May weather forecast
New Castle, NH

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Weather in May

May brings a palpable shift towards warmer conditions in New Castle. An increase in temperature, along with a significant rise in sea temperature to 47.3°F (8.5°C), indicates the arrival of summer. Rainfall becomes less frequent, although the volume of precipitation remains relatively high. However, the number of sunshine hours increases significantly, making the days brighter and clearer. Despite the evolving conditions, the humidity levels stay fairly constant.

Temperature

The shift from April to May is marked by an increase in the average high-temperature, moving from a cool 51.1°F (10.6°C) to an enjoyable 61°F (16.1°C). In May, the temperature drops to an average of 48°F (8.9°C) at night.

Humidity

In May, the average relative humidity is 78%.

Rainfall

In New Castle, in May, during 14.8 rainfall days, 1.97" (50mm) of precipitation is typically accumulated. Throughout the year, there are 144.2 rainfall days, and 27.48" (698mm) of precipitation is accumulated.

Snowfall

In New Castle, snow does not fall in May through September.

Ocean temperature

In May, the average ocean temperature is 47.3°F (8.5°C).
Note: Swimming in 47.3°F (8.5°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

In May, the average length of the day is 14h and 41min.
On the first day of the month, sunrise is at 5:35 am and sunset at 7:44 pm. On the last day of May, sunrise is at 5:06 am and sunset at 8:15 pm EDT.

Sunshine

In May, the average sunshine is 8.5h.

UV index

The average daily maximum UV index in May is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the average person.
Note: The maximum UV index, 5 during May, leads to the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Updated: Jul 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are May temperatures?

In New Castle, in May, the average high-temperature is 61°F (16.1°C), and the average low-temperature is 48°F (8.9°C).

What is the average humidity in May?

In New Castle, the average relative humidity in May is 78%.

How much does it rain in May?

In New Castle, during May, the rain falls for 14.8 days and regularly aggregates up to 1.97" (50mm) of precipitation.

When it does not snow?

May through September are months without snowfall.

Does it snow in May?

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

What is the ocean temperature in May?

In New Castle, the average seawater temperature in May is 47.3°F (8.5°C). Swimming in 47.3°F (8.5°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in May?

In May, the average day length is 14h and 41min.

When is the sunrise / sunset in May?

In May, on the first day of the month, sunrise is at 5:35 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 5:06 am and sunset at 8:15 pm EDT.

How long on average sun shines in May?

In New Castle, the average sunshine duration in May is 8.5h.

What is the UV index intensity in May?

In May, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
New Castle, NH

Average temperature in May - New Castle, NH
  • Average high temperature in May: 61°F

The warmest month (with the highest average high temperature) is July (76.3°F).
The month with the lowest average high temperature is January (31.8°F).

  • Average low temperature in May: 48°F

The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).

Average pressure in May
New Castle, NH

Average pressure in May - New Castle, NH
  • Average pressure in May: 30"Hg

The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in May
New Castle, NH

Average wind speed in May - New Castle, NH
  • Average wind speed in May: 8mph

The windiest month (with the highest average wind speed) is January (11.7mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).

Average humidity in May
New Castle, NH

Average humidity in May - New Castle, NH
  • Average humidity in May: 78%

The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are April and November (75%).

Average rainfall in May
New Castle, NH

Average rainfall in May - New Castle, NH
  • Average rainfall in May: 1.97"

The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is September (1.54").

Average rainfall days in May
New Castle, NH

Average rainfall days in May - New Castle, NH
  • Average rainfall days in May: 14.8 days

The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (7.5 days).

Average snowfall in May
New Castle, NH

Average snowfall in May - New Castle, NH
  • Average snowfall in May: 0"

The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in May
New Castle, NH

Average snowfall days in May - New Castle, NH
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average sea temperature in May
New Castle, NH

Average sea temperature in May - New Castle, NH
  • Average sea temperature in May: 47.3°F

The best month for swimming (with the highest average sea temperature) is August (65.6°F).
The coldest month (with the lowest average sea temperature) is March (38.5°F).

Average daylight in May /
Average sunshine in May
New Castle, NH

Average daylight in May / Average sunshine in May - New Castle, NH
  • Average daylight in May: 14h and 4min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in May: 8h and 3min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).

Average sunshine days in May
New Castle, NH

Average sunshine days in May - New Castle, NH
  • Average sunshine days in May: 14.8 days

The month with the most sunshine days is September (16.8 days).
The month with the least sunshine days is April (13.2 days).

Average UV index in May
New Castle, NH

Average UV index in May - New Castle, NH
  • Average UV index in May: 5

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
New Castle, NH

Average cloud cover in May - New Castle, NH
  • Average cloud cover in May: 45

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in May
New Castle, NH

Average visibility in May - New Castle, NH
  • 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).

New Castle, New Hampshire, USA

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