Cape Cod weather is like a temperate marine climate. Although Cape Cod's weather is typically more tame than inland locations, there have been occasions where the Cape has dealt with extreme weather situations (such as the Blizzard of 2005 and Hurricane Bob).
Temperatures are typically a few degrees cooler in the summer and a few degrees warmer in the winter. This is due to the influence of the Atlantic Ocean on Cape Cod weather.
A lot of people mistakenly think the climate is influenced largely by the warm Gulf Stream current, however that current turns eastward off the coast of Virginia and the waters off the Cape are more influenced by the cold Canadian Labrador Current.
Because of this, the ocean temperature rarely gets above 65 °F (18 °C), except along the inside of the Cape where the area is more shallow.
As a matter of fact, we sometimes joke that all the swimmers are probably Canadian. The water is very chilly and I always wear a wetsuit when surfing or boogie boarding. If I go in for a quick dip, I don't wear one and the swim is a short one. It seems the younger you are, the longer you can stay in the water. When I was a kid, I could spend hours in this brisk surf but now....
The Cape's climate is also well known for a delayed spring season. The reason for this is because it is surrounded by an ocean which is still cold from the winter.
Cape Cod weather in the fall is exceptionally mild, thanks to the ocean remaining warm from the summer. This is the best time to go in my opinion due to the warmer water and less expensive lodging rates.
The early mornings are sometimes a little crisp but by 10AM or so, it is very warm. The fall also brings great sleeping weather as the nights are cooler-great for nursing that sunburn!
Here is a chart showing Cape Cod average temperatures
throughout the year:
Cape Cod weather is more temperate than surrounding areas (cooler in summer, warmer in winter) because of the ocean's influence. Sometimes you will need to pack for 2 seasons.
If you go out on the open water in a boat for whale watching or fishing, always bring long pants, a warm top and a light jacket-- even in July and August. Out at sea, Cape Cod weather can be dangerous so be prepared.
Here are a few pointers depending on when you visit the Cape. And remember, "If You Don't Like the Weather On Cape Cod, Wait 5 Minutes."
Pack for snow, rain and a few sunny days in the 40's-50's. This includes a heavy coat, gloves, insulated boots or shoes and sweaters. If you have anything waterproof then bring it.
April is variable with a light snowfall of 2 in early April. Temperatures on Cape Cod are in the 40's-50's. Light jackets, fleece, lighter mitts, sweatshirts and long pants are good to pack. Waterproof gear also recommended.
Cape Cod Weather in May brings hints of summer. Temperatures are in the 50's-60's. Lightweight pants, cotton sweaters, and a medium to light jacket will be fine.
Please remember to throw in a pair of shorts and a T-Shirt. One time we were down on our Canadian May 24th weekend and as we were in Boston traffic, it was 30 Celsius (86 F). We knew we were in trouble because we had packed sweatshirts, jeans, boots--and little else. As soon as we got to the Cape, we hit a surf shop and bought shorts and sandals.
Count on beautiful early summer weather--not too cool, not too hot (60's-mid 70's). Bring lightweight pants, some shorts, shirts, and a sweatshirt. You will need a spring type jacket at night. Bring sunscreen along with your beach gear. The weather is nice enough to sit on the beach all day but the wind coming off the water can be chilly at times.
Awesome Cape Cod beach weather in the 70's-80's, a light breeze with cool nights. Pack for summer, but bring pants and a sweater or sweatshirt. Better yet, buy one at Cuffy's.
Slightly cooler than July August. Beach weather possible most of the month so bring all your summer gear but also a light jacket.
This is where Cape Cod weather starts to really change. You will see temperatures in the 50's-60's during the day with chilly nights in the 30's-40's. Bring warmer pants, turtlenecks, a sweater or two and a medium jacket. I have ventured into the ocean at this time of year but I was surfing and was wearing a full wetsuit.
November on Cape Cod can be like winter so pack winter wear and focus on layering. Snow is uncommon in November, but bring gloves and a hat.
The weather on Cape Cod is definitely cold. You will see snow sometimes in December so bring winter gear. Bank on a Green Christmas.