You often hear meteorologists refer to a temperature as above or below normal. But what is considered normal? That gets revised every 10 years…and May 5th is the first full day with the new revision.
Here’s further explanation… this average high and low (graphic below) is derived from taking thirty years worth of data. This number is generated by taking 30 years worth of actual highs and lows and getting the average for a specific day. The average high for May 5th is 64 degrees. It puts into perspective the forecast high, which you can see is a little below normal.
Before yesterday, the data used to make the averages were taken from the 30-year span of 1981 to 2010… Now, we shift it to include a new decade. The 80s were dropped… so now we have the average high taken from data between 1991 to 2020. This is important because as our earth warms and cools in various locations, this takes into account how our averages are changing.
Here’s an overall view of the temperatures with the new set of data… we’ve actually cooled slightly here in the Dakotas but the rest of the country warmed significantly.
Here’s how this breaks down monthly (graphic below). You can see we technically trended cooler than normal but by less than a degree overall. The changes weren’t drastic for us in this part of the country.
Here are the national changes for precip (graphic below)… what you’ll find interesting with our ongoing drought… is that over the last 30 years, we have been slightly above normal in precip.
Broken down monthly, you’ll see that we have started to see drier winters and wetter summers.
You may be asking why is this important? Not only does it put your daily weather into perspective but it also impacts planning in the public and private sectors. Future building design and construction are affected… we also have to plan on our energy consumption with our power sources. We’ll wanna watch our trends for farmers and ranchers because if we do start to trend cooler in this part of the country, that could mean a change in the frost and freeze dates. These are just a few reasons why this is important.
For more Weather Whys topics: https://www.kxnet.com/weather/weather-whys/