The effects of climate change are already upon us. Much of the globe is experiencing abnormal temperatures and anomalous weather patterns. The Pacific Northwest saw an intense summer heat dome in a part of the world where summers are normally so mild that most people don’t even have air conditioners. 

Small changes in average temperature may not seem to matter much, but they can have drastic effects on water supply and the ability to grow crops, increasing the frequency and severity of droughts, and leading to desertification in many once arable parts of the world. (These are the hottest inhabited places on earth.)

Meanwhile, melting polar ice means rising sea levels, which threatens the many millions of people who live near the coast. (Here are 25 cities where rising seas could leave millions homeless.)

Rising temperatures also precipitate natural disasters of various kinds. Natural disasters have always occurred on the planet, of course, but shifting climate patterns can make them much more frequent and severe. Forest fires are on the rise, for instance, and hurricanes have been more intense.  

This year’s Hurricane Ida, for instance, made landfall in Louisiana and traveled all the way north to New Jersey, causing massive flooding along the way in areas that rarely if ever experience the effects of such storms. Many other places have also struggled as they experience catastrophic weather events for the first time.  

To determine which states recorded the most unusual temperatures this year, 24/7 Wall St. reviewed data from the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information. States were ranked based on the absolute difference between the average temperature in September 2021 and the historical average temperature for September from 1901 to 2000. Supplemental data used to determine the hottest and coldest average September temperatures on record also came from the NCEI, which maintains records dating back to 1895. (Data for Hawaii was not available.)

Click here to see how global warming is affecting every state