What's a Tourism Score? Forecaster predicts the best summer weather on Cape Cod.

Eric Williams, Cape Cod Times
Updated ·4 min read

This is the time of year when I start thinking about how short the summers are on Cape Cod, mainly because spring is always a big rip-off. Everyone else in New England has leaves on their trees, and there I am, yelling at a maple to get going.

Agitated by our clammy climate, I have spent long nights in my weather silo, trying to figure out the best summer weeks to take off from work and harvest the small serving of atmospheric nirvana that we are allotted on the Cape.

But deciphering weather trends is insanely tricky. The data is out there, but it all seems kind of disjointed, especially to a chowderhead like me who has to take his socks off to count to 20. I was about to give up and book a vacation in Poughkeepsie, but then I stumbled across the Weather Spark website.

A hot sunny day at Mayflower Beach in Dennis in mid-July 2009.
A hot sunny day at Mayflower Beach in Dennis in mid-July 2009.

According to Weather Spark, their site "offers detailed reports of the typical weather for 145,449 locations worldwide." That's when I realized that "typical weather," not forecasts or long-term predictions, was exactly what I was looking for. The site is owned by a small Minneapolis-area company that develops and operates web-based tools and desktop software.

They build their typical weather outlook for Cape Cod "based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016." The reports come from the weather station at Provincetown Municipal Airport, using nearby weather stations as a backup.

Sure, it sounds pretty nerdy, but at least you get the feeling they might know what they are talking about. So here we go with deep dive weather nuggets about the best time in the summer to visit the Cape.

A trip to the ice cream truck on a sunny August day at Riley's Beach in Cotuit in 2009.
A trip to the ice cream truck on a sunny August day at Riley's Beach in Cotuit in 2009.

Let's start with the basics for Cape Cod. According to Weather Spark, "The warm season lasts for 3.2 months, from June 9 to September 16, with an average daily high temperature above 70°F. The hottest month of the year in Cape Cod is July, with an average high of 77 degrees and low of 64 degrees."

August is close to July in the temperature department, with an average high of 76 degrees and an average low of 63 degrees. For argument's sake, let's say these are the two best months for a Cape Cod vacation.

So, we now drill down on the distinctions between the two months. According to Weather Spark, July is muggier than August, based on dew point measurements. July is the least windy month of the year on the Cape and August has the highest water temperatures of the year.

An aerial view of Craigville Beach in late August 2005.
An aerial view of Craigville Beach in late August 2005.

Picking the exact best time to visit Cape Cod still seems tricky, but amazingly, Weather Spark issues something called a "Tourism Score," that helps us get closer to an answer.

According to Weather Spark, the Tourism Score "favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Cape Cod for general outdoor tourist activities is from late June to mid September, with a peak score in the last week of August."

Thus we must ask: is the last week of August the ultimate best time for a Cape Cod vacation? I have my doubts. It seems to me that true hot beach weather, arguably the best for vacations, is in short supply during a Cape Cod summer. So I would hedge my bets toward late July. I also feel like a sneaky hurricane is more likely to whack us in August (like Hurricane Bob in 1991) than July.

And there is also that sense of melancholy at the end of August, not measurable by a barometer, that summer is slipping away. Nope, despite the intriguing and excellent work of Weather Spark, I'm sticking with this: the last two weeks of July are the best time for a Cape Cod summer vacation.

Eric Williams, when not solving Curious Cape Cod mysteries, writes about a variety of ways to enjoy the Cape, the weather, wildlife and other subjects. Contact him at ewilliams@capecodonline.com. Follow him on X: @capecast.

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This article originally appeared on Cape Cod Times: The best month to go to Cape Cod, according to weather forecast maps