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Maleficent_Rope_7844 t1_j8f1fdd wrote

What is your calculation/ what are your units? Is your chart suggesting that it's been colder the last year during those months than the 4 years prior?

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Legitimate_Proof t1_j8f383b wrote

Hi, the numbers are heating degree days from degreedays.net. Heating degree days are the number of degrees below the base temp, 65F in this case, times the length of time. They are meant to indicate how much heating is needed over a season or other time period. In a non-sense example, if it were 55F for 24 hours straight, that would be 10 heating degree days. My rows are monthly sums of those heating degree days. Since this year has fewer heating degree days, it shows that it's warmer than the past five years.

The National Weather Service also publishes heating degree days as part of their 30-year "climate normals." That's what weather people mean when they say it's warmer, cooler, rainier, windier, or whatever "than normal." They are comparing to the average for the past 3 complete decades. When they did the last update in 2021, they pointed out the many ways it showed warming: https://www.climate.gov/news-features/understanding-climate/climate-change-and-1991-2020-us-climate-normals

https://preview.redd.it/j0mc0004a2ia1.png?width=620&format=png&auto=webp&v=enabled&s=8011013d3609bc6c8237fb6e5c168867867fe965

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