Duncan weather in May

In May, Duncan sees average daytime highs of 81°F and overnight lows near 62°F, with 4.7 in of rain across 10.6 wet days and about 13.8 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 77°F in the first days to 85°F by the end. The sky is clear or mostly clear about 40% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of May to 14 h 06 min by month's end. Set against the rest of the year, May is Duncan's 12th-clearest and 3rd-windiest month. For the whole year in context, see Duncan's year-round climate.

Daytime high
81°
5th warmest
Overnight low
62°
8th coldest
Rainfall
4.7 in
10.6 wet days
Daylight
13 h 48 min
5:34 AM – 7:22 PM
Cloud cover
51%
12th clearest
Wind
9 mph
3rd windiest
Solar energy
6.08 kWh/m²
Travel score
6.3
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 May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 77°F in the first days to 85°F by the end.

A typical May day in Duncan reaches about 81°F in the afternoon and slips back to 62°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 71°F and 90°F. Set against its neighbours, May runs about 8°F warmer than April and about 8°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17656
27756
37757
47757
57857
67858
77858
87859
97959
107959
117960
128060
138060
148061
158161
168162
178162
188262
198263
208263
218264
228364
238364
248364
258365
268465
278465
288466
298566
308566
318567

How May really feels in Duncan

Once humidity and wind are folded in, May 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

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

Duncan weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in May, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 43%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35743
45743
55644
65743
75644
85644
95644
105743
115743
125743
135743
145743
155743
165743
175743
185743
195743
205743
215743
225743
235743
245743
255743
265842
275842
285842
295743
305743
315842

Chance of precipitation in May

Any precipitation

Duncan gets around 4.7 in of rain over 10.6 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
131
231
332
432
532
633
733
833
933
1033
1133
1233
1333
1433
1534
1634
1734
1834
1934
2035
2135
2235
2335
2435
2535
2635
2735
2835
2935
3034
3134

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 31% of days. Sticky, muggy-or-worse air turns up on roughly 23% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
158171960
256172070
353182180
451182290
5491824100
6471825100
7451826110
8431827120
9411828130
10401829140
11381829150
12371830160
13351730170
14341731180
15321731190
16311731201
17291731221
18281731231
19261632251
20241632271
21221632281
22211632301
23191732312
24171732332
25161732342
26141731362
27131731372
28111631383
29101631403
30101630413
3191629424

Wind in May

Winds average 9 mph in May.

Across May, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
110light breeze
210light breeze
310light breeze
410light breeze
510light breeze
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
279light breeze
289light breeze
299light breeze
309light breeze
319light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 24 min at the start of May to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over May. Sunrise moves from 5:48 AM to 5:26 AM, and sunset from 7:10 PM to 7:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:487:10
213.45:477:11
313.45:467:12
413.55:457:12
513.55:447:13
613.55:437:14
713.55:427:15
813.65:417:16
913.65:407:16
1013.65:397:17
1113.75:387:18
1213.75:377:19
1313.75:377:20
1413.75:367:20
1513.85:357:21
1613.85:347:22
1713.85:337:23
1813.85:337:24
1913.95:327:24
2013.95:317:25
2113.95:317:26
2213.95:307:27
2314.05:307:27
2414.05:297:28
2514.05:287:29
2614.05:287:29
2714.05:277:30
2814.15:277:31
2914.15:277:31
3014.15:267:32
3114.15:267:33

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.08 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 — May's 6.08 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.0Bright
26.0Bright
36.0Bright
46.0Bright
56.0Intense
66.0Intense
76.0Intense
86.0Intense
96.0Intense
106.0Intense
116.1Intense
126.1Intense
136.1Intense
146.1Intense
156.1Intense
166.1Intense
176.1Intense
186.1Intense
196.2Intense
206.2Intense
216.2Intense
226.2Intense
236.2Intense
246.2Intense
256.2Intense
266.2Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
316.4Intense
Planning a trip in May

Is May a good time to visit Duncan?

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

6.3
Sightseeing
4th-best month of the year
6.7
Beach & pool
4th-best month of the year

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

What to pack for Duncan in May

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

In May, Duncan sees daytime highs around 81°F and nights near 62°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

light clothessun protectionrain gear

UV index in Duncan in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 9 (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
May 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).