Climate Shift Index Alerts

Using the Climate Shift Index, Climate Central issues alerts when there’s a notable heat event around the world that was made more likely by human-caused climate change. We also produce retrospective analyses to track the local influence of climate change.

Past Climate Shift Index alerts

• September 05, 2023: United Kingdom

• August 23, 2023: Europe

• August 10, 2023: Florida and Puerto Rico

• July 14, 2023: Southwestern U.S.

• July 14, 2023: Europe

• July 11, 2023: Spain

• June 29, 2023: Western U.S.

• June 15, 2023: Southwest

• May 11, 2023: Pacific Northwest

Retrospective analyses

• The hottest 12-month stretch in recorded history (November 2022-October 2023)

• Hot summer days linked to climate change in U.S. cities (U.S. summer 2023)

• Carbon pollution boosted heat for billions during Earth’s hottest summer (northern hemisphere summer 2023)

• Worldwide daily fingerprints of climate change during Earth’s hottest month (July 2023)

About the Climate Shift Index

Climate Central’s Climate Shift Index, grounded in the latest peer-reviewed science, maps the influence of climate change on temperatures across the globe, every day. 

Climate Shift Index levels indicate how much human-caused climate change has altered the frequency of daily temperatures at a particular location. Level 1 indicates that climate change is detectable in that day’s temperature. Level 2 means that climate change made exceptionally warm temperatures in a given location at least twice as likely. Level 5 is the maximum and indicates temperatures at least 5 times more likely because of climate change.

For these analyses, forecast temperatures come from NOAA’s Global Forecast System model, and past actual temperatures come from the ERA5 dataset.