Climate at a Glance: U.S. Temperatures

Map of 30 year U.S. Temperature trends. Source: NOAA via climate.gov

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Bullet-Point Summary:

  • There has been no significant warming in the United States since at least 2005.
  • Any claimed recent warming and impacts at specific places in the United States are isolated and indicative of random variation rather than long-term warming.
  • Claims of long-term U.S. warming are controversial. Thermometer readings in the United States report current temperatures are similar to the temperatures recorded 80 years ago.

Short Summary: The United States has experienced no significant warming since at least 2005. The lack of warming is documented by the National Oceanic and Atmospheric Administration’s U.S. Climate Reference Network, an extremely accurate network of temperature stations throughout the United States that requires no corrective adjustments. (It began reporting temperature data in 2005.) When climate activists claim specific impacts of global warming in the United States, those impacts could not have been caused by any recent warming because no significant recent U.S. warming has occurred.

Figure 1: U.S. Temperature Trend Since 2005

Figure 1: (click to enlarge) Data provided by U.S. Climate Reference Network, National Oceanic and Atmospheric Administration, accessed January 2020: https://www.ncdc.noaa.gov/crn. Chart provided by meteorologist Anthony Watts.

Longer-term warming in the United States has been modest, at most. Thermometer readings report current temperatures are no higher than they were 80 years ago. This has been masked in large part by government gatekeepers who have inexplicably adjusted temperatures from past decades downward, making it appear as though recent temperatures have risen more than they have. Raw data show current temperatures are approximately the same as they were in the 1930s.

Figure 2: Long-Term U.S. Temperature Measurements vs. Adjusted Temperature Reports

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Figure 2: (click to enlarge) The blue line represents unadjusted thermometer readings, which show temperatures are no higher now than they were 80 years ago. Source: Tony Heller, “61% Of NOAA USHCN Adjusted Temperature Data Is Now Fake,” realclimatescience.com, February 11, 2019: https://realclimatescience.com/2019/02/61-of-noaa-ushcn-adjusted-temperature-data-is-now-fake

Additional Information: Anthony Watts, “Is the U.S. Surface Temperature Record Reliable?,” March 1, 2009: https://www.heartland.org/publications-resources/publications/is-the-us-surface-temperature-record-reliable


Climate At A Glance is a Project of The Heartland Institute

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