Extreme Weather and Climate Change
Over the last 50 years, much of the U.S. has seen increases in prolonged periods of excessively high temperatures and an associated expansion of drought. This contributes to larger wildfires burning more acreage per incident, heavier downpours leading to torrential flooding, more intense winter weather events, stronger tropical storms, and a persistent increase in sea level rise across all coasts as baseline temperatures continue to rise.
These shifts from severe weather to more damaging events nation-wide has led to impacts across all 16 critical infrastructure sectors and a growing need to improve resiliency. Extreme weather events have become far more disruptive and destructive than ever recorded and are projected to steadily worsen as global warming progresses.
It is CISA’s mission to ensure critical infrastructure is protected against extreme weather threats and events. Infrastructure built in the 1900s to early 2000s using climate data from the mid-1900s lacks the ability to withstand the changes occurring in both intensity and frequency of extreme weather events and could experience excessive damage or destruction.
CISA analyzes extreme weather and its impacts to critical infrastructure. We discuss potential increases in weather damages with infrastructure owners and operators, conduct exercises centered around damages from major weather events with stakeholders, and develop resiliency focus documents to outline practical guidelines and strategies for implementation.
CISA analyzes and shares current data trends and findings through:
- Weekly summaries on the national-international climate
- Presentations about national, regional, state, or infrastructure-related climate shift and the cascading impacts to physical infrastructure, site operations, and community resilience
- Impact analyses of National Critical Functions
- Factsheets to address mitigation options for consideration against climate extremes
Severe Weather vs. Extreme Weather
Severe weather is considered to be an intense variation of a regionally common weather event, such as a heavy rainfall event or damaging winds. Extreme weather identifies the trend of more severe weather events both in frequency and intensity, such as torrential rain (excessive rain periods where over one month of rain can fall during a single storm) or record breaking peak gusts with widespread wind damage.
Extreme weather is the most intense climate element observed during a given period, typically longer lasting or more damaging than the historical ‘worst case’ events. Infrastructure is built to climatological norms for the 20-40 years prior to development, accounting for typical severe weather events experienced regionally but not planning for withstanding extreme weather events. As climate change continues to amplify extreme weather events, critical infrastructure sites will need to revisit building codes, material limitations, and regional damages during past severe events to address areas at greatest immediate risk.
Extreme Weather Threats
Extreme weather threats are occurrences of unusually severe weather of climate conditions that can cause devastating impacts on communities and agricultural and natural ecosystems. Climate change fuels extreme weather threats.
Droughts have become more frequent, longer, and more severe, causing billions of dollars in damages in the U.S. Droughts can impact critical infrastructure sectors such as transportation, energy and water that millions of Americans depend upon.
The ten warmest years in the 143-year record have all occurred since 2010, with the last nine years (2014–2022) ranking as the nine warmest years on record. Heat events can damage transportation, lead to power outages, and threaten public health.
Over the past 40 years, the average number of acres of forested land consumed by wildfire each year in the United States has increased by 1,000%. Wildfires can disrupt transportation, communications, power and gas services, and water supply.
CISA in Action
Discover how CISA is working to protect our national critical infrastructure from extreme weather and climate-related events.
CISA Applauds the Beginning of Infrastructure Security Month Declaring Infrastructure Security is National Security
In the Eye of the storm
Extreme Weather Resources and PublicationsView All Extreme Weather and Climate Change Resources
Infrastructure Resilience Planning Framework (IRPF)
Resilient Power Best Practices for Critical Facilities and Sites
Exercise Planning Services
Assist Visits and the Infrastructure Survey Tool Fact Sheet
CISA Tabletop Exercise Packages
To request a service or ask a question about Extreme Weather and Climate Change, please send an email to Central@CISA.gov.