May weather forecast and climate
New Castle, DE

The last month of the spring, May, is an agreeable month in New Castle, Delaware, with average temperature fluctuating between 72°F (22.2°C) and 55°F (12.8°C).

Temperature

In May, the average high-temperature increases, from a comfortable 61.7°F (16.5°C) in April, to an agreeable 72°F (22.2°C). In May, in New Castle, the average low-temperature is 55°F (12.8°C).

Humidity

In New Castle, the average relative humidity is 77%.

Rainfall

In New Castle, in May, during 16.8 rainfall days, 2.05" (52mm) of precipitation is typically accumulated. In New Castle, during the entire year, the rain falls for 143.2 days and collects up to 21.89" (556mm) of precipitation.

Snowfall

May through October are months without snowfall in New Castle.

Ocean temperature

In May, the average ocean temperature in New Castle is 54°F (12.2°C).
Note: Swimming in 54°F (12.2°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.

Daylight

In May, the average length of the day in New Castle is 14.4h.

Sunshine

The average sunshine in May is 8.7h.

UV index

Months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high threat to health from the exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 6 transform into the following instructions:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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.

What is the temperature in May in New Castle?

The average high-temperature, in May, in New Castle, Delaware, is 72°F (22.2°C), while the average low-temperature is 55°F (12.8°C).

What is the average humidity in May in New Castle?

The average relative humidity in May in New Castle is 77%.

How many days does it rain in May in New Castle?

In New Castle, Delaware, in May, during 16.8 rainfall days, 2.05" (52mm) of precipitation is typically accumulated.

Does it snow in New Castle in May?

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

When it does not snow in New Castle?

In New Castle snow does not fall in May through October.

What is the ocean temperature in May in New Castle?

In New Castle, the average seawater temperature in May is 54°F (12.2°C). Swimming in 54°F (12.2°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.

How many hours of daylight does New Castle have in May?

In New Castle, Delaware, the average length of the day in May is 14.4h.

How many hours of sunshine does New Castle have in May?

In New Castle, Delaware, the average sunshine in May is 8.7h.

What are the months with the highest UV index in New Castle?

May through August, with an average maximum UV index of 6, are months with the highest UV index in New Castle.

How high is the UV index in May in New Castle?

In New Castle, Delaware, the average daily maximum UV index in May is 6. A UV Index value of 6 to 7 symbolizes a high health risk from unsafe exposure to the Sun's UV rays.
Average temperature in May - New Castle, DE
  • Average high temperature in May: 72°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (37.8°F).

  • Average low temperature in May: 55°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).

Average pressure in May - New Castle, DE
  • Average pressure in May: 30.01"

The month with the highest atmospheric pressure is November (30.13").
The month with the lowest atmospheric pressure is June (29.94").

Average wind speed in May - New Castle, DE
  • Average wind speed in May: 6.9mph

The windiest months (with the highest average wind speed) are February and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).

Average humidity in May - New Castle, DE
  • Average humidity in May: 77%

The month with the highest relative humidity is October (78%).
The month with the lowest relative humidity is April (72%).

Average rainfall in May - New Castle, DE
  • Average rainfall in May: 2.05"

The wettest month (with the highest rainfall) is August (2.83").
The driest month (with the least rainfall) is January (1.38").

Average rainfall days in May - New Castle, DE
  • Average rainfall days in May: 16.8 days

The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (7.8 days).

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

The month with the highest snowfall is January (1.69").
Months with the least snowfall are May, June, July, August, September and October (0").

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

The month with the highest number of snowfall days is January (5.2 days).
Months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in May - New Castle, DE
  • Average sea temperature in May: 53.9°F

The best month for swimming (with the highest average sea temperature) is August (76.3°F).
The coldest month (with the lowest average sea temperature) is February (40.9°F).

Average daylight in May / Average sunshine in May - New Castle, DE
  • Average daylight in May: 14.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.4h).

  • Average sunshine in May: 8.7h

The month with the most sunshine is July (Average sunshine: 10.8h).
The month with the least sunshine is February (Average sunshine: 4.9h).

Average sunshine days in May - New Castle, DE
  • Average sunshine days in May: 11.8 days

The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is May (11.8 days).

Average UV index in May - New Castle, DE
  • Average UV index in May: 6

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 2).

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

Months with the most cloud cover are February and March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).

Average visibility in May - New Castle, DE
  • Average visibility in May: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).