Climate and monthly weather forecast
New Castle, PA

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The climate of New Castle

A major characteristic of New Castle's weather is that it falls under the Koppen's Dfb climate classification, adding to the climatic diversity in Pennsylvania, USA. This classification attributes the locale to a Humid Continental zone with no dry season; the summers are warm and welcoming. The geographical location and this climate type together shape an intriguing weather pattern.

A year-round temperature fluctuation prevails in New Castle with a maximum of 82°F (27.8°C) in July and a cold depth of 18.9°F (-7.3°C) in January. Humidity levels maintain consistency with little variation, averaging between 78 and 87% throughout the year. Precipitation similarly displays a consistent pattern, rainfall ranging from 2.24" (57mm) to 3.66" (93mm) from January to December. The city experiences snowy conditions with January and December witnessing the towering figures of 6.93" (176mm) and 4.69" (119mm) respectively.

Among the unique weather patterns of New Castle, July stands out for its warmth reaching up to 82°F (27.8°C), while January poses the challenging cold with its low temperature of 18.9°F (-7.3°C) and the highest snowfall of 6.93" (176mm). Another noteworthy element is December, which apart from its cold temperatures, experiences 2.68" (68mm) of rainfall, further intensifying the winter climate.

The best time to visit New Castle

A consensus among travelers and locals suggests that the period from June to August makes for the best time to visit New Castle. The city basks in decently high temperatures, hitting the maxima of 77.5°F (25.3°C) in June and 82°F (27.8°C) in July. Rainfall is also at its lowest levels during these months, ranging from 2.48" (63mm) to 3.35" (85mm). These months offer the longest daylight hours, peaking at 15.1 hours in June, and adequate sunshine, almost 9.9 hours in July, ensuring plenty of time to enjoy the local attractions. Additionally, the UV index is high at 6, calling for sun protection gear to maximize enjoyment.

The worst time to visit New Castle

While adventure seekers may disagree, the stretch from December to February marks the most challenging time, weather-wise, in New Castle. Temperatures plummet to their lowest, with January bearing the cold brunt dipping to 18.9°F (-7.3°C). Snowfall also accompanies, with 6.93" (176mm) and 4.69" (119mm) in January and December, respectively, leading to harsh conditions for outdoor activity. Daylight hours are at a minimum, at 9.3 hours during December, and sunshine is scarce. Visitors would need to brave the elements to enjoy New Castle during these months.

Spring weather in New Castle

Spring in New Castle commences with an average lowest temperature of 29.1°F (-1.6°C) in March, which improves to a pleasing 49.6°F (9.8°C) in May. This period sees an uptick in precipitation, with rainfall increasing from 2.76" (70mm) in March to 3.39" (86mm) in May. Surprisingly, snowfall starts disappearing with only 1.02" (26mm) in April and just an occasional 0.08" (2mm) in May.

Summer weather in New Castle

Summer kicks off in June with temperatures reaching a balmy 77.5°F (25.3°C), with July being the warmest month at 82°F (27.8°C). The season is peppered with moderate rainfall, hovering between 3.35" (85mm) and 2.48" (63mm) from June to August, and humidity remains steady at 78%. This period not only allows ample daylight, peaking at 15.1 hours in June, but also provides an abundance of sunshine, with the highest at 9.9 hours in July.

Autumn weather in New Castle

Autumn in New Castle brings a blend of cooling temperatures and increased precipitation. Temperatures start decreasing from 73.8°F (23.2°C) in September and fall to 33.1°F (0.6°C) in November. While October sees the highest rainfall of the season with 3.11" (79mm), light snowfall marks the onset of winter in November, with an occasional 2.83" (72mm). Despite this, the season offers considerable daylight- between 12.5 hours and 9.9 hours, accompanied by a reasonable amount of sunshine, 8.2 hours in September, dwindling down to 4.5 hours by November.

Winter weather in New Castle

Winter can be challenging in New Castle with temperatures hitting the year's lowest at 18.9°F (-7.3°C) in January, and never going beyond 38.1°F (3.4°C) in December. This season witnesses some of the heaviest snowfall, amounting to 6.93" (176mm) in January. December sees the year’s second-highest precipitation at 2.68" (68mm). Despite the daylight being limited to an average of 9.3 hours in December, the season can provide unique experiences for visitors who enjoy the winter chill.

Weather in January

Amidst the harsh winters of New Castle, Pennsylvania, January stands out with the highest relative humidity of 86%. Snowfall is a common phenomenon, covering the city in a mantle of white that contrasts beautifully with the frequent, overcast skies. Weather in January »

Weather in February

The grey, wintry landscape of New Castle continues into February, with temperatures that are only slightly warmer than January. The average low temperature remains likely below freezing, though marginally higher from 18.9°F (-7.3°C) witnessed in January to February's 20.7°F (-6.3°C). Weather in February »

Weather in March

March heralds the arrival of spring in New Castle, symbolizing a noticeable change in climatic conditions. Temperatures experience a substantial lift from the hard winter lows, breathing life into the frozen vegetation. Rainfall begins to edge ahead of snowfall, offering a respite from the relentless white landscape. Weather in March »

Weather in April

April sees a significant shift in weather patterns in New Castle, marking the end of the long winter spell. The coldest temperatures increase by almost 10°F (-12.2°C) from 29.1°F (-1.6°C) in March to 39.2°F (4°C) in April. This month brings a surge in day length and sunlight exposure, uplifting the spirits of the city's inhabitants. Weather in April »

Weather in May

With the advent of May, New Castle witnesses a noteworthy upsurge in temperatures. The transition from spring to early summer is marked by blossoming flowers and the chirping of birds returning after the winter. Rainfall continues to be a vital part of the weather equation, imparting a refreshing change to the atmosphere. Weather in May »

