Press Releases
06/04/2025
DEEP Forecasts Elevated Levels of Ozone for June 4–5 2025
Levels May Be Unhealthy for Sensitive Groups During This Time
(HARTFORD) — The Connecticut Department of Energy and Environmental Protection (DEEP) is expecting temperatures to reach the mid-to-upper 80s (˚F) beginning June 4th, with high temperatures persisting and reaching near 90 on June 5th. These warm temperatures will contribute to elevated ozone levels for western Connecticut and inland areas on Wednesday and continuing from southwest Connecticut to northeast Connecticut on Thursday. These levels may approach or exceed Unhealthy for Sensitive Groups (USG) levels for these parts of Connecticut.
Map of Air Quality Forecast for Wednesday, June 4, 2025
Map of Air Quality Forecast for Thursday, June 5, 2025
Connecticut suffers from some of the worst air quality in the United States. In 2024, air quality in Connecticut exceeded the federal health-based standards for ozone (smog) on 23 days, putting vulnerable populations (children, seniors, people with respiratory illnesses, and adults who are active outdoors) at risk. Air pollution is linked to respiratory conditions such as asthma and can be a major driver of health care costs: according to the Connecticut Department of Public Health, in 2023, Connecticut incurred nearly $120 million in acute care charges due to asthma as a primary diagnosis.
“With the expected high temperatures and smoke from the Canadian fires above Connecticut, we’re expecting unhealthy levels of ozone as air pollution from the mid-Atlantic combines with home-grown air pollution from transportation sources including higher emitting cars and trucks operating on Connecticut’s roads,” said DEEP Commissioner Katie Dykes. “As hot temperatures and hazy skies persist, unhealthy levels of ozone production will likely extend into Thursday.”
“Vulnerable populations, including children, the elderly, and those with respiratory diseases should continue to exercise caution over the next few days and check AirNow regularly. Even healthy adults who spend prolonged periods outdoors working or exercising should minimize strenuous activities and recognize that poor air quality combined with high temperatures can affect even healthy individuals,” continued Commissioner Dykes.
“Worsening air quality can pose a significant public health risk especially in sensitive groups when paired with warmer temperatures,” said Connecticut Department of Public Health Commissioner Dr. Manisha Juthani, MD. "Children, seniors, and people with pre-existing respiratory or cardiovascular conditions should limit prolonged time outdoors over the next few days. Residents should stay informed with town alerts and updates from their local health departments.”
Health Effects of Air Pollution
When air quality is forecasted to be USG, there is an increased likelihood that individuals in sensitive groups will develop respiratory symptoms and may experience shortness of breath or difficulty breathing. Children and people with asthma or other lung disease are most at risk for experiencing these symptoms. Active children and adults, and people with impaired lung function or cardiovascular disease should limit prolonged outdoor exertion. Peak ozone levels generally occur between 2-8 p.m. EDT, so make sure you get your activity or exercise in before or after these times to minimize adverse health effects.
Weather Summary
Weather models predict that sunny skies will become hazy on Tuesday afternoon due to a smoke plume aloft from Canadian wildfires and remain hazy on Wednesday, contributing to ozone production across the state. High pressure will slowly move offshore on Wednesday as a cold front slowly approaches from the Midwest, allowing for warm temperatures reaching into the mid-to-upper 80s and southwest winds in the morning turning south in the afternoon. On Thursday, high pressure continues to move offshore as the cold front approaches Connecticut. Temperatures will rise to near 90 degrees with continued southwest winds and hazy skies. Overnight Thursday and into Friday, a cold front will slide across Connecticut bringing a slight chance for showers and thunderstorms.
What You Can Do to Help
While ozone levels in the northeast have improved significantly over the last 30 years, Connecticut continues to struggle to meet both the 2008 and the 2015 federal health-based standards for ozone, which are necessary to protect families and children from unhealthy air pollution.
Connecticut has made great strides implementing control strategies to reduce air pollution and establish several new programs and initiatives concerning electric vehicle use and reduction of transportation-related greenhouse gas emissions. To meet the federal health-based standard for ozone, which Connecticut exceeded on 23 days last year, DEEP continues to pursue tools and strategies to further reduce air pollution in Connecticut from sources like cars and trucks while working with EPA to ensure that air transported into Connecticut meets the ozone standard as well.
Additionally, there are steps that we can all take to reduce our contribution to local air pollution. DEEP recommends simple, common-sense steps to reduce air pollution that may even help save you some money at the same time!
- Drive Less – consider carpooling, vanpooling, using public transit or even telecommuting;
- Drive Clean – consider purchasing or leasing an electric vehicle. Learn more by visiting: www.driveelectricus.com and CHEAPR - Home (ct.gov);
- Reduce or Shift Energy Demand – purchase energy efficient products like ENERGY STAR® LED lights and ENERGY STAR® air conditioning, use programmable thermostats set to 78o or higher when no one is home, and use energy intensive appliances like washing machines, dryers and dishwashers later in the day;
- Be Aware of Your Air – Understand the Air Quality Index and sign up to receive alerts so you will know when air quality is predicted to be unhealthy; and
- Small changes add up – When you know there will be an unhealthy air day, make small changes to your routine:
- Refuel your vehicle after dusk and stop refueling when the nozzle clicks off,
- Avoid idling your vehicle unnecessarily and keep tire pressures at their recommended level,
- Delay mowing your lawn or using other lawn and garden equipment,
- Limit your outdoor activity in the heat of the day,
- Refrain from recreational wood burning;
- Remember that knowledge is power! Ask your local school if they participate in the School Flag Program, EPA’s Air Quality awareness tool that uses colored flags based on the AQI to notify teachers, students, administrators and the local community of air quality conditions.
Stay connected and access the daily AQI forecast and real-time air quality data
- Follow us on Twitter
- Sign up to get Air-Quality alerts through Enviroflash
- Visit DEEP’s AQI webpage or call 800-249-1234
- Go to EPA’s AIRNow web page
- Download EPA’s AIRnow app for your phone
Ozone Monitoring Season
DEEP monitors, tracks and forecasts daily air quality levels across Connecticut for ozone from May 1st through September 30th each year and for fine particulate matter (PM2.5) each day of the year. On April 30, 2024, DEEP began informing Connecticut’s regulated community and the general public of the ozone season via the State of Connecticut E-mail list serve and posting air quality forecasts on the DEEP web page, available here.
DEEP encourages daycare providers, summer camps and elder/senior centers to subscribe to the Air Quality Index (AQI). Subscribing to the AQI is fast and easy and will provide you with important information each day about Connecticut’s air quality through the spring and summer. The AQI link provides facts and information regarding ground-level ozone, its’ health effects, what to do on high ozone days, and most importantly what you can do to help reduce ground level ozone in your backyard.- Twitter: @CTDEEPNews
- Facebook: DEEP on Facebook
Contact
DEEP Communications
DEEP.communications@ct.gov
860-424-3110