New Castle weather in August

In August, New Castle sees average daytime highs of 81°F and overnight lows near 64°F, with 3.0 in of rain across 9.8 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 81°F through the month. The sky is clear or mostly clear about 36% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 06 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is New Castle's 2nd-clearest and 12th-windiest month. For the whole year in context, see New Castle's year-round climate.

Daytime high
81°
2nd warmest
Overnight low
64°
11th coldest
Rainfall
3.0 in
9.8 wet days
Daylight
13 h 36 min
5:58 AM – 7:33 PM
Cloud cover
54%
2nd clearest
Wind
6 mph
12th windiest
Solar energy
5.63 kWh/m²
Travel score
6.6
out of 10

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.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 81°F through the month.

A typical August day in New Castle reaches about 81°F in the afternoon and slips back to 64°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 74°F and 88°F. Set against its neighbours, August runs on par with July and about 6°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18265
28265
38265
48265
58265
68265
78265
88165
98165
108164
118164
128164
138164
148164
158164
168164
178164
188164
198164
208164
218164
228164
238164
248164
258163
268163
278163
288163
298063
308062
318062

How August really feels in New Castle

Once humidity and wind are folded in, August averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

New Castle weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 10th-wettest month here — the current month is highlighted below.

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

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25545
35644
45644
55644
65644
75545
85545
95545
105446
115446
125347
135446
145347
155446
165446
175545
185545
195545
205545
215545
225545
235446
245545
255545
265545
275545
285644
295644
305644
315644

Chance of precipitation in August

Any precipitation

New Castle gets around 3.0 in of rain over 9.8 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 35% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
135
234
334
434
534
634
734
833
933
1033
1133
1233
1333
1432
1532
1632
1731
1831
1930
2030
2130
2230
2330
2429
2529
2629
2729
2828
2928
3028
3128

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the muggy band about 26% of days. Sticky, muggy-or-worse air turns up on roughly 37% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1923262417
21023272416
31023272416
41123272415
51122272415
61222272415
71222272414
81322272414
91322272414
101422262413
111423262413
121423262413
131423252512
141423252512
151424252511
161424252611
171424252610
181424252710
191424252710
20142425289
21142425289
22142425289
23152325289
24152325289
25162225289
26172225288
27182125278
28202124278
29212124268
30222124267
31232124257

Wind in August

Winds average 6 mph in August, the calmest month.

Across August, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 5:44 AM to 6:13 AM, and sunset from 7:52 PM to 7:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:447:52
214.15:447:50
314.15:457:49
414.05:467:48
514.05:477:47
614.05:487:46
713.95:497:45
813.95:507:44
913.95:517:42
1013.85:527:41
1113.85:537:40
1213.75:547:39
1313.75:557:37
1413.75:567:36
1513.65:577:35
1613.65:587:33
1713.55:597:32
1813.56:007:30
1913.56:017:29
2013.46:027:28
2113.46:037:26
2213.36:047:25
2313.36:057:23
2413.36:067:22
2513.26:077:20
2613.26:087:18
2713.16:097:17
2813.16:107:15
2913.16:117:14
3013.06:127:12
3113.06:137:11

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.63 kWh/m².

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 6.27 kWh/m² in July across the year — August's 5.63 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.0Intense
26.0Bright
36.0Bright
45.9Bright
55.9Bright
65.9Bright
75.9Bright
85.8Bright
95.8Bright
105.8Bright
115.8Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.6Bright
175.6Bright
185.6Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.4Bright
245.4Bright
255.3Bright
265.3Bright
275.3Bright
285.2Bright
295.2Bright
305.2Bright
315.1Bright
Planning a trip in August

Is August a good time to visit New Castle?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.6
Sightseeing
2nd-best month of the year
6.8
Beach & pool
1st-best month of the year

August is a reasonable time to visit New Castle for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for New Castle in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, New Castle sees daytime highs around 81°F and nights near 64°F. Pack light clothes. Worth having: rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in New Castle in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

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

Air quality in New Castle in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual 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
Location & terrain

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
August weather 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).