Climate at a Glance: U.S. Temperatures

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

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Key Takeaways:

  • 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 trend.
  • Thermometer readings in the United States suggest current temperatures are similar to the temperatures recorded 8 decades ago.

Short Summary:

The United States has experienced no significant warming since 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 located throughout the United States. Unlike other temperature
data, Climate Reference Network data does not require corrective adjustments to account for environmental
factors that alter the accuracy of recorded temperatures.

Figure 1 illustrates there has been no significant increase in the number of temperature anomalies since the start of 2006.1,2 Thus, when climate activists have claimed in recent years that warming has caused various U.S. environmental problems, it’s not possible their assessments are accurate, unless it can be shown the U.S. Climate Reference Network data is wrong, and as far as we’re aware, no credible scientific agency has attempted to make that claim.

Figure 1. Contiguous U.S. Average Temperature Anomalies

Figure 1. Average surface temperature anomalies in the United States, January 2005 to February 2022.
Source: U.S. Climate Reference Network, “Average Surface Temperature, January 2005 to
February 2022,” ncdc.noaa.gov, National Climatic Data Center, National Oceanic and Atmospheric
Administration, last accessed March 31, 2022,
https://bit.ly/3JZfqzg

Further, long-term warming in the United States has been modest, at worst. Thermometer readings report current temperatures are no higher today than they were 80 years ago, a reality that has been masked in large part by government agencies that have chosen to adjust temperatures from past decades downward, making it appear as though recent temperatures are comparably much higher than the unadjusted data suggest. (See Figure
2.)

Figure 2. USHN Monthly Measured vs. Adjusted Temperatures

Figure 2: (click to enlarge) U.S. Historical Climatology Network (USHCN) data. 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

Another factor that has distorted temperature data is the poor placement of temperature stations that are not part of the Climate Reference Network. Many stations’ data have been affected by urbanization, resulting in temperature inaccuracies.3, 4

The raw, unadjusted data, shown in Figure 2, clearly illustrates recent temperatures are likely the same or nearly the same as they were in the 1930s, and perhaps even lower.5

References:

  1. U.S. Climate Reference Network, National Oceanic and Atmospheric
    Administration’s (NOAA) National Centers for Environmental Information, accessed
    August 17, 2021, https://www.ncdc.noaa.gov/crn
  2. U.S. Climate Reference Network, “Average Surface Temperature, January 2005 to
    February 2022,” ncdc.noaa.gov, National Climatic Data Center, National Oceanic and
    Atmospheric Administration, last accessed March 31, 2022, https://www.ncdc.noaa.
    gov/temp-and-precip/national-temperature-index/time-series?datasets%5B%5D=uscr
    n&parameter=anom-tavg&time_scale=p12&begyear=2005&endyear=2022&month=12
  3. See Anthony Watts, Is the U.S. Surface Temperature Record Reliable?, The Heartland
    Institute and SurfaceStations.org, 2009, https://www.heartland.org/_template-assets/
    documents/publications/SurfaceStations.pdf
  4. See Anthony Watts et al., “New Study of NOAA’s U.S. Climate Network Shows a Lower
    30-Year Temperature Trend When High Quality Temperature Stations Unperturbed by
    Urbanization Are Considered,” press release, American Geophysical Union, December
    16, 2015, displaying parts of a presentation delivered before the American Geophysical
    Union, https://web.archive.org/web/20160331214630/https://fallmeeting.agu.
    org/2015/press-item/new-study-of-noaas-u-s-climate-network-shows-a-lower-30-
    year-temperature-trend-when-high-quality-temperature-stations-unperturbed-byurbanization-
    are-considered
  5. 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

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