Chesterfield weather in August

In August, Chesterfield sees average daytime highs of 86°F and overnight lows near 68°F, with 2.9 in of rain across 9 wet days and about 13.5 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 86°F through the month. The sky is clear or mostly clear about 42% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 hours at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Chesterfield's 2nd-clearest and 12th-windiest month. For the whole year in context, see Chesterfield's year-round climate.

Daytime high
86°
2nd warmest
Overnight low
68°
11th coldest
Rainfall
2.9 in
9 wet days
Daylight
13 h 30 min
5:21 AM – 6:52 PM
Cloud cover
50%
2nd clearest
Wind
5 mph
12th windiest
Solar energy
5.77 kWh/m²
Travel score
5.3
out of 10

Chesterfield is city in St. Louis County, Missouri, United States.

Density
551/km²
people per km²
Founded
1837

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 86°F through the month.

A typical August day in Chesterfield reaches about 86°F in the afternoon and slips back to 68°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 94°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18769
28769
38769
48769
58769
68769
78669
88669
98669
108668
118668
128668
138668
148668
158668
168668
178668
188668
198668
208667
218667
228667
238667
248667
258567
268567
278567
288566
298566
308566
318466

How August really feels in Chesterfield

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.

Chesterfield weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 24°2.6839.60.0
Feb44° / 28°2.47.82.810.50.8
Mar55° / 37°3.710.81.411.73.5
Apr66° / 47°4.511.40.2135.8
May75° / 58°4.913.4014.16.2
Jun84° / 67°4.011.2014.65.4
Jul87° / 70°3.39.8014.44.7
Aug86° / 68°2.99013.55.3
Sep79° / 60°3.27.6012.37.1
Oct67° / 48°3.48.40116.6
Nov54° / 37°3.68.70.89.93.5
Dec43° / 28°2.58.12.29.30.6

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 42% 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 38%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35842
45842
55842
65941
75941
85941
95941
106040
116139
126139
136139
146238
156238
166238
176337
186436
196436
206436
216436
226337
236337
246337
256436
266436
276436
286436
296535
306535
316535

Chance of precipitation in August

Any precipitation

Chesterfield gets around 2.9 in of rain over 9 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 29% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
131
231
331
431
530
630
730
830
930
1030
1130
1230
1330
1430
1530
1629
1729
1829
1929
2029
2129
2228
2328
2428
2527
2627
2727
2826
2926
3026
3126

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 33% of days. Sticky, muggy-or-worse air turns up on roughly 58% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
13132228321
23132229311
34132230301
44132231291
54132232291
64132232281
74132233271
85132133271
95132134261
105142034261
115142034261
125151934251
136151934251
146161934251
156161934251
166161934241
176161933241
186161933241
196162033241
206162033241
216162033240
226162033240
236162033240
246152133240
256152133240
267152233230
277152232230
288152332220
298152332210
309162331200
3110162431190

Wind in August

Winds average 5 mph in August, the calmest month.

Across August, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 hours at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 5:07 AM to 5:35 AM, and sunset from 7:09 PM to 6:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:077:09
214.05:087:08
314.05:097:07
413.95:107:06
513.95:117:05
613.95:127:04
713.85:137:03
813.85:147:02
913.85:147:01
1013.75:157:00
1113.75:166:58
1213.75:176:57
1313.65:186:56
1413.65:196:55
1513.65:206:53
1613.55:216:52
1713.55:226:51
1813.45:236:49
1913.45:246:48
2013.45:256:46
2113.35:256:45
2213.35:266:44
2313.25:276:42
2413.25:286:41
2513.25:296:39
2613.15:306:38
2713.15:316:36
2813.05:326:35
2913.05:336:33
3013.05:346:32
3112.95:356:30

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.77 kWh/m².

For context, solar energy here swings from a low near 1.91 kWh/m² to a high of 6.42 kWh/m² in June across the year — August's 5.77 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.1Intense
56.0Intense
66.0Intense
76.0Intense
86.0Bright
96.0Bright
105.9Bright
115.9Bright
125.9Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.6Bright
225.6Bright
235.6Bright
245.5Bright
255.5Bright
265.5Bright
275.4Bright
285.4Bright
295.4Bright
305.3Bright
315.3Bright
Planning a trip in August

Hazard calendar for Chesterfield

In seasonPeak

In August, Chesterfield sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Chesterfield sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Chesterfield?

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

5.3
Sightseeing
6th-best month of the year
7.2
Beach & pool
1st-best month of the year

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

What to pack for Chesterfield in August

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

In August, Chesterfield sees daytime highs around 86°F and nights near 68°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Chesterfield in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Chesterfield peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 23UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Chesterfield 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 Chesterfield is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1616 µg/m³Oct 237 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar11Good
Apr10Good
May13Moderate
Jun14Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov7Good
Dec8Good
Location & terrain

Where is Chesterfield?

Chesterfield sits at 38.7°N, 90.6°W, 472 ft above sea level, in United States. The nearest listed city is Ballwin, 5.0 mi away.

Topography around Chesterfield

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

Within 2 miles, the terrain around Chesterfield has only modest variations in elevation — a maximum elevation change of 246 ft around an average of 531 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 643 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,040 ft.

The land around Chesterfield is covered by trees (44%) and artificial surfaces (21%) within 2 miles, trees (58%) within 10 miles, and trees (54%) and cropland (29%) within 50 miles.

2 miles
246 ft
10 miles
643 ft
50 miles
1,040 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Ballwin 5.0 mi · Manchester 5.6 mi · Wildwood 7.5 mi · Creve Coeur 8.1 mi · Maryland Heights 8.7 mi · Saint Charles 9.9 mi · Saint Peters 9.9 mi · Kirkwood 11 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 Chesterfield (38.6631°, -90.5771°, elevation 472 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).