The “new normal” is warmer: NOAA releases updated 30-year climate averages
The average temperature has increased across all of the Brazos Valley and rainfall events are becoming more intense
BRYAN, Texas (KBTX) - Every 10 years, NOAA releases an analysis of U.S. weather over the past three decades. From this analysis, values for the average temperature, rainfall, and other factors are calculated. That is then used to understand how daily weather or the climate over a month, several months, a year, or several years compares to what is considered “normal.”
That 10-year update was released Tuesday morning.
According to NOAA: “Known as the U.S. Climate Normals, these 30-year averages — now spanning 1991-2020 — represent the new “normals” of our changing climate. They are calculated using climate observations collected at local weather stations across the country and are corrected for bad or missing values and any changes to the weather station over time before becoming part of the climate record.”
Simply put: “normals” or “averages” are the basis for judging how daily, monthly, and annual climate conditions compare to today’s climate standard.
In the table below, the differences between the old and new normals are calculated by the National Centers for Environmental Information (NCEI). These values show the increase or decrease from the old normals (1981 - 2010) to these new normals (1991 - 2020). Some interesting notes:
- The yearly, average temperature for Bryan-College Station increased by 0.4°
- The monthly average high temperature increased for each of the 12 months of the year
- The monthly average low temperature decreased in May, October, and November. This is particularly interesting for the later two months as bigger cold snaps are arriving in Texas than compared to the prior 30-year average
- June and July have now even drier than ever before
- The overall, yearly rainfall average has increased by 1.69″. However, the number of days with measurable rain has remained steady or decreased. This increase is a result of more days with heavy rain (equal to or greater than 1.00″). According to the National Weather Service, “this suggests both an increased risk of drought and an increased risk for flash flood events.”
For the entire nation, the yearly normal temperature is now 53.3° (11.8°C) based on weather station data from 1991 to 2020, nearly half a degree warmer than a decade ago. Twenty years ago, normal was 52.3° (11.3°C) based on data from 1971 to 2000. The average U.S. temperature for the 20th century was 52° (11.1°C).
The new normal annual U.S. temperature is 1.7 degrees (0.9 Celsius) hotter than the first normal calculated for 1901 to 1930.
Mike Palecki with the NCEI notes, “this shift [to warmer normals] will result in there being fewer ‘above normal’ temperature days in most of the U.S. at the start of this decade, compared to recent years that used the previous [cooler] normals cycle.”
It is noted that the pace of this warming climate changes from decade to decade to decade due to other climate influences, both natural and man-made. Some examples include the Dust Bowl and smokestack pollution before the Clean Air Act was put into place in 1963. A pattern of cooling was noted in the 1941-1970 normals and continued to do so over the next two periods. However, since then, the cooling pattern began weakening with the 1971-2000 normals. It has all but disappeared today. That is a pattern that can be seen when looking back all the way back to 1901 at what has been considered “normal” in Bryan-College Station.
Below is a breakdown of the new 1991-2020 normals compared to the now outdated 1981-2010 normals:
The new normals for additional locations and a complete look at daily and seasonal normals can be found HERE.
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