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.
| 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.
| 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.
| 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.