Wentzville weather in May

In May, Wentzville sees average daytime highs of 75°F and overnight lows near 57°F, with 4.9 in of rain across 13.3 wet days and about 14.1 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 71°F in the first days to 79°F by the end. The sky is clear or mostly clear about 29% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of May to 14 h 30 min by month's end. Set against the rest of the year, May is Wentzville's 8th-clearest and 8th-windiest month. For the whole year in context, see Wentzville's year-round climate.

Daytime high
75°
5th warmest
Overnight low
57°
8th coldest
Rainfall
4.9 in
13.3 wet days
Daylight
14 h 06 min
4:56 AM – 7:03 PM
Cloud cover
62%
8th clearest
Wind
7 mph
8th windiest
Solar energy
5.79 kWh/m²
Travel score
6.3
out of 10

Wentzville is city in St. Charles County, Missouri, United States.

Density
683/km²
people per km²
Founded
1855

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 71°F in the first days to 79°F by the end.

A typical May day in Wentzville reaches about 75°F in the afternoon and slips back to 57°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 86°F. Set against its neighbours, May runs about 9°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17052
27152
37153
47153
57254
67254
77254
87355
97355
107355
117456
127456
137456
147456
157557
167557
177558
187658
197658
207658
217659
227759
237760
247760
257860
267861
277861
287961
297962
307962
318062

How May really feels in Wentzville

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.

Wentzville 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
Jan40° / 24°2.57.739.60.0
Feb44° / 28°2.47.62.910.50.8
Mar55° / 37°3.610.61.411.73.5
Apr66° / 47°4.511.30.2135.8
May75° / 57°4.913.3014.16.3
Jun84° / 66°4.011.1014.75.5
Jul87° / 70°3.29.9014.44.6
Aug86° / 67°3.09.2013.55.2
Sep79° / 59°3.27.6012.37.1
Oct67° / 48°3.38.50116.6
Nov54° / 37°3.58.30.89.93.5
Dec43° / 28°2.47.72.29.30.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24159
34258
44258
54258
64258
74258
84258
94258
104357
114357
124357
134357
144357
154357
164357
174456
184456
194357
204456
214357
224456
234357
244258
254456
264357
274456
284357
294357
304456
314456

Chance of precipitation in May

Any precipitation

Wentzville gets around 4.9 in of rain over 13.3 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 43% and peaks near 45% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
145
245
345
444
544
644
743
843
942
1042
1142
1241
1341
1441
1541
1641
1742
1842
1942
2043
2143
2243
2343
2443
2543
2643
2742
2842
2942
3041
3141

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 48% of days. Sticky, muggy-or-worse air turns up on roughly 17% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
170181020
267191130
366191230
463201340
562201440
660201550
758201660
857191770
956191780
1055181890
1154181990
12541719100
13521720110
14521620120
15501520141
16491520151
17481421161
18471421171
19461421191
20441421201
21421421221
22411421232
23391421242
24371421252
25361521262
26341621263
27321621273
28311721283
29291821294
30281821294
31261921304

Wind in May

Winds average 7 mph in May.

Across May, 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
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 min at the start of May to 14 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 5:13 AM to 4:46 AM, and sunset from 6:49 PM to 7:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:136:49
213.65:116:50
313.75:106:51
413.75:096:52
513.75:086:53
613.85:076:53
713.85:056:54
813.95:046:55
913.95:036:56
1013.95:026:57
1114.05:016:58
1214.05:006:59
1314.04:597:00
1414.04:587:01
1514.14:577:02
1614.14:567:03
1714.14:557:04
1814.24:557:05
1914.24:547:06
2014.24:537:07
2114.34:527:07
2214.34:517:08
2314.34:517:09
2414.34:507:10
2514.44:497:11
2614.44:497:12
2714.44:487:12
2814.44:487:13
2914.44:477:14
3014.54:477:15
3114.54:467:15

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.79 kWh/m².

For context, solar energy here swings from a low near 1.92 kWh/m² to a high of 6.42 kWh/m² in June across the year — May's 5.79 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.4Bright
35.4Bright
45.4Bright
55.5Bright
65.5Bright
75.5Bright
85.6Bright
95.6Bright
105.7Bright
115.7Bright
125.7Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.9Bright
185.9Bright
195.9Bright
205.9Bright
215.9Bright
226.0Bright
236.0Bright
246.0Bright
256.0Bright
266.0Intense
276.0Intense
286.0Intense
296.0Intense
306.0Intense
316.1Intense
Planning a trip in May

Is May a good time to visit Wentzville?

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

6.3
Sightseeing
3rd-best month of the year
5.2
Beach & pool
5th-best month of the year

May is a reasonable time to visit Wentzville for sightseeing.

What to pack for Wentzville in May

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

In May, Wentzville sees daytime highs around 75°F and nights near 57°F. Worth packing: light clothes, rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

UV index in Wentzville in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May 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 Wentzville peaks around June 22 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 highHighModerateJun 22UV 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 Wentzville in May

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Wentzville 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 Wentzville?

Wentzville sits at 38.8°N, 90.9°W, 623 ft above sea level, in United States. The nearest listed city is O'Fallon, 8.1 mi away.

Topography around Wentzville

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

Within 2 miles, the terrain around Wentzville has only modest variations in elevation — a maximum elevation change of 184 ft around an average of 610 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 541 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 984 ft.

The land around Wentzville is covered by artificial surfaces (34%), trees (33%) and grassland (25%) within 2 miles, trees (46%), grassland (23%) and cropland (21%) within 10 miles, and trees (54%) and cropland (28%) within 50 miles.

2 miles
184 ft
10 miles
541 ft
50 miles
984 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: O'Fallon 8.1 mi · Saint Peters 12 mi · Chesterfield 18 mi · Wildwood 19 mi · Saint Charles 20 mi · Ballwin 22 mi · Manchester 24 mi · Maryland Heights 24 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 Wentzville (38.8114°, -90.8529°, elevation 623 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).