The hottest month in Massachusetts is July when the average maximum temperature is 26°, average temperature is 22° and average minimum temperature is 18°.
The coolest month in Massachusetts is January when the average maximum temperature is 3°, average temperature is -0° and average minimum temperature is -4°.
The longest days in Massachusetts are in June, with an average of 15.2 hours of daylight per day. December has the shortest days with an average of 9.1 hours of daylight per day.
The sunniest days in Massachusetts are in May which has the most hours of sunshine per day with an average of 6.5 hours of sunshine per day, making it a quite sunny month with some cloud cover. December has the least sunshine with an average of 4.8 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in July when it reaches 9.4 and lowest in December when it reaches 1.4.
An ultraviolet index reading of 8 to 10 indicates a very high risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 15 minutes. Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in Massachusetts are found in August when they peak at 22° and lowest in January when they dip to 4°.
The sea is best for swimming between June and December when the temperature is above 14° which is cold for swimming, a full wet suit is required to spend any length of time in the sea.
The wettest month in Massachusetts is August with 19.5cm of rain and December has the most days of rain with 15.8 days with some rain, a wet time to visit the beach.
The driest month in Massachusetts is July with 7.4cm of rain and February has the fewest days of rain with 12.2 days with some rain, a slightly wet time to visit the beach.
The most humid month in Massachusetts is July with a dew point (an indicator of humidity) of 20° which is somewhat uncomfortable for most people in cities but fine on a beach.
The least humid month in Massachusetts is February with a dew point of -1° which is a bit dry for some.
The most windy month in Massachusetts is February when the average maximum windspeed is 27kmh and the average wind speed is 15kmh.
The least windy month in Massachusetts is August when the average maximum windspeed is 20kmh and the average wind speed is 10kmh.