May weather forecastHyannis, MA
May
Weather in May
May in Hyannis, Massachusetts heralds the rapid onset of summer, differing substantially from the cooler conditions of April. Sunshine hours see an appreciable enhancement, contributing to higher UV indexes. As the summer nears, the sea temperatures rise to a welcoming 49.2°F (9.6°C), encouraging beach visits and water-based activities. It is also remarkable to note the increase in daylight hours throughout May. Concurrently, the rainfall tends to decrease in May, making it more hospitable than the preceding month.Temperature
The coming of May brings a minor shift in Hyannis's weather, with average high-temperatures adjusting from April's chilly 47.1°F (8.4°C) to a refreshing 55.4°F (13°C). In Hyannis, the nightly May temperatures experience a slight descent from daily highs to an average low of 50.9°F (10.5°C).Humidity
In May, the average relative humidity is 83%.Rainfall
In Hyannis, in May, during 14.9 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. Throughout the year, there are 157.2 rainfall days, and 31.77" (807mm) of precipitation is accumulated.Snowfall
May through November are months without snowfall.Ocean temperature
In Hyannis, the average seawater temperature in May is 49.1°F (9.5°C).Note: Swimming in 49.1°F (9.5°C) at temperatures under 50°F (10°C) requires thermal swimsuits; otherwise, one can face cold shock and breathing difficulty. Even brief immersion at 55.4°F (13°C) feels frosty.
Daylight
In May, the average length of the day is 14h and 33min.On the first day of the month, sunrise is at 5:36 am and sunset at 7:39 pm. On the last day of May, sunrise is at 5:09 am and sunset at 8:08 pm EDT.
Sunshine
In May, the average sunshine is 8.7h.UV index
In Hyannis, the average daily maximum UV index in May is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In May, the UV index of 4 transforms into the following advice:
Prioritize safety - Suggestions to prevent sun damage are offered. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Hyannis, MA
- Average high temperature in May: 55.4°F
The warmest month (with the highest average high temperature) is August (72.5°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in May: 50.9°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 (30.4°F).
Average pressure in May
Hyannis, 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
Hyannis, MA
- Average wind speed in May: 12.2mph
The windiest month (with the highest average wind speed) is January (16.5mph).
The calmest month (with the lowest average wind speed) is August (10.6mph).
Average humidity in May
Hyannis, MA
- Average humidity in May: 83%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is November (74%).
Average rainfall in May
Hyannis, MA
- Average rainfall in May: 2.2"
The wettest month (with the highest rainfall) is October (3.7").
The driest month (with the least rainfall) is August (1.73").
Average rainfall days in May
Hyannis, MA
- Average rainfall days in May: 14.9 days
The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is February (10.3 days).
Average snowfall in May
Hyannis, MA
- Average snowfall in May: 0"
The month with the highest snowfall is March (1.93").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in May
Hyannis, MA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (7.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in May
Hyannis, MA
- Average sea temperature in May: 49.2°F
The best month for swimming (with the highest average sea temperature) is August (67.5°F).
The coldest month (with the lowest average sea temperature) is March (39°F).
Average daylight in May /
Average sunshine in May
Hyannis, MA
- Average daylight in May: 14h and 36min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in May: 8h and 42min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in May
Hyannis, MA
- Average sunshine days in May: 14.3 days
The month with the most sunshine days is August (17.7 days).
The month with the least sunshine days is February (11.4 days).
Average UV index in May
Hyannis, 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
Hyannis, MA
- Average cloud cover in May: 43
The months with the most cloud cover are February and December (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in May
Hyannis, 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).
