This story is the first in a series of blog posts that explore San Diego’s top climate threats and how San Diego Foundation is working with local nonprofit partners to address solutions.

San Diego is known as America’s Finest City for good reason. The weather, beaches, culture and laid-back lifestyle make San Diego a perfect place to visit or call home.

But climate change is presenting real challenges to the region, threatening homes, the landscape and even livability as climate threats from wildfires to sea-level rise continue to grow. The San Diego Foundation Climate Initiative is working with partners throughout the region to present solutions to San Diego’s top five climate threats, including extreme heat.

Extreme heat

Extreme heat is simply defined as when the local weather is much hotter than usual. In San Diego, extreme heat days are reported when the temperature reaches above 93.1 degrees. According to the Equinox Project’s Quality of Life Dashboard, San Diego County’s five warmest years since 1985 have all occurred in the past decade.

Unfortunately, climate change will make extreme heat days hotter and more frequent in the future. Extreme heat not only affects the plant life and ecosystems of San Diego, but it can also cause heat exhaustion, heat stroke or death for vulnerable residents, such as babies and young children, the elderly, people with chronic health conditions and others. As we look towards the future, it’s important to mitigate and adapt to future threats, such as increasing cool zones and trees, providing shade structures, installing cool pavement and implementing green roofs.

According to the city of San Diego’s Climate Resilient SD Plan, the goal of climate change mitigation is to reduce greenhouse gas emissions, slow down global warming and avoid the worst potential impacts of climate change. Conversely, the goal of climate change adaptation is to reduce impacts from the harmful effects related to climate change. Climate adaptation and resiliency strategies can also focus on increasing community resilience, or the ability to bounce back — and bounce back better — after a climate event, like historic flooding or record-breaking heatwaves.

Community Solutions

In September 2019, San Diego Foundation partnered with the City of San Diego, National Oceanic and Atmospheric Administration and Climate Adaptation Planning + Analytics (CAPA) Strategies to better understand how extreme heat impacts the region’s communities. Thanks to the help of dozens of volunteers, thousands of temperature and humidity data points were collected over a two-day period to illustrate where extreme heat is experienced most intensely across the city and what steps we might take to build community resilience to it.

Areas with large concentrations of pavement and concrete, combined with limited tree canopy cover show to be hit the hardest by extreme heat, such as City Heights and Southeast San Diego. These neighborhoods are known as urban heat islands, where according to this heat mapping campaign, temperatures can reach up to 20 degrees hotter than in more coastal communities.

There is much that can be done to protect communities from extreme heat. Strategies such as increasing and maintaining tree coverage, building shade structures and cooling zones, investing in green infrastructure, and installing green or cool roofs to reflect heat exist as opportunities to build community resilience to extreme heat. To learn more about the results of this heat mapping campaign, check out CAPA Strategies’ “San Diego Heat Watch Report.”

About the Climate Initiative

Since 2006, the San Diego Foundation Climate Initiative has provided leadership and philanthropic investment to create a more sustainable path towards economic growth and a higher quality of life for San Diegans. The initiative advances science-based, collaborative development of local policies and programs that reduce our region’s polluting emissions and help us adapt and prepare to minimize local impacts from climate change.

Learn more about the Climate Initiative.