The world is heating up, and so is St. Mary’s County.
Over a century of historical data show temperatures rising, and researchers predict a future with higher rates of extreme heat and precipitation, more warm nights and fewer days that dip below freezing.
Annual average temperatures in the county have risen, according to 130 years of federal data. The annual average temperature for 2000-2024 is 57.9 degrees Fahrenheit. That’s 1.9 degrees warmer than the 20th century mean of 56 F.
The county’s warmest year was 2023. It had an average temperature of 59.7 F.
Scientists predict a range of future impacts in St. Mary’s County if the planet continues to warm.
An interactive map published by the U.S. Global Change Research Program and its partners — but later removed from the web by the Trump administration — used climate models to predict county-level changes at different degrees of global warming.
The Local News Network at the University of Maryland’s Philip Merrill College of Journalism archived that data before it was deleted.
The data shows that with 2.7 F global warming, St. Mary’s County is predicted to experience:
- 31 more days per year with extreme precipitation
- Five more days per year with temperatures over 95 F
- 15 more nights per year with temperatures over 70 F
- 14 fewer days per year with temperatures under 32 F
With 3.6 F global warming, St. Mary’s County is predicted to experience:
- 36 more days per year with extreme precipitation
- 10 more days per year with temperatures over 95 F
- 26 more nights per year with temperatures over 70 F
- 22 fewer days per year with temperatures under 32 F
With 5.4 F global warming, St. Mary’s County is predicted to experience:
- 41 more days per year with extreme precipitation
- 26 more days per year with temperatures over 95 F
- 49 more nights per year with temperatures over 70 F
- 34 fewer days per year with temperatures under 32 F
With 7.2 F global warming, St. Mary’s County is predicted to experience:
- 55 more days per year with extreme precipitation
- 39 more days per year with temperatures over 95 F
- 64 more nights per year with temperatures over 70 F
- 43 fewer days per year with temperatures under 32 F
Note: Data rounded to the nearest whole number.
Changes are compared to data from 1991-2020: for example, 12 more days per year over 95 F means 12 more days compared to the 1991-2020 average.
The federal climate atlas measures global warming by comparing Earth’s average temperatures to those measured from 1851-1900, called the “pre-industrial average.” The Earth is 2 F warmer than the pre-industrial average, according to NOAA.
Climate models used by the National Climate Assessment predict increases in average temperature and precipitation. The U.S. Climate Resilience Toolkit (published by the U.S. Global Change Research Center and NOAA) also predicts more rain, though it notes that “global climate models are simply not as skillful at projecting outcomes for precipitation as they are for temperature.”
