Sacramento’s 100+ degree days could triple in next 30 years, new climate tool shows
If the effects of climate change continue unchecked, Sacramento could exceed 90 degrees for about one-third of the calendar year beginning in 2035, and reach triple digits nearly 50 days a year by the middle of the century.
That’s according to a new online tool created released Monday by Public Health Institute’s Public Health Alliance of Southern California in partnership with the UCLA Luskin Center for Innovation.
The tool — available at heat.healthyplacesindex.org — displays expected increases in extreme heat impacts across California cities, counties, ZIP codes and other geographic boundaries such as congressional districts.
Extreme heat indicators for those locations include projections of days above 100 degrees and above 90 degrees, for the periods of 2035 to 2064 and 2070 to 2099.
The map shows Sacramento County is projected to average 49 days above 100 degrees and 122 days above 90 degrees for the period from 2035 to 2064. The numbers are similar for the city of Sacramento, at 46 days and 120 days, respectively.
Between 1981 and 2010, downtown Sacramento averaged 74 days a year of at least 90 degrees and only 16 in triple digits, according to the National Oceanic and Atmospheric Administration’s climate normals for that 30-year period. NOAA’s climate data for 1991 to 2020 did not include breakdowns of average days above 90 and 100.
That means the Public Health Institute map tool predicts about a 62% increase in days reaching at least 90 degrees and a near-tripling of triple-digit days from 2010 to 2065.
The tool, called the California Healthy Places Index: Extreme Heat Edition, also includes demographic and resource information detailing cities’ and neighborhoods’ vulnerabilities to extreme heat.
“Open and accessible data on extreme heat impacts, linked with opportunities and funding sources, is key to empowering communities to build healthy, resilient neighborhoods,” Tracy Delaney, founding executive director for the institute’s Public Health Alliance of Southern California, said in a prepared statement.
The institute says the tool can be used by government agencies, community organizations and members of the public.
“We are glad to have more data to work with when developing policy recommendations around extreme heat conditions and how it effects the city of Sacramento, especially those residents most vulnerable to the impacts of extreme heat,” Matt Hertel, the city’s long-range planning manager, said in an emailed response.
“We will be reviewing the data internally to see how we can use this information going forward.”
The map can also sort extreme heat data by school district, for use by administrators and other education officials.
“Communities with healthier conditions (higher HPI score) such as tree canopy, healthy housing, economic security and transportation are better positioned to prepare, respond and recover from extreme heat events,” the institute said in a Monday news release announcing the tool. “Place does matter and a resilient community is a healthy community.”
As for the deeper future, the modeling shows Sacramento County reaching 146 days a year of 90-plus and 73 days of 100-plus weather by the period beginning in 2070.
The forecasting uses data from California’s “four priority global climate models,” according to the tool’s webpage. It assumes a scenario known as Representative Concentration Pathway 8.5, which is sometimes nicknamed the “business-as-usual” model for greenhouse gas emissions and concentrations.
The increases are extreme in some parts of the capital region, especially within the Sierra Nevada foothills.
Auburn averaged only six days per year of 100 degrees or hotter from 1981 to 2010, NOAA data show — but the Public Health Institute data map shows the city could average 49 such days from 2035 to 2064. That would be a more than eight-fold increase.
Placerville could more than quadruple from 11 days of triple-digits per year to 47 by mid-century, according to the map.
This story was originally published July 11, 2022 at 1:44 PM.
