May weather forecastChatham, MA
May
Weather in May
May in Chatham is a delightful month, as it transitions towards the eagerly awaited summer season. The highest point of temperature climbs to an average of 54.3°F (12.4°C), boosting the bloom of local flora and fauna. This month also signifies a slight decrease in rainfall than April, marking a shift from the showery spring to a much drier summer. The increasingly warm weather coupled with the lengthening days spells out ideal conditions for outdoor recreation. Heading into the end of May, the weather makes further strides towards the summertime, with rising temperatures and dwindling rainfall.Temperature
The start of May brings a subtle shift in the average high-temperature, edging up from April's chilly 46.9°F (8.3°C) to a fresh 54.3°F (12.4°C). In May, Chatham experiences a marginal drop in temperature, with averages of 50.5°F (10.3°C) at night.Humidity
In May, the average relative humidity is 84%.Rainfall
In Chatham, during May, the rain falls for 14.6 days and regularly aggregates up to 1.81" (46mm) of precipitation. Throughout the year, there are 142.4 rainfall days, and 22.09" (561mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Ocean temperature
In May, the average ocean temperature is 48.2°F (9°C).Note: It is life-risking to swim in 48.2°F (9°C). Briefly staying in 55.4°F (13°C) waters feels unsettling, and temperatures below 50°F (10°C) might result in cold shock and loss of breath control, hinging on personal endurance.
Daylight
In Chatham, the average length of the day in May is 14h and 33min.On the first day of the month, sunrise is at 5:35 am and sunset at 7:38 pm. On the last day of May, sunrise is at 5:07 am and sunset at 8:07 pm EDT.
Sunshine
In Chatham, the average sunshine in May is 8.4h.UV index
In May, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 4 during May translates into these guidelines:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Chatham, MA
- Average high temperature in May: 54.3°F
The warmest month (with the highest average high temperature) is August (71.6°F).
The months with the lowest average high temperature are January and February (39°F).
- Average low temperature in May: 50.5°F
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (31.6°F).
Average pressure in May
Chatham, MA
- Average pressure in May: 30.02"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in May
Chatham, MA
- Average wind speed in May: 13.2mph
The windiest month (with the highest average wind speed) is January (18mph).
The calmest month (with the lowest average wind speed) is August (11.4mph).
Average humidity in May
Chatham, MA
- Average humidity in May: 84%
The months with the highest relative humidity are June and July (85%).
The month with the lowest relative humidity is November (74%).
Average rainfall in May
Chatham, MA
- Average rainfall in May: 1.81"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is November (1.46").
Average rainfall days in May
Chatham, MA
- Average rainfall days in May: 14.6 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is February (8.3 days).
Average snowfall in May
Chatham, MA
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Chatham, MA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in May
Chatham, MA
- Average sea temperature in May: 48.3°F
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is March (39.8°F).
Average daylight in May /
Average sunshine in May
Chatham, MA
- Average daylight in May: 14h and 36min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in May: 8h and 24min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in May
Chatham, MA
- Average sunshine days in May: 14.8 days
The month with the most sunshine days is August (17.6 days).
The month with the least sunshine days is January (13 days).
Average UV index in May
Chatham, MA
- Average UV index in May: 4
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in May
Chatham, MA
- Average cloud cover in May: 45
The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in May
Chatham, MA
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
