May weather forecastWellfleet, MA

May

Weather in May

May presents a remarkable leap from the cool weather of April to the pleasant warmth typical of spring. The weather conditions are ideal for exploring the outdoors with low pressure and impressive visibility of 6 miles throughout the month. Marked by the highest relative humidity average of 84% throughout the year, May offers a moist environment, ideal for the proliferation of area’s flora. Nature enthusiasts and tourists are drawn to the city's beauty and blossoming plant life. As expected, June takes a leap towards the upcoming summer, promising increased daylight hours and warmer temperatures.

Temperature

Wellfleet observes a slight uplift in the average high-temperature with the onset of May, adjusting from April's frosty 46.8°F (8.2°C) to a cool 54.3°F (12.4°C). Nighttime temperatures record an average of 49.8°F (9.9°C) throughout May.

Humidity

In May, the average relative humidity is 84%.

Rainfall

In Wellfleet, in May, it is raining for 14.3 days, with typically 1.42" (36mm) of accumulated precipitation. Throughout the year, there are 136.1 rainfall days, and 17.24" (438mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Ocean temperature

In Wellfleet, the average seawater temperature in May is 49.1°F (9.5°C).
Note: Dipping into 49.1°F (9.5°C) below 50°F (10°C) is possible with the right protection; absent that, anticipate cold shock and hampered breathing. Swimming momentarily at 55.4°F (13°C) can be jarring.

Daylight

In Wellfleet, the average length of the day in May is 14h and 35min.
On the first day of the month, sunrise is at 5:35 am and sunset at 7:39 pm. On the last day of May, sunrise is at 5:07 am and sunset at 8:08 pm EDT.

Sunshine

The average sunshine in May in Wellfleet is 8.4h.

UV index

In Wellfleet, the average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 4 during May translates into the following directions:
Guard yourself - An obligation to protect skin and eyes from harm exists. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.

Updated: Jun 4, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Wellfleet in May has an average high-temperature of 54.3°F (12.4°C) and an average low-temperature of 49.8°F (9.9°C).

In Wellfleet, Massachusetts, the average relative humidity in May is 84%.

In May, the rain falls for 14.3 days. Throughout May, 1.42" (36mm) of precipitation is accumulated.

In Wellfleet, Massachusetts, snow does not fall in May through October.

In May, it doesn't snow. April is the latest month when it typically snows.

In Wellfleet, the average seawater temperature in May is 49.1°F (9.5°C). Swimming in 49.1°F (9.5°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

The average day length in May is 14h and 35min.

In May, on the first day of the month, sunrise is at 5:35 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 5:07 am and sunset at 8:08 pm EDT.

In May, the average sunshine duration is 8.4h.

The average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a moderate vulnerability from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A May J J A S O N D

Apr

May

Jun

Average high temperature

46.8°F

54.3°F

62.4°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

16.3mph

14.1mph

13.2mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

0.8

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

14.8

16.3

Average UV index

Average cloud cover

Average visibility

Average temperature in May
Wellfleet, MA

Average high temperature in May: 54.3°F

The warmest month (with the highest average high temperature) is August (71.1°F).
The month with the lowest average high temperature is January (38.7°F).

Average low temperature in May: 49.8°F

The month with the highest average low temperature is August (67.6°F).
The coldest months (with the lowest average low temperature) are January and February (31.6°F).

Average pressure in May
Wellfleet, 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
Wellfleet, MA

Average wind speed in May: 13.2mph

The windiest month (with the highest average wind speed) is January (18.5mph).
The calmest months (with the lowest average wind speed) are July and August (11.6mph).

Average humidity in May
Wellfleet, MA

Average humidity in May: 84%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is November (74%).

Average rainfall in May
Wellfleet, MA

Average rainfall in May: 1.42"

The wettest month (with the highest rainfall) is October (2.17").
The driest months (with the least rainfall) are February and November (1.18").

Average rainfall days in May
Wellfleet, MA

Average rainfall days in May: 14.3 days

The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is February (7.3 days).

Average snowfall in May
Wellfleet, MA

Average snowfall in May: 0"

The month with the highest snowfall is February (0.94").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in May
Wellfleet, MA

Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (6.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in May
Wellfleet, 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
Wellfleet, 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 36min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).

Average sunshine days in May
Wellfleet, MA

Average sunshine days in May: 15 days

The month with the most sunshine days is August (18.2 days).
The month with the least sunshine days is December (13.1 days).

Average UV index in May
Wellfleet, 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
Wellfleet, MA

Average cloud cover in May: 45

The month with the most cloud cover is December (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 28).

Average visibility in May
Wellfleet, 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).