Cape Cod Temperatures: Averages by Month





The numbers here tell you how hot and cold the weather usually is at Chatham on Cape Cod, Massachusetts during each month of the year.

The average high and low temperatures are listed below monthly and annually for Cape Cod, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 60, 70 or 80 °F each month at Cape Cod, scroll down farther. There are also monthly and yearly counts of days with cold weather.

All the numbers are averages, based on climate data gathered from 1991 to 2020.

Average Cape Cod temperatures
High °F Low °F   High °C Low °C
39 25 January 4 -4
39 25 February 4 -4
43 31 March 6 -1
51 40 April 11 4
60 48 May 15 9
69 57 June 21 14
76 63 July 24 17
76 63 August 24 17
70 58 September 21 15
61 49 October 16 9
52 40 November 11 4
44 31 December 7 0
57 44 Year 14 7

Days of Hot Weather in Cape Cod

It seldom gets really hot at Chatham on Cape Cod. In an average decade, there's just one day of 90-degree weather and the thermometer never makes it to 100 °F.

Spells of 70 degrees Fahrenheit or more can happen from May to October. Cape Cod's warmest months, July and August, see nearly every day with temperatures in at least the 70s and most nights dropping into the 60s.

Average days per month that Cape Cod is at least 60, 70 or 80 °F
  60 °F
16 °C
70 °F
21 °C
80 °F
27 °C
January 0 0 0
February 0 0 0
March 0 0 0
April 2 0 0
May 15 2 0
June 28 15 1
July 31 28 6
August 31 28 6
September 30 17 1
October 19 2 0
November 3 0 0
December 0 0 0
Year 159 92 14

How Often Cape Cod Has Cold Temperatures

Freezing temperatures at night can happen at Chatham in six months of the year, from November to April. Most winter nights there are below 33 degrees, though rarely down to zero Fahrenheit.

On average, 17 days a year have highs that remain below freezing. Weather this chilly is most common at Cape Cod during January, but can show up anytime from November to March.

Days per month on average on Cape Cod when the minimum temperature drops to 10, 20, or 32 °F or below
  10 °F
-12 °C
20 °F
-8 °C
32 °F
0 °C
January 3 9 23
February 1 7 21
March 0 3 16
April 0 0 2
May 0 0 0
June 0 0 0
July 0 0 0
August 0 0 0
September 0 0 0
October 0 0 0
November 0 0 5
December 0 2 16
Year 4 20 83
Reference

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Massachusetts Temperatures
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