Climate and average weather in New Castle

In New Castle, the summers are warm, showery, and partly cloudy and the winters are very cold, snowy, and mostly cloudy.

Best: mid May to mid October

Over the course of the year, the temperature in New Castle typically varies from 21°F to 82°F, and is rarely below 1°F or above 90°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit New Castle for warm-weather activities is from mid May to mid October.

Hottest
Jul
82°
Coldest
Jan
21°
Wettest
Apr
4.7 in
Driest
Feb
2.6 in
Rain / yr
42.3 in
125 wet days
Daylight
9.2–14.8 h
shortest–longest
Elevation
1,063 ft
39.9°N
Clearest
Sep
50% cloud

New Castle is city in Indiana, United States.

Density
930/km²
people per km²
Founded
1822

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

New Castle weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid May to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in New Castle, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.6 months, from May 15 to September 30, with daily high temperatures above 70°F. The hottest month of the year in New Castle is July, with an average high of 82°F and low of 66°F.

The cool season lasts 3.0 months, from December 2 to March 2, with daily high temperatures below 44°F. The coldest month of the year in New Castle is January, with an average low of 21°F and high of 35°F.

Days typically run about 16°F warmer than nights, with the widest day–night swing (around 19°F) in September.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3521
Feb3824
Mar4932
Apr6243
May7153
Jun7963
Jul8266
Aug8164
Sep7656
Oct6345
Nov5035
Dec3926

How hot and cold New Castle really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about 9°F (around January 21), with roughly 151 freezing days a year (feels-like at or below 32°F) 53 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan35351021
Feb39381324
Mar49492432
Apr62623743
May71715353
Jun80796363
Jul83826666
Aug82816464
Sep76765756
Oct63634145
Nov50502735
Dec39391726

Average hourly temperature in New Castle

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 82°F, and coldest before dawn in January, near 21°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

New Castle weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan35° / 21°3.29.85.39.50.0
Feb38° / 24°2.68.84.610.40.0
Mar49° / 32°3.810.92.711.72.0
Apr62° / 43°4.712.50.7134.8
May71° / 53°4.613.6014.26.0
Jun79° / 63°4.212.2014.86.2
Jul82° / 66°3.411.4014.56.1
Aug81° / 64°3.09.8013.66.6
Sep76° / 56°2.97.9012.37.2
Oct63° / 45°3.28.80.210.95.7
Nov50° / 35°3.48.71.19.82.3
Dec39° / 26°3.210.33.99.20.1

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

New Castle gets about 42.3 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.7 months, from around Mar 16 to Aug 4, peaking in May at about 45% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Sep 11.

April is the wettest month by volume, with 4.7 in over about 13 wet days; February is the driest, with 2.6 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 4 · 45%Sep 11 · 26%
Rain on a day (%)Rain days
Jan3210
Feb319
Mar3511
Apr4213
May4314
Jun4112
Jul3711
Aug3110
Sep278
Oct289
Nov299
Dec3310

Monthly rainfall

Over a full year, New Castle collects about 42.3 in of rain across 125 wet days — roughly 3.5 in in an average month.

It doesn’t fall evenly. April is the wettest month with 4.7 in, while February is the driest at just 2.6 in. The three wettest months alone bring about 32% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec3.22.63.84.74.64.23.43.02.93.23.43.2
Rainfall (in)Rain daysSnow days
Jan3.2105
Feb2.695
Mar3.8113
Apr4.7131
May4.6140
Jun4.2120
Jul3.4110
Aug3.0100
Sep2.980
Oct3.290
Nov3.491
Dec3.2104

Snow in New Castle

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

New Castle averages about 18 snowy days a year. Snow season runs roughly Oct 31 to Apr 21 — about 5.7 months.

January is snowiest, with roughly 5 days of snow and an estimated 9 in of snowfall. Over the year that adds up to an estimated 35 in of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 17
Snow daysSnowfall (in)
Jan59
Feb59
Mar35
Apr11
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov12
Dec49

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In New Castle, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around June 5 and lasts for 4.8 months, ending around October 28. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 58% of the time on average.

The cloudier part of the year begins around October 29 and lasts for 7.2 months, ending around June 4. The cloudiest month is January, when it is overcast or mostly cloudy 72% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecSep 12 · 59%Jan 11 · 27%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2872
Feb3169
Mar3664
Apr3763
May3862
Jun4753
Jul5545
Aug5545
Sep5842
Oct4951
Nov3763
Dec2971

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 10, brings about 14 h 48 min of light; the shortest, around January 1, only 9 h 12 min — a swing of roughly 5 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.58:075:35
Feb10.47:436:09
Mar11.77:016:41
Apr13.06:107:13
May14.25:327:44
Jun14.85:178:06
Jul14.55:308:04
Aug13.65:587:33
Sep12.36:286:44
Oct10.96:595:54
Nov9.87:345:19
Dec9.28:025:13

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

New Castle averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 5 and 13 days.

