Extreme Heat risk in Delaware

Extreme Heat in Delaware: What You Need to Know

Delaware experiences hot, humid summers typical of the Mid-Atlantic region. The state’s overall risk from extreme heat is rated as moderate (Level 3 of 5) in the National Risk Index, meaning heat events are likely enough and could cause isolated impacts. While Delaware is small, its climate varies: coastal areas near the Atlantic Ocean and Delaware Bay are often moderated by sea breezes, while inland and urban areas tend to be hotter. Wilmington and other cities face the urban heat island effect, where paved surfaces and buildings trap heat, making nights warmer too.

The hottest weather usually arrives between June and August, but extreme heat events can occur in May or September as well. Heat waves in Delaware are often accompanied by high humidity, which reduces the body’s ability to cool itself. The combination of heat and humidity is measured by the National Weather Service using the heat index. When the heat index reaches high levels, the NWS issues heat advisories or excessive heat warnings.

According to the Delaware Emergency Management Agency (DEMA), extreme heat is a recurring hazard for the state. Prolonged periods of high temperatures can strain infrastructure, increase energy demand, and pose health risks, especially for vulnerable populations.

How Extreme Heat Affects Homes in Delaware

Extreme heat can affect your home in several ways. Building materials expand and contract as temperatures swing between hot days and cooler nights. Over time, this can cause roofing materials to crack or warp, siding to buckle, and foundation walls to shift. The sun’s ultraviolet rays can also degrade sealing and caulking, creating gaps where water can enter.

In Delaware’s humid climate, heat and moisture together create ideal conditions for mold and mildew. This is especially true in attics, crawl spaces, and bathrooms where ventilation is inadequate. If your home loses power during a heat wave, air conditioning stops, and indoor temperatures can quickly rise, putting stored perishables at risk and making living conditions uncomfortable.

When it comes to insurance, it is important to know that damage caused by gradual wear and tear, such as cracking from expansion and contraction, is typically not covered by standard homeowners insurance. However, related damage from events that are covered, such as a fire caused by an overheated electrical system, may be covered. Review your policy and talk to your insurance provider to understand exactly what is included.

How to Prepare Your Home

• Seal gaps and cracks: Use weather stripping or caulk around windows, doors, and roof penetrations to keep hot air out and cool air in.
• Add or upgrade insulation: Proper attic insulation helps block radiant heat from entering your living space. An insulated attic can reduce the load on your cooling system.
• Ensure attic ventilation: Ridge vents or roof vents allow hot air to escape, preventing heat buildup in the highest part of your home.
• Maintain your cooling system: Have your air conditioner serviced before summer. Replace filters regularly and make sure the unit is sized correctly for your home.
• Use ceiling and attic fans: Fans can circulate air and make you feel cooler, allowing you to raise the thermostat a few degrees.
• Install reflective window coverings: Shades, blinds, or low-emissivity (low-E) film can block solar heat gain on south- and west-facing windows.
• Plant shade trees: Deciduous trees on the southwest side of your home provide natural shade in summer while letting sunlight through in winter.
• Create a cool shelter: Designate one room with good airflow or a window unit that can be closed off, so you have a safe place to stay during peak heat.
• Use a programmable thermostat: Automatically raise the temperature when you are away and cool the home before you return, saving energy while protecting the house.
• Consider backup power: Portable generators can keep fans and a refrigerator running during a heat-related power outage. Never run a generator indoors. Follow the manufacturer’s safety instructions.

Frequently Asked Questions

Does homeowners insurance cover damage from extreme heat?

Standard homeowners insurance typically does not cover gradual damage caused by heat, such as warping or cracking from normal expansion and contraction. It may cover sudden, accidental damage if it is linked to a covered peril, such as a fire from electrical overheating. Check with your insurance agent to understand your policy’s specific terms.

What qualifies as extreme heat in Delaware?

Extreme heat is a period when temperatures are much hotter than the regional average and may put people at risk for heat-related illness. The National Weather Service uses the heat index, which combines temperature and humidity, to decide when to issue advisories and warnings. Pay attention to local forecasts and NWS alerts for guidance.

Should I install a generator to prepare for heat-related power outages?

Having a portable generator can help you run fans, a refrigerator, and other essential equipment during a heat-related outage. However, generators must never be used indoors or in enclosed spaces because they produce carbon monoxide. Install a carbon monoxide detector and follow all safety guidance from the manufacturer and from the National Weather Service.

Official Resources

• Delaware Emergency Management Agency
• NWS Heat Safety
• Ready.gov – Extreme Heat
• CDC – Extreme Heat