Plainfield weather in August

In August, Plainfield sees average daytime highs of 81°F and overnight lows near 63°F, with 3.6 in of rain across 10.5 wet days and about 13.7 hours of daylight. It is the 2nd-warmest and 5th-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 humid.

Daylight stretches from about 14 h 18 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Plainfield's 2nd-clearest and 12th-windiest month. For the whole year in context, see Plainfield's year-round climate.

Daytime high
81°
2nd warmest
Overnight low
63°
11th coldest
Rainfall
3.6 in
10.5 wet days
Daylight
13 h 42 min
5:06 AM – 6:48 PM
Cloud cover
55%
2nd clearest
Wind
6 mph
12th windiest
Solar energy
5.42 kWh/m²
Travel score
6.5
out of 10

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 Plainfield reaches about 81°F in the afternoon and slips back to 63°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 73°F and 88°F. Set against its neighbours, August runs about 2°F cooler than July and about 6°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18264
28264
38264
48264
58264
68264
78164
88164
98164
108164
118163
128163
138163
148163
158163
168163
178163
188063
198063
208063
218063
228063
238062
248062
258062
268062
278062
288062
298061
308061
317961

How August really feels in Plainfield

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.

Plainfield weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan31° / 17°2.18.15.99.30.0
Feb35° / 20°2.074.610.30.0
Mar47° / 30°2.79.62.911.71.5
Apr59° / 40°4.411.80.913.14.3
May70° / 51°4.612.7014.36.0
Jun79° / 61°4.311.80156.3
Jul83° / 65°3.711.2014.75.9
Aug81° / 63°3.610.5013.76.5
Sep74° / 55°3.08.3012.37.1
Oct62° / 43°3.19.10.110.95.3
Nov47° / 33°2.58.21.29.71.7
Dec36° / 23°2.284.390.0

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 20% of August, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15545
25545
35644
45644
55545
65545
75545
85545
95545
105545
115545
125545
135545
145545
155545
165545
175545
185644
195545
205545
215446
225545
235545
245545
255644
265644
275743
285743
295842
305941
315941

Chance of precipitation in August

Any precipitation

Plainfield gets around 3.6 in of rain over 10.5 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 33% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
234
333
433
533
633
733
833
933
1033
1133
1233
1334
1434
1534
1634
1734
1835
1935
2035
2135
2234
2334
2434
2533
2632
2732
2831
2931
3030
3130

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid 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 (%)Miserable (%)
110242428131
210242527131
310242527131
410242526131
510242625131
611242625141
711242624141
811242724131
912242724130
1012242723130
1112242723130
1213242723130
1313242723130
1413242723120
1513242723120
1613242724120
1713242724120
1813232725120
1913232725110
2013232626110
2113232626110
2213232627110
2313242527110
2413242527110
2514242526110
2614252426110
2715252426100
2816252425100
2917262424100
301826242490
311926232390

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 6 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
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 18 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 78 minutes over August. Sunrise moves from 4:51 AM to 5:22 AM, and sunset from 7:07 PM to 6:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.34:517:07
214.24:527:06
314.24:537:05
414.24:547:04
514.14:557:02
614.14:567:01
714.04:577:00
814.04:586:59
914.04:596:57
1013.95:006:56
1113.95:016:55
1213.95:026:53
1313.85:036:52
1413.85:046:50
1513.75:056:49
1613.75:066:48
1713.65:076:46
1813.65:086:45
1913.65:096:43
2013.55:106:42
2113.55:126:40
2213.45:136:38
2313.45:146:37
2413.35:156:35
2513.35:166:34
2613.35:176:32
2713.25:186:30
2813.25:196:29
2913.15:206:27
3013.15:216:25
3113.05:226:24

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.42 kWh/m².

For context, solar energy here swings from a low near 1.65 kWh/m² to a high of 6.3 kWh/m² in June across the year — August's 5.42 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.8Bright
45.8Bright
55.8Bright
65.7Bright
75.7Bright
85.7Bright
95.6Bright
105.6Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.4Bright
165.4Bright
175.4Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.2Bright
235.2Bright
245.2Bright
255.2Bright
265.1Bright
275.1Bright
285.1Bright
295.1Bright
305.0Bright
315.0Bright
Planning a trip in August

Is August a good time to visit Plainfield?

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

6.5
Sightseeing
2nd-best month of the year
6.7
Beach & pool
2nd-best month of the year

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

What to pack for Plainfield in August

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

In August, Plainfield sees daytime highs around 81°F and nights near 63°F. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Plainfield in August

The nearest coast averages about 73°F in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 34 mi away) is warmest in August at about 73°F and coldest in February near 36°F.

It's comfortable for a long swim from Jul 13 to Sep 15 — about 2.1 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr39Bracing
May45Bracing
Jun57Bracing
Jul70Refreshing
Aug73Refreshing
Sep68Refreshing
Oct58Bracing
Nov49Bracing
Dec42Bracing

UV index in Plainfield 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 Plainfield peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highHighModerateLowJun 20UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Plainfield 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 Plainfield is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 1817 µg/m³Oct 229 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar16Moderate
Apr14Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct9Good
Nov10Good
Dec11Good
Location & terrain

Where is Plainfield?

Plainfield sits at 41.6°N, 88.2°W, 617 ft above sea level, in United States. The nearest listed city is Romeoville, 6.2 mi away.

Topography around Plainfield

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

Within 2 miles, the terrain around Plainfield has only modest variations in elevation — a maximum elevation change of 174 ft around an average of 620 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 413 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 751 ft.

The land around Plainfield is covered by trees (24%), grassland (23%) and artificial surfaces (23%) within 2 miles, cropland (27%), grassland (24%) and artificial surfaces (24%) within 10 miles, and cropland (50%) within 50 miles.

2 miles
174 ft
10 miles
413 ft
50 miles
751 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Romeoville 6.2 mi · Crest Hill 7.5 mi · Shorewood 7.5 mi · Lockport 8.1 mi · Oswego 8.7 mi · Bolingbrook 8.7 mi · Joliet 9.3 mi · Montgomery 9.9 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 Plainfield (41.627°, -88.204°, elevation 617 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).