Bad air this week in Delaware; heat increasing locally and globally


Monday will be an Air Quality Action Day for the State of Delaware! Warm temperatures, sunny skies, a very long day length and light winds will provide very conducive conditions for the formation of photochemical smog. As a result, ozone levels will reach the Unhealthy for Sensitive Groups (USG) range, also known as Code Orange on Monday. Extended Forecast: A change in air mass is expected to reach Delaware during the afternoon on Tuesday. In addition, there is a chance of showers both early and late in the day. As a result, we expect cleaner conditions with Moderate air quality on Tuesday. Cooler and less humid on Wednesday with Moderate air quality continuing.”

What this actually means:


Code Orange for ozone and Code Yellow for particles.  Green Delaware calls this combination Code Red, because the effects of different pollutants are somewhat cumulative.  The allergy report from for Monday and Tuesday are “Medium.”  Combine this with forecast temperatures near ninety and high humidity, and we get seriously unhealthy conditions.


The forecast is for Code Orange for both ozone and particles, so we call this Code Orange, combined with medium allergens and hot/humid conditions.


Code Yellow for ozone.

Overall:   While Delaware air quality has in many cases improved somewhat, the state continues to have unhealthy are much of the time and really bad air way too often.

More forecasts and maps can be found at

The Bigger Picture

Weather and climate throughout the world continue to change as a result of human-caused emissions of carbon dioxide, methane, and other climate-changing substances.  On June 20, 2016, the Delaware Division of Public Health issued this statement:


“Climate change is causing the average high temperature to increase and for there to be longer and more frequent periods of extreme heat.”

“Extreme heat is especially dangerous for seniors, young children, people with disabilities, and people with breathing conditions and other chronic medical conditions, such as asthma, chronic obstructive pulmonary disease, and other respiratory and cardiovascular problems. Also at risk are people without access to air conditioning, fans, or cooling shelters.”

This document makes no mention of the effects of heat and humidity combined with air pollution, but is still worth reading for guidance on how to cope with heat emergencies.

Extreme heat is becoming more common.  Recently temperatures reached 121 degrees in Palm Springs, CA.

The Weather Channel reports on recent conditions in the Middle East:

“Mind-boggling combinations of heat and humidity continued to emerge in cities near the Persian Gulf Wednesday, sending feels-like temperatures [heat index] toward the 160-degree mark yet again as relentless heat continued to broil much of the region.

Even in the Middle East, where scorching heat is part of everyday life during the summer, coping with extreme temperatures has its limits. A heat wave that has been building for days is testing those limits – and is testing the region’s national temperature records too.

 The searing heat led to an impromptu, mandatory four-day holiday in Iraq beginning last Thursday.”

A report from 2015 notes:

“A new study modelling temperature rise in the Persian Gulf says climate extremes in the region may hit deadly levels by the end of this century if nothing is done to significantly mitigate greenhouse gas emissions. However, if the international society is able to move away from a ‘business as usual’ approach, curbed emissions could stall the onset of such dangerous heats.”

There are only a few days left in the present session of the Delaware General Assembly.  Have you asked YOUR state Senator and Representative what they have done to limit global warming?

Alan Muller

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