Your favorite TV weather anchor usually includes the daily normal or statistical average high or low temperature in their presentation. The averages they offer come from what are called 30-year averages and those 30-year averages just got updated.
Just last month, new 30-year averages for both temperature and precipitation were released in the U.S. using the latest decade of climate data from 2011 to 2020. Going back to the 1980s, the latest 30-year averages again got a little warmer and drier for the North Sound, a trend that has continued throughout much of the 20th century.
The previous 30-year averages ran from 1981 to 2010. Every ten years, those 30-year averages get updated using the most recent decade of climate data. So with fresh 2011 to 2020 climate data, the 1980s were dropped and the 2010s were added to create the latest 30-year averages.
Looking at daily average temperatures during the sequence of 30-year averages going back well into the 20th century, North Sound average high and low temperatures have been steadily inching higher. This trend is seen elsewhere in the country as well as around the world. Climatic data give us trends in long-term weather changes.
This topic brings up another question – what is the difference between climate and weather? You might recall these terms taught in your earth sciences class back in school and they are vastly different.
Weather is defined as the state of the atmosphere at a particular place and time. Climate is defined as weather conditions prevailing in an area over a long period of time, generally specified as 30 to 100 years.
Weather is very short term, like today, tomorrow or even a week from now. Climate involves a long period of time in an area, decades or even a century.
Those new 30-year averages offer a fresh set of daily average high and low temperatures, and precipitation, along with annual averages as well. To review, weather involves atmospheric conditions for today or perhaps a week. Climate is very long term, decades or even a century, of prevailing weather conditions in an area.
So when your TV weather anchor shares the average high and low temperature for the day, they are using the new 30-year averages to compare with the expected weather today or later in the week.
For more information about the new 30-year averages, visit NOAA’s National Center of Environment Information. And for climate data in the North Sound, visit the Western Regional Climate Center and their suite of Western U.S. climate data.