Last week, the National Oceanic and Atmospheric Administration (NOAA) released new climate normals for the US. So, what does this actually mean? A climate normal is a 30-year average of measurements from weather variables like temperature and precipitation from thousands of local weather stations across the entire country. The data get corrected for erroneous or missing values and the process takes many months, involves hundreds of scientists, and undergoes heavy scrutiny. Using 30 years of data ensures that the numbers are not skewed by any short-term swings. The previous average spanned 1981 – 2010. The “new normal” spans 1991 – 2020. In a nutshell, normals are “the basis for judging how daily, monthly and annual climate conditions compare to what’s normal for a specific location in today’s climate.”
Images showing temperature and precipitation normals through time can be found here: https://www.noaa.gov/news/new-us-climate-normals-are-here-what-do-they-tell-us-about-climate-change. Comparing with the 20th century average, what are the trends? The most recent temperature map has the most widespread and darkest reds, revealing the influence of long-term global warming. The country as a whole has warmed 1.7 degrees F since the early 20th century (though some parts have warmed more in the 2 – 4 degree F range, while others haven’t warmed as much). In regards to precipitation, the last few maps in the series (1961 – 1990, 1971 – 2000, 1981 – 2010 and 1991 – 2020) show wetter conditions in the Midwest and Northeast, with drier conditions in the Southwest. The latter result is no surprise, given drought conditions and intense fires in recent years in the west. Why overall wetter? As climate warms, it causes more water to evaporate from the ocean and land and “wet” the atmosphere instead, leading to more rain and snowfall.
This climate update is essential for the agriculture, water and energy conservation, travel and tourism sectors, in order to inform people on what to expect. But one thing is clear: we have to make sure that reporting of this new normal doesn’t normalize our changing climate – it’s getting hotter. The evidence is right here for anyone who still doubts climate change. Question now is, what are we going to do about it, to avoid the worst of consequences? Thankfully, there’s lots in progress! Check this out: https://solarimpulse.com
You can take a closer look at US (national) trends here: https://www.ncdc.noaa.gov/temp-and-precip/us-trends/prcp/ann
Want to check out changes for your home state? Have a look here: