May weather forecast
Hyannis, MA

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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 embrace of May brings a minor uplift in the average high-temperature in Hyannis, shifting from a chilly 47.1°F (8.4°C) in April to a refreshing 55.4°F (13°C). Hyannis reports an average low temperature of 50.9°F (10.5°C) in May, a minor decrease from the day's highs.

Humidity

The average relative humidity in May in Hyannis is 83%.

Rainfall

In Hyannis, in May, it is raining for 14.9 days, with typically 2.2" (56mm) of accumulated precipitation. Throughout the year, in Hyannis, there are 157.2 rainfall days, and 31.77" (807mm) of precipitation is accumulated.

Snowfall

May through November are months without snowfall in Hyannis.

Ocean temperature

In May, the average ocean temperature 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

The average length of the day in May in Hyannis is 14h and 33min.
On the first day of May, sunrise is at 5:36 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 5:09 am and sunset at 8:08 pm EDT.

Sunshine

The average sunshine in May in Hyannis is 8.7h.

UV index

In Hyannis, the average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: In May, a daily UV index of 4 turns into the following recommendations:
Undertake precautions - It is suggested to shield oneself from sunburn. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
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Frequently asked questions

What is the average May temperature in Hyannis?

May temperatures in Hyannis, Massachusetts, vary between a high-temperature of 55.4°F (13°C) and a low-temperature of 50.9°F (10.5°C).

What is the average humidity in May in Hyannis?

The average relative humidity in May in Hyannis, Massachusetts, is 83%.

How many days does it rain in May in Hyannis?

In Hyannis, Massachusetts, in May, during 14.9 rainfall days, 2.2" (56mm) of precipitation is typically accumulated.

When it does not snow in Hyannis?

In Hyannis, snow does not fall in May through November.

Does it snow in Hyannis in May?

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

What is the ocean temperature in May in Hyannis?

In Hyannis, Massachusetts, the average seawater temperature in May is 49.1°F (9.5°C). At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

What is the average length of the day in May in Hyannis?

In May, the average day length in Hyannis, Massachusetts, is 14h and 33min.

When are sunrise and sunset in May in Hyannis?

In May, on the first day of the month, sunrise is at 5:36 am and sunset at 7:39 pm. On the last day of the month, in Hyannis, Massachusetts, sunrise is at 5:09 am and sunset at 8:08 pm EDT.

How long on average sun shines in May in Hyannis?

In May, the average sunshine duration is 8.7h.

What is the UV index intensity in May in Hyannis?

The average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium health risk from exposure to the Sun's UV radiation.
Today
Tomorrow
Long-term
YearJFMAMayJJASOND
Apr
May
Jun
Average high temperature
47.1°F 8.4°C
55.4°F 13°C
63.9°F 17.7°C
Average low temperature
42.4°F 5.8°C
50.9°F 10.5°C
59.4°F 15.2°C
Average pressure
29.98" 761mmHg
30.02" 763mmHg
29.93" 760mmHg
Average wind speed
14.1mph 22.7km/h
12.2mph 19.6km/h
11.4mph 18.3km/h
Average max. wind speed
15mph 24.1km/h
13mph 20.9km/h
12.1mph 19.5km/h
Average wind speed gusts
24.4mph 39.3km/h
22.3mph 35.9km/h
20.7mph 33.3km/h
Average humidity
79%
83%
83%
Average rainfall
3.03" 77mm
2.2" 56mm
2.24" 57mm
Average rainfall days
15.8
14.9
12.9
Average snowfall
0.12" 3mm
0" 0mm
0" 0mm
Average snowfall days
0.6
0
0
Average sea temperature
43.5°F 6.4°C
49.2°F 9.6°C
57.7°F 14.3°C
Average daylight
13h 2min
14h 4min
15h 1min
Average sunshine
8h 2min
8h 4min
9h 3min
Average sunshine days
12.7
14.3
15.1
Average UV index
3
4
5
Average cloud cover
45%
43%
36%
Average visibility
6mi 9.7km
6mi 9.7km
6mi 9.7km

Average temperature in May
Hyannis, MA

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).

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Average pressure in May
Hyannis, MA

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).

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Average wind speed in May
Hyannis, MA

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).

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Average humidity in May
Hyannis, MA

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%).

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Average rainfall in May
Hyannis, MA

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").

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Average rainfall days in May
Hyannis, MA

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).

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Average snowfall in May
Hyannis, MA

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").

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Average snowfall days in May
Hyannis, MA

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).

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Average sea temperature in May
Hyannis, MA

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).

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Average daylight in May /
Average sunshine in May
Hyannis, MA

Average daylight in May / Average sunshine in May - Hyannis, MA
  • Average daylight in May: 14h and 4min

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 4min

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).

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Average sunshine days in May
Hyannis, MA

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).

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Average UV index in May
Hyannis, MA

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).

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Average cloud cover in May
Hyannis, MA

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).

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Average visibility in May
Hyannis, MA

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).

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Hyannis, Massachusetts, USA

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