Weather in June

The climatic conditions of New Castle in June indicate the steady approach of summer. While it doesn't get as hot as other areas, the warmest average temperature increases slightly to 77.5°F (25.3°C). The increased hours of daylight illuminate the city for longer periods, providing ample opportunities for outdoor adventures. Weather in June »

Weather in July

July is the zenith of summer in New Castle, Pennsylvania, characterized by warm temperatures, sunny skies, and a cheerful ambience. These summer conditions peak with the highest average temperature registering at 82°F (27.8°C). The combination of reduced cloud cover and ample sunlight make this the ideal month for outdoor adventures, lake visits, and barbecues. Weather in July »

Weather in August

August brings a subtle decrease in temperature, signaling the nearing end of summer. While the descent from July's peak of 82°F (27.8°C) to 80.6°F (27°C) in this month is only slight, it indicates the gradual transition to the cooler months. Weather in August »

Weather in September

New Castle in September is a spectacle of vibrant fall colours, mild temperatures, and captivating beauty. Average temperatures take a dip from the 80.6°F (27°C) seen in August to a more comfortable 73.8°F (23.2°C). The shorter days and longer nights signal the beginning of fall and the end of summer fun. Weather in September »

Weather in October

October sees a further drop in temperature as autumn firmly establishes its presence in New Castle. Among the notable changes, the climb down from September's 73.8°F (23.2°C) to 60.4°F (15.8°C) stands out. The fall season is in full swing, with spectacular displays of colorful foliage adorning the cityscape. Weather in October »

Weather in November

November in New Castle, Pennsylvania brings colder temperatures and the first signs of the impending winter. The noticeable reduction from an average high of 60.4°F (15.8°C) in October to 47.7°F (8.7°C) in this month is a strong indication of the transition. Weather in November »

Weather in December

The arrival of December symbolizes the onset of winter in New Castle, which is marked by chilly temperatures, minimal daylight, and increased snowfall. The disparity in December's average high temperature from November's 47.7°F (8.7°C) to a much colder 38.1°F (3.4°C), reinforces the arrival of the frosty season. Weather in December »
Updated: Jun 4, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

New Castle's January weather, with an average high temperature of 31.5°F (-0.3°C) and an average low temperature of 18.9°F (-7.3°C), tends to be the coldest of the year.

How many days does it rain?

Throughout the year, there are 177.6 rainfall days, and 34.92" (887mm) of precipitation is accumulated.

When does it snow?

January through May, October through December are months with snowfall.

What is the snowiest month?

The month with the most snowfall is January, when snow falls for 18.6 days and typically aggregates up to 6.93" (176mm) of snow.

How much does it snow?

Throughout the year, there are 68.2 snowfall days, and 25.2" (640mm) of snow is accumulated.

What is the month with the least sunshine?

With an average of 2.5h of sunshine, January has the least sunshine of the year.

What is the most humid month in New Castle?

February is the most humid month, with an average relative humidity of 87%.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in New Castle, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

What is the least humid month?

April through August, with an average relative humidity of 78%, are the least humid months.

What is the wettest month?

The month with the most rainfall is June, when the rain falls for 17.9 days and typically aggregates up to 3.66" (93mm) of precipitation.

When it does not snow?

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

When are the longest days?

The month with the longest days is June, with an average of 15h and 6min of daylight.

What is the warmest month?

July registers as the month with the average highest temperatures, reaching 82°F (27.8°C) at its peak and 60.8°F (16°C) at the lowest.

What is the month with the highest UV index?

The month with the highest UV index is July, with an average maximum UV index of 6.

What month has the most sunshine?

August has the most sunshine of the year, with an average of 10h of sunshine.

What is the driest month?

November is the month with the least rainfall. Rain falls for 11.6 days and accumulates 2.24" (57mm) of precipitation.

What is the month with the shortest days?

With an average of 9h and 18min of daylight, December has the shortest days of the year.

What is the month with the lowest UV index?

December is the month with the lowest UV index, with an average maximum UV index of 1.
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Long-term
YearJFMAMJJASOND

Average temperature
New Castle, PA

Average temperature - New Castle, PA

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (31.5°F).

The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure
New Castle, PA

Average pressure - New Castle, PA

The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed
New Castle, PA

Average wind speed - New Castle, PA

The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is July (5.1mph).

Average humidity
New Castle, PA

Average humidity - New Castle, PA

The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are April, May, June, July and August (78%).

Average rainfall
New Castle, PA

Average rainfall - New Castle, PA

The wettest month (with the highest rainfall) is June (3.66").
The driest month (with the least rainfall) is November (2.24").

Average rainfall days
New Castle, PA

Average rainfall days - New Castle, PA

The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (8.8 days).

Average snowfall
New Castle, PA

Average snowfall - New Castle, PA

The month with the highest snowfall is January (6.93").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days
New Castle, PA

Average snowfall days - New Castle, PA

The month with the highest number of snowfall days is January (18.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
New Castle, PA

Average daylight / Average sunshine - New Castle, PA

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 18min).

The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 2h and 30min).

Average sunshine days
New Castle, PA

Average sunshine days - New Castle, PA

The month with the most sunshine days is November (13.5 days).
The month with the least sunshine days is February (7 days).

Average UV index
New Castle, PA

Average UV index - New Castle, PA

The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover
New Castle, PA

Average cloud cover - New Castle, PA

The month with the most cloud cover is January (Cloud cover 73).
The month with the least cloud cover is August (Cloud cover 36).

Average visibility
New Castle, PA

Average visibility - New Castle, PA

The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February and December (4mi).

New Castle, Pennsylvania, USA

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