The sunnier stretch runs 4.9 months, from around Jun 19 to Nov 14. The sunniest month is September, with roughly 13 sunny days (mixed).

The greyest month is February, down near 6 sunny days — about 53% fewer than the September peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedSep 1013 daysFeb 205 days
Sunny daysSky
Jan6Gloomy
Feb5Gloomy
Mar7Gloomy
Apr7Gloomy
May7Gloomy
Jun8Mixed
Jul10Mixed
Aug11Mixed
Sep13Mixed
Oct11Mixed
Nov8Mixed
Dec6Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In New Castle, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.3 months, from around May 15 to September 21. The muggiest month is July, when the air feels humid, muggy or worse about 71% of the time.

The most comfortable stretch runs from around September 22 to May 14, and January is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 1 · 100%Jul 19 · 26%oppressivemuggydryhumidcomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar982000
Apr926200
May63151660
Jun271823274
Jul1019233117
Aug1523252611
Sep492116132
Oct869420
Nov972000
Dec1000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in New Castle is typically light breeze, near 9 mph, and varies moderately with the seasons.

The windier part of the year lasts 7.1 months, from around Oct 12 to May 14. The windiest month is January, averaging about 10 mph (light breeze).

The calmer part of the year runs from around May 15 to Oct 11, with August the calmest month at about 6 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyJan 10 · 10 mphAug 6 · 6 mph
Wind speed (mph)Feels
Jan10light breeze
Feb10light breeze
Mar10light breeze
Apr10light breeze
May9light breeze
Jun7calm
Jul7calm
Aug6calm
Sep7calm
Oct9light breeze
Nov10light breeze
Dec10light breeze

Best time to visit New Castle

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in New Castle throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late May, New Castle is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit New Castle for general outdoor tourist activities is from mid May to mid October, with a peak score in the third week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 16 · 7.3

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.1poor
Mar2.0poor
Apr4.8fair
May6.0good
Jun6.2good
Jul6.1good
Aug6.6good
Sep7.2good
Oct5.7good
Nov2.3poor
Dec0.1poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit New Castle for hot-weather activities is from early June to late September, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 27 · 6.9

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for New Castle, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 82°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 35°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, New Castle sees daytime highs around 82°F and nights near 66°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

UV index (midday) in New Castle by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in New Castle peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 20UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Average hourly UV index in New Castle

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar4.50
Apr60
May7.54
Jun8.55.5
Jul8.55.5
Aug7.54
Sep60.5
Oct2.50
Nov00
Dec00

Air quality in New Castle by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in New Castle is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar12Good
Apr12Good
May14Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in New Castle typically lasts about 255 days, from around March 16 to November 25 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 19 to October 20.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 1650%Apr 1990%Oct 2090%Nov 2550%
Frost-free chance (%)Frost nights
Jan2031
Feb2328
Mar5131
Apr8616
May990
Jun1000
Jul1000
Aug1000
Sep1000
Oct928
Nov6130
Dec3131

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. New Castle banks about 3,155 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr81
May378
Jun632
Jul747
Aug698
Sep483
Oct136
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

New Castle receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.7 and 6.4 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 19 to Sep 25. The brightest month is July, averaging about 6.3 kWh/m² (intense).

The dimmest month is December, down near 1.7 kWh/m² — roughly 73% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.4 kWhDec 151.7 kWh
Solar energy (kWh/m²)Level
Jan2.0Moderate
Feb3.0Moderate
Mar4.0Bright
Apr5.1Bright
May5.7Bright
Jun6.3Intense
Jul6.3Intense
Aug5.6Bright
Sep4.5Bright
Oct3.2Moderate
Nov2.2Moderate
Dec1.7Dim

Where is New Castle?

New Castle sits at 39.9°N, 85.4°W, 1,063 ft above sea level, in United States. The nearest listed city is Muncie, 18 mi away.

Topography around New Castle

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of New Castle.

Within 2 miles, the terrain around New Castle has only modest variations in elevation — a maximum elevation change of 187 ft around an average of 1,050 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 338 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 860 ft.

The land around New Castle is covered by trees (38%), cropland (22%) and grassland (21%) within 2 miles, cropland (68%) within 10 miles, and cropland (69%) and trees (20%) within 50 miles.

2 miles
187 ft
10 miles
338 ft
50 miles
860 ft
treesgrasslandcroplandartificial surfaceswater
Nearby: Muncie 18 mi · Anderson 21 mi · Greenfield 24 mi · Richmond 26 mi · Fishers 34 mi · Noblesville 35 mi · Lawrence 35 mi · Shelbyville 35 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for New Castle (39.9289°, -85.3702°, elevation 1,063 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).