May weather forecast
New Castle, DE

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Weather in May

May in New Castle signifies the true arrival of summer. Weather in this month is characterized by the highest average low temperature of 55°F (12.8°C) observed in the year so far. Residents enjoy pleasant mornings and late evenings thanks to the warm weather. The days become longer, and the city experiences a good amount of sunshine. Cloud activity decreases, allowing the sun to shine brighter and longer.

Temperature

May's arrival signals an increase in average high-temperatures, moving from April's enjoyable 61.7°F (16.5°C) to a pleasant 72°F (22.2°C). During May, the nighttime temperature in New Castle averages to a fresh 55°F (12.8°C).

Humidity

In New Castle, the average relative humidity in May 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.

Ocean temperature

In New Castle, in May, the average water temperature is 54°F (12.2°C).
Note: Engaging in a swim in 54°F (12.2°C) can threaten life. Brief exposure to 55.4°F (13°C) waters is uneasy, and submersion below 50°F (10°C) can lead to cold shock and disrupted breathing patterns, varying by individual.

Daylight

In May, the average length of the day is 14h and 23min.
On the first day of May, sunrise is at 6:01 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 5:36 am and sunset at 8:23 pm EDT.

Sunshine

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

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index in New Castle. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 6 in May interprets into the following advice:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
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Frequently asked questions

What is the usual temperature for New Castle in May?

During May, New Castle experiences an average high-temperature of 72°F (22.2°C) and a low-temperature of 55°F (12.8°C).

What is the average humidity in May in New Castle?

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

How much does it rain in New Castle in May?

In New Castle, during May, the rain falls for 16.8 days and regularly aggregates up to 2.05" (52mm) of precipitation.

When it does not snow in New Castle?

May through October are months without snowfall.

Does it snow in New Castle in May?

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

How cold is the water 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 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 New Castle?

In May, the average day length in New Castle, Delaware, is 14h and 23min.

When is the sunrise / sunset in May in New Castle?

On the first day of May in New Castle, sunrise is at 6:01 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 5:36 am and sunset at 8:23 pm EDT.

How long on average sun shines in May in New Castle?

The average sunshine duration in May is 8.7h.

What is the month with the highest UV index in New Castle?

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

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

In May, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unsafe 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, DE

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).

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Average pressure in May
New Castle, DE

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

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

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Average wind speed in May
New Castle, DE

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).

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Average humidity in May
New Castle, DE

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%).

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Average rainfall in May
New Castle, DE

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").

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Average rainfall days in May
New Castle, DE

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).

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Average snowfall in May
New Castle, DE

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

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

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Average snowfall days in May
New Castle, DE

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).
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
New Castle, DE

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).

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

Average daylight in May / Average sunshine in May - New Castle, DE
  • Average daylight in May: 14h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in May: 8h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).

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Average sunshine days in May
New Castle, DE

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).

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Average UV index in May
New Castle, DE

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

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

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Average cloud cover in May
New Castle, DE

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

The 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).

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Average visibility in May
New Castle, DE

Average visibility in May - New Castle, DE
  • 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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New Castle, Delaware, USA

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