Duncan weather in August

In August, Duncan sees average daytime highs of 93°F and overnight lows near 73°F, with 1.9 in of rain across 5.6 wet days and about 13.3 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 95°F in the first days to 92°F by the end. The sky is clear or mostly clear about 58% of the time in August, and the air most often feels muggy.

Daylight stretches from about 13 h 42 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Duncan's 4th-clearest and 12th-windiest month. For the whole year in context, see Duncan's year-round climate.

Daytime high
93°
2nd warmest
Overnight low
73°
11th coldest
Rainfall
1.9 in
5.6 wet days
Daylight
13 h 18 min
5:57 AM – 7:15 PM
Cloud cover
39%
4th clearest
Wind
7 mph
12th windiest
Solar energy
6.35 kWh/m²
Travel score
3.4
out of 10

Duncan is city and county seat of Stephens County, Oklahoma, United States.

Density
188/km²
people per km²
Founded
1892

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 95°F in the first days to 92°F by the end.

A typical August day in Duncan reaches about 93°F in the afternoon and slips back to 73°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 85°F and 101°F. Set against its neighbours, August runs on par with July and about 8°F warmer than September.

60°70°80°90°100°151015202531
Avg high (°F)Avg low (°F)
19574
29574
39574
49574
59574
69474
79474
89474
99474
109474
119474
129474
139474
149473
159473
169473
179373
189373
199373
209373
219373
229373
239373
249372
259272
269272
279272
289272
299271
309171
319171

How August really feels in Duncan

Once humidity and wind are folded in, August averages 31 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
31
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Duncan 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
Jan52° / 32°1.54.80.9103.2
Feb56° / 36°1.85.80.910.74.4
Mar65° / 44°3.17.60.411.76.4
Apr73° / 52°3.67.9012.87.3
May81° / 62°4.710.6013.86.3
Jun89° / 70°3.68.6014.34.4
Jul94° / 74°1.85.8014.13.2
Aug93° / 73°1.95.6013.33.4
Sep85° / 65°2.86.4012.25.8
Oct74° / 54°3.56.8011.17.6
Nov62° / 42°2.15.50.210.26.2
Dec53° / 34°2.05.20.89.73.5

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 58% 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 23%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17624
27624
37624
47624
57624
67624
77624
87624
97624
107624
117624
127624
137624
147624
157624
167723
177723
187723
197723
207822
217822
227822
237822
247921
257921
267921
277822
287822
297822
307723
317723

Chance of precipitation in August

Any precipitation

Duncan gets around 1.9 in of rain over 5.6 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 19% and peaks near 20% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
117
218
318
418
518
618
719
819
919
1020
1120
1220
1320
1420
1520
1620
1720
1820
1919
2019
2119
2218
2318
2418
2518
2618
2718
2818
2918
3018
3119

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 43% of days. Sticky, muggy-or-worse air turns up on roughly 55% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
109304812
209314812
308314912
418314912
518314812
618314812
718314812
818314712
918314713
1028324613
1128324613
1228324513
1329324414
1439324314
1539324214
16310324214
17310324114
18311324014
19311324014
20312324013
21312324013
22313324012
23314314012
24314314011
25315314110
26416304010
2741630419
2841630419
2951630408
3061730408
3171729398

Wind in August

Winds average 7 mph in August, the calmest month.

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

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 42 min at the start of August to 12 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 54 minutes over August. Sunrise moves from 5:46 AM to 6:08 AM, and sunset from 7:30 PM to 6:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:467:30
213.75:467:29
313.75:477:28
413.75:487:28
513.65:497:27
613.65:497:26
713.65:507:25
813.55:517:24
913.55:527:23
1013.55:527:22
1113.55:537:21
1213.45:547:20
1313.45:557:18
1413.45:557:17
1513.35:567:16
1613.35:577:15
1713.35:587:14
1813.25:587:13
1913.25:597:11
2013.26:007:10
2113.16:017:09
2213.16:017:08
2313.16:027:06
2413.06:037:05
2513.06:047:04
2613.06:047:02
2712.96:057:01
2812.96:067:00
2912.96:076:58
3012.86:076:57
3112.86:086:56

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 6.35 kWh/m².

For context, solar energy here swings from a low near 2.59 kWh/m² to a high of 6.94 kWh/m² in July across the year — August's 6.35 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.7Intense
26.7Intense
36.7Intense
46.6Intense
56.6Intense
66.6Intense
76.5Intense
86.5Intense
96.5Intense
106.5Intense
116.4Intense
126.4Intense
136.4Intense
146.4Intense
156.3Intense
166.3Intense
176.3Intense
186.3Intense
196.3Intense
206.2Intense
216.2Intense
226.2Intense
236.2Intense
246.1Intense
256.1Intense
266.0Intense
276.0Intense
286.0Bright
295.9Bright
305.9Bright
315.8Bright
Planning a trip in August

Is August a good time to visit Duncan?

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

3.4
Sightseeing
10th-best month of the year
6.7
Beach & pool
3rd-best month of the year

August is a weaker month for outdoor sightseeing in Duncan. The water and warmth also suit a beach or pool day.

What to pack for Duncan in August

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

In August, Duncan sees daytime highs around 93°F and nights near 73°F. Pack light clothes and sun protection. About 6 days see rain.

light clothessun protection

UV index in Duncan in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Duncan peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr9Very high
May9Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep7Very high
Oct6High
Nov4Moderate
Dec3Moderate
Location & terrain

Where is Duncan?

Duncan sits at 34.5°N, 98.0°W, 1,122 ft above sea level, in United States. The nearest listed city is Lawton, 25 mi away.

Topography around Duncan

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

Within 2 miles, the terrain around Duncan has only modest variations in elevation — a maximum elevation change of 167 ft around an average of 1,125 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 367 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,716 ft.

The land around Duncan is covered by grassland (39%), trees (29%) and artificial surfaces (27%) within 2 miles, grassland (64%) and trees (25%) within 10 miles, and grassland (66%) within 50 miles.

2 miles
167 ft
10 miles
367 ft
50 miles
1,716 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Lawton 25 mi · Chickasha 38 mi · Wichita Falls 51 mi · Ardmore 52 mi · Norman 58 mi · Mustang 62 mi · Moore 64 mi · Yukon 70 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 Duncan (34.5023°, -97.9578°, elevation 1,122 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).