October 2023

October has come and gone…time to look back at some climate information.

Not surprisingly, the month was warmer than average, with a departure from “normal” of +1.9F. While the month seemed kind of gray and damp, precipitation was actually below average, with just 1.89″ of rainfall recorded at Hyannis. The highest temperature recorded was 78F and the lowest was 40F. The month closed out with an abnormally warm stretch of weather.

Delving a bit deeper into the data… we can see that not only was the month warmer than normal, it was also more humid than average, which fits the long-term trend for the area. You can see using Hyannis data (which in its official capacity as an ASOS site has a short period of record dating to 1998) that over the last 25 years, daytime and nighttime temperatures have been trending upward, and correspondingly, so have dewpoint values:

Another interesting trend in the long-term data is the lowering wind speeds. From an anecdotal perspective, the summer and fall months around the Cape in 2023 have been NOTICEABLY less windy than normal and the data agrees. In fact, when looking at June 1st through October 31st 2023, the average wind speed recorded is the lowest in the dataset.

Below are three charts: the first is average wind speeds from June 1st to October 31st grabbing all of the available wind data for Hyannis, the second is average October wind speeds and the third is a comparison to the Blue Hill Observatory in Milton, MA which has the longest running climate record in North America. Notice a trend?