared for the elements. Air quality is no different and deserves the same level of attention and preparation.
For those with preexisting conditions like asthma or COPD, summer air quality can be particularly challenging. You may need to bring along extra medication if you plan on spending significant time outdoors, and it's wise to check air quality forecasts just as you would check the weather forecast. Many weather apps now include air quality information, making it easier than ever to plan your day around both temperature and pollution levels.
Additionally, high heat can put extra strain on your heart and lungs even without poor air quality, so when you combine extreme temperatures with elevated pollution levels, the health risks compound significantly. Be aware of the symptoms of heat exhaustion, heart attack, or stroke, especially for older, vulnerable populations. Warning signs include chest pain, difficulty breathing, dizziness, nausea, and confusion.
Young children, older adults, those with pre-existing conditions, and those who work or exercise in the heat should be aware of the extra strain placed on their body and respiratory system by both the heat itself and the poor air quality that can result from it. Outdoor workers, athletes, and active families need to be particularly vigilant about monitoring conditions and adjusting activities accordingly.
Improve Your Air Quality This Summer
Typically, outdoor air quality is better than indoor air quality, but of course that is dependent on location and time of year. During hot days in urban areas, the level of pollutants outdoors can reach dangerously high levels, sometimes exceeding indoor pollution levels even in homes without proper air filtration. This can also impact your indoor air quality as well since buildings aren't perfectly sealed environments.
Opening windows and doors can invite pollutants and poor air quality into your home, negating the benefits of any indoor air quality improvements you've made. On days where the heat is high or the air quality is poor, be sure to keep windows closed until the air quality improves. This might mean relying more heavily on air conditioning during summer months, but it's a worthwhile trade-off for protecting your family's health. Bonus tip: upgrade your standard AC filter to the PuroAir Mega MERV 13 Filter, which provides one of the highest levels of residential HVAC filtering.
It can also be very helpful to invest in an air purifier, particularly one designed to handle the specific challenges of summer air quality. A high quality air purifier, like the PuroAir 130i, will ensure that no matter what the conditions or weather is like outside, your home will remain a sanctuary for fresh, clean air. Look for purifiers that can effectively remove both particulate matter and gaseous pollutants like ozone precursors. HEPA filters are perfect for that because of the multi-layer design. The outer layer filters out particulate matter while the activated carbon layer absorbs chemicals and VOCs found in the air. You can be confident that your purifier is handling all aspects of summer air with a Puroair.
Even if the AQI outside is on the rise, rest assured your home will stay safe from pollutants, particles and ozone this summer with air purification on your side. The investment in clean indoor air pays dividends not just in comfort, but in better sleep, improved concentration, and reduced risk of respiratory issues during the challenging summer months when outdoor air quality is at its worst.