THE HIGH COST OF HOT

Climate Central's analysis of 244 U.S. cities reveals that 93% have seen an increase in cooling degree days and 87% have experienced more warm nights since 1970. The report highlights the role of urban heat islands and the increasing reliance on air conditioning, which costs Americans over $27 billion annually for home cooling as of 2015. While energy efficiency standards may reduce cooling electricity consumption by nearly 20% by 2040, the report warns that fossil-fuel-powered cooling and improper appliance disposal exacerbate climate change.

• Analysis of 244 U.S. cities shows that 93 percent have experienced an increase in cooling degree days (CDDs), with the most significant rises occurring in traditionally hot cities such as McAllen, Texas, Phoenix, and Las Vegas. Some cooler cities, including San Francisco and Portland, Oregon, have seen their CDDs almost double over the analysis period.
• Overnight minimum temperatures are rising faster than daytime temperatures in the United States; since 1900, the warming rate for overnight temperatures has been more than 20 percent higher than the daytime rate. Consequently, 87 percent of analyzed U.S. cities have seen an increase in nights where temperatures remained above a threshold of either 55°F or 65°F since 1970.
• Urban heat islands, caused by surfaces like buildings and streets absorbing heat, can increase overnight city temperatures by as much as 22°F. While vegetation can reduce shaded surface temperatures by 20–45°F compared to unshaded materials, some urban areas are losing tree cover; for instance, Rhode Island and Georgia lost 44 and 40 percent of their urban and community tree cover, respectively, between 2009 and 2014.
• Air conditioning represents 17 percent of residential electricity use, with Americans spending over $27 billion in 2015 to cool their homes. Costs are highest in the South (Texas, Oklahoma, Arkansas, and Louisiana), where annual costs are nearly $450 per home, compared to an average of $250 nationwide. Projections suggest New England summers will be as hot as current Florida summers by 2100.
• While air conditioning provides immediate relief from heat, it can worsen climate change if powered by fossil fuels or disposed of improperly due to potent heat-trapping gases. However, the EIA estimates that mandated energy efficiency standards could lead to a nearly 20 percent decline in cooling electricity consumption by 2040.

APA

Brady, J. (2018). THE HIGH COST OF HOT. Climate Central. http://assets.climatecentral.org/pdfs/June2018_CMN_Heat.pdf

Chicago

Brady, Jennifer. THE HIGH COST OF HOT. Climate Central, 2018. http://assets.climatecentral.org/pdfs/June2018_CMN_Heat.pdf.

Wikipedia

{{cite report |last1=Brady |first1=Jennifer |title=THE HIGH COST OF HOT |publisher=Climate Central |date=11 July 2018 |url=http://assets.climatecentral.org/pdfs/June2018_CMN_Heat.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{brady2018high, author = {Brady, Jennifer}, title = {{THE HIGH COST OF HOT}}, institution = {Climate Central}, year = {2018}, month = jul, url = {http://assets.climatecentral.org/pdfs/June2018_CMN_Heat.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }