Climate and monthly weather forecastNew Castle, NH
Climate and monthly weather forecast
The climate of New Castle
New Castle, nestled in the state of New Hampshire, USA, is characterized by a Humid Continental climate (Dfb), under the Köppen climate classification. This climate predominantly presents no dry season, with warm summers followed by cold, snow-clad winters.Navigating through the year, the weather of New Castle undergoes significant variation. With temperature fluctuations from a chilly 21.2°F (-6°C) in January to a warm 76.3°F (24.6°C) in July, New Castle experiences a considerable temperature range. Humidity levels tend to maintain a more or less uniform level throughout the year, ranging narrowly from 75% to 80%. Rainfall presents a relatively stable pattern with a somewhat higher concentration during the autumn months. Snow can be expected from November through April, with January and December experiencing the highest snowfall of 4.02" (102mm) and 3.9" (99mm) respectively.
Unique weather patterns in New Castle include the lack of true dry months, with even the least rainy month in September averaging 1.54" (39mm) of precipitation. While summers are relatively warm with highest temperatures registered at 76.3°F (24.6°C) in July, winter can be quite cold, with January registering the lowest temperature of 21.2°F (-6°C).
The best time to visit New Castle
Given the diversity of the climate, the ideal time to visit New Castle is between May and September. The temperatures during these months average between a pleasant 51.1°F (10.6°C) to 75.7°F (24.3°C). With longer sunlight hours ranging from 13.4 hours to 15 hours and relative humidity standing at an average 78-80%, the conditions are optimal for outdoor recreational activities and sightseeing.The worst time to visit New Castle
Tourists would do well to avoid planning a trip to New Castle during the winter months between November and March. Cold weather, coupled with an average snowfall ranging from 0.91" (23mm) to 4.02" (102mm) and much shorter daylight hours - from 9.1 hours to 10.6 hours, make these months less hospitable for visitors.Spring weather in New Castle
Spring ushers in warmer temperatures to New Castle with the climate ranging from 40.5°F (4.7°C) in March to 61°F (16.1°C) in May. The warming weather conditions are accompanied by increasing rainfall, with April seeing an average precipitation of 2.48" (63mm). However, spring also brings extended daylight hours, starting with 12 hours in March and gradually increasing to 14.7 hours by May.Summer weather in New Castle
Summers in New Castle, from June to August, have an average high temperature from 69.3°F (20.7°C) to 76.3°F (24.6°C), making them moderately warm. This period also witnesses an increased rain volume of 2.6" (66mm) in June. Sunshine hours range from 9.2 hours to 10.6 hours, with the most extensively sunny period being in July, making the season hospitable for various outdoor activities.Autumn weather in New Castle
Autumn in New Castle, spanning September through November, sees a drop in temperature, from a warm 69.1°F (20.6°C) in September to 47.1°F (8.4°C) in November. The season also brings the year’s highest rainfall, with 2.83" (72mm) recorded in October. Despite the decrease in temperature and increase in rainfall, the season witnesses good daylight with sunshine hours ranging from 6.1 hours to 8.6 hours.Winter weather in New Castle
Winter in New Castle, beginning in December and ending in February, is known for its cold temperatures and snowfall. With temperatures averaging between 21.2°F (-6°C) to 34.2°F (1.2°C), winter can be brisk and chilly. Snowfall is a common occurrence, peaking with an average of 4.02" (102mm) in January. This season is marked by shorter daylight hours with sun shining for only between 4.8 hours to 5.1 hours. Despite the cold and the snow, the charm of the winter season can be appealing to the lovers of the winter landscape.Weather in January
January in New Castle, New Hampshire, witnesses the coldest month of the year, with the lowest temperatures plunging to 21.2°F (-6°C). The winter chill is accompanied by a decent amount of precipitation, resulting in several snowy days. Weather in January »Weather in February
By February, New Castle experiences a slight increase in temperatures, but it does not alleviate the winter severity much. Significant snowfall continues from January, although the frequency of snowy days and total snowfall both see a marginal reduction. Weather in February »Weather in March
With a rise to 40.5°F (4.7°C), March offers slightly warmer weather compared to the preceding months. Both snowfall and snowy days see a considerable decrease, indicating the onset of spring. Still, the lingering chill of winter makes the sea temperature too low for a comfortable swim. Weather in March »Weather in April
April exhibits a prominent transition towards spring, as the temperature soars to 51.1°F (10.6°C). The chance of experiencing snowfall reduces drastically, paving the way for more frequent rainfall. As the sea starts warming up, the number of cloudy days decreases, signifying clearer skies. Weather in April »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. Weather in May »Weather in June
As summer takes full swing in June, New Castle sees its temperatures reaching a comfortable 69.3°F (20.7°C). A remarkable increase in daylight and sunshine hours ensures pleasant, bright days. Rainy days might be at their peak in the year, but sea temperatures are warm enough for summer water activities. Weather in June »Weather in July
July is the warmest month in New Castle with a maximum temperature of 76.3°F (24.6°C). Sea temperature, too, peaks at this time, enticing locals and tourists to indulge in beachside activities. Despite the frequent rainfall, the month enjoys its longest sunshine duration, offering radiant and warm days. Weather in July »Weather in August
In August, the temperature remains relatively stable, with little difference from July. Rainfall becomes less frequent, and the number of sunshine hours continues to be high. Clear skies provide unlimited visibility, enhancing the overall summer feel. Weather in August »Weather in September
September marks the transition from summer to fall in New Castle. The temperature begins to drop, but pleasant warmth continues to linger. While the frequency of rainfall increases once again, the overall precipitation sees a decline. Weather in September »Weather in October
October brings a noticeable change in New Castle weather, with temperatures dropping to 57.9°F (14.4°C). The fall's influence is evident as daylight and sunshine hours decrease noticeably. In spite of a significant rise in rainfall, the sea temperature takes a dip, making water sports less appealing. Weather in October »Weather in November
In November, New Castle's atmosphere turns colder, indicating winter is around the corner. Snowfall returns towards the end of the month, offering a stark contrast to the rain-dominant climate of previous months. As daylight hours continue to decrease, so does the duration of sunshine. Weather in November »Weather in December
December brings the chill of winter back to New Castle, with temperatures falling to 37.6°F (3.1°C). Increased snowfall towards the end of the year creates a wintry spectacle, especially on the many snowy days this month encounters. Weather in December »Updated: Jul 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The coldest time of the year is January, with temperatures averaging a high of 31.8°F (-0.1°C) and a low of 21.2°F (-6°C).
Throughout the year, there are 144.2 rainfall days, and 27.48" (698mm) of precipitation is accumulated.
Months with snowfall are January through April, October through December.
January is the month with the most snowfall. Snow falls for 8.8 days and accumulates 4.02" (102mm) of snow.
Throughout the year, there are 35.2 snowfall days, and 16.97" (431mm) of snow is accumulated.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
February and December, with an average of 4.8h of sunshine, are months with the least sunshine.
March is the month with the coldest seawater, with an average ocean temperature of 38.5°F (3.6°C).
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.
April and November, with an average relative humidity of 75%, are the least humid months.
May through September are months without snowfall.
The most humid month is June, with an average relative humidity of 80%.
The month with the longest days is June, with an average of 15h and 18min of daylight.
New Castle's July weather reaches an average high of 76.3°F (24.6°C) and an average low of 62.6°F (17°C), making it the warmest month.
July and August, with an average maximum UV index of 6, are months with the highest UV index.
August is the month with the warmest seawater, with an average ocean temperature of 65.7°F (18.7°C).
The month with the most sunshine is August, with an average of 10.6h of sunshine.
The month with the least rainfall in New Castle is September, when the rain falls for 11.3 days and typically collects 1.54" (39mm) of precipitation.
The month with the most rainfall is October, when the rain falls for 13.3 days and typically aggregates up to 2.83" (72mm) of precipitation.
The month with the shortest days is December, with an average of 9h and 6min of daylight.
Average temperature
New Castle, NH
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).
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
New Castle, NH
- Average pressure in January:
29.99"Hg - Average pressure in February:
29.98"Hg - Average pressure in March:
30.02"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
30"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.94"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.06"Hg - Average pressure in December:
30.03"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
New Castle, NH
- Average wind speed in January:
11.7mph - Average wind speed in February:
11.2mph - Average wind speed in March:
10.7mph - Average wind speed in April:
9.6mph - Average wind speed in May:
8mph - Average wind speed in June:
7.4mph
- Average wind speed in July:
6.6mph - Average wind speed in August:
6.7mph - Average wind speed in September:
7.6mph - Average wind speed in October:
9.3mph - Average wind speed in November:
9.9mph - Average wind speed in December:
10.8mph
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
New Castle, NH
The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are April and November (75%).
Average rainfall
New Castle, NH
- Average rainfall in January:
2.05" - Average rainfall in February:
2.09" - Average rainfall in March:
2.4" - Average rainfall in April:
2.48" - Average rainfall in May:
1.97" - Average rainfall in June:
2.6"
- Average rainfall in July:
2.17" - Average rainfall in August:
2.09" - Average rainfall in September:
1.54" - Average rainfall in October:
2.83" - Average rainfall in November:
2.48" - Average rainfall in December:
2.8"
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
New Castle, NH
- Average rainfall days in January:
7.5 days - Average rainfall days in February:
7.8 days - Average rainfall days in March:
11.8 days - Average rainfall days in April:
13.8 days - Average rainfall days in May:
14.8 days - Average rainfall days in June:
15 days
- Average rainfall days in July:
14.1 days - Average rainfall days in August:
12.8 days - Average rainfall days in September:
11.3 days - Average rainfall days in October:
13.3 days - Average rainfall days in November:
10.5 days - Average rainfall days in December:
11.5 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
New Castle, NH
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
New Castle, NH
- Average snowfall days in January:
8.8 days - Average snowfall days in February:
8 days - Average snowfall days in March:
6.8 days - Average snowfall days in April:
1.4 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.3 days - Average snowfall days in November:
2.4 days - Average snowfall days in December:
7.5 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
New Castle, NH
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 / Average sunshine
New Castle, NH
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 18min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - Average daylight in December:
9h and 6min
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 January:
5h and 6min - Average sunshine in February:
4h and 48min - Average sunshine in March:
5h and 48min - Average sunshine in April:
8h and 6min - Average sunshine in May:
8h and 30min - Average sunshine in June:
9h and 12min
- Average sunshine in July:
10h and 18min - Average sunshine in August:
10h and 36min - Average sunshine in September:
8h and 36min - Average sunshine in October:
6h and 6min - Average sunshine in November:
5h and 30min - Average sunshine in December:
4h and 48min
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
New Castle, NH
- Average sunshine days in January:
15.9 days - Average sunshine days in February:
14.1 days - Average sunshine days in March:
13.9 days - Average sunshine days in April:
13.2 days - Average sunshine days in May:
14.8 days - Average sunshine days in June:
13.3 days
- Average sunshine days in July:
14.8 days - Average sunshine days in August:
15.5 days - Average sunshine days in September:
16.8 days - Average sunshine days in October:
15.1 days - Average sunshine days in November:
16.5 days - Average sunshine days in December:
14.5 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
New Castle, NH
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
New Castle, NH
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
New Castle, NH
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).
