Cary weather in May

In May, Cary sees average daytime highs of 68°F and overnight lows near 50°F, with 4.3 in of rain across 12.2 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 63°F in the first days to 72°F by the end. The sky is clear or mostly clear about 26% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 48 min at the start of May to 14 h 48 min by month's end. Set against the rest of the year, May is Cary's 6th-clearest and 8th-windiest month. For the whole year in context, see Cary's year-round climate.

Daytime high
68°
5th warmest
Overnight low
50°
8th coldest
Rainfall
4.3 in
12.2 wet days
Daylight
14 h 24 min
4:38 AM – 7:01 PM
Cloud cover
64%
6th clearest
Wind
8 mph
8th windiest
Solar energy
5.74 kWh/m²
Travel score
5.9
out of 10

Cary is village in Illinois, United States.

Founded
1833

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 63°F in the first days to 72°F by the end.

A typical May day in Cary reaches about 68°F in the afternoon and slips back to 50°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 55°F and 82°F. Set against its neighbours, May runs about 11°F warmer than April and about 10°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16245
26345
36346
46446
56446
66447
76547
86547
96548
106648
116648
126649
136749
146749
156750
166850
176850
186951
196951
206951
217052
227052
237053
247153
257153
267154
277254
287254
297255
307355
317355

How May really feels in Cary

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.

Cary 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
Jan30° / 17°2.07.969.30.0
Feb34° / 20°1.975.210.30.0
Mar45° / 29°2.59.73.311.61.1
Apr57° / 39°4.312.31.113.13.7
May68° / 50°4.312.2014.45.9
Jun78° / 61°3.811.80156.4
Jul82° / 65°3.410.4014.86.4
Aug80° / 63°3.610.6013.76.6
Sep73° / 55°3.08.8012.37.0
Oct60° / 44°3.08.70.210.85.0
Nov46° / 33°2.47.81.69.61.4
Dec35° / 22°2.184.690.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% 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 60%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23565
33466
43466
53466
63565
73664
83664
93664
103862
113862
123862
133961
144060
154060
164159
174258
184357
194357
204357
214357
224357
234357
244357
254456
264456
274357
284357
294357
304357
314357

Chance of precipitation in May

Any precipitation

Cary gets around 4.3 in of rain over 12.2 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 40% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
141
241
341
442
541
641
741
841
941
1040
1140
1240
1339
1439
1539
1639
1739
1838
1938
2038
2138
2239
2339
2439
2540
2640
2740
2841
2941
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 78% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
192710
291711
389821
489821
588831
687931
787931
886941
9841042
10831052
11831052
12831052
13821062
14811162
15791173
16791173
17791173
18771184
19771184
20741295
217312105
227312105
237013116
247013116
256813127
266714127
276614137
286415138
296315148
306216148
316017158

Wind in May

Winds average 8 mph in May.

Across May, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
317light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 48 min at the start of May to 14 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 4:56 AM to 4:26 AM, and sunset from 6:44 PM to 7:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:566:44
213.94:546:46
313.94:536:47
413.94:526:48
514.04:506:49
614.04:496:50
714.14:486:51
814.14:476:52
914.14:456:53
1014.24:446:54
1114.24:436:56
1214.24:426:57
1314.34:416:58
1414.34:406:59
1514.44:397:00
1614.44:387:01
1714.44:377:02
1814.54:367:03
1914.54:357:04
2014.54:347:05
2114.64:337:06
2214.64:327:07
2314.64:317:08
2414.64:307:09
2514.74:307:10
2614.74:297:11
2714.74:287:12
2814.74:277:12
2914.84:277:13
3014.84:267:14
3114.84:267:15

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.74 kWh/m².

For context, solar energy here swings from a low near 1.6 kWh/m² to a high of 6.32 kWh/m² in June across the year — May's 5.74 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.4Bright
45.4Bright
55.4Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.6Bright
115.6Bright
125.6Bright
135.7Bright
145.7Bright
155.7Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
246.0Bright
256.0Bright
266.0Bright
276.0Intense
286.0Intense
296.0Intense
306.0Intense
316.1Intense
Planning a trip in May

Is May a good time to visit Cary?

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

5.9
Sightseeing
5th-best month of the year
3.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Cary for sightseeing.

What to pack for Cary in May

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

In May, Cary sees daytime highs around 68°F and nights near 50°F. Worth packing: rain gear and sun protection. About 12 days see rain.

rain gearsun protection

Sea temperature near Cary in May

The nearest coast averages about 43°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 22 mi away) is warmest in August at about 71°F and coldest in March near 36°F.

It's comfortable for a long swim from Jul 18 to Sep 8 — about 1.7 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr38Bracing
May43Bracing
Jun55Bracing
Jul68Refreshing
Aug71Refreshing
Sep67Cool
Oct57Bracing
Nov47Bracing
Dec42Bracing

UV index in Cary 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 Cary peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 21UV 9Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Cary 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 Cary 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 Cary?

Cary sits at 42.2°N, 88.2°W, 823 ft above sea level, in United States. The nearest listed city is Algonquin, 4.3 mi away.

Topography around Cary

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

Within 2 miles, the terrain around Cary has only modest variations in elevation — a maximum elevation change of 213 ft around an average of 827 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 322 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 787 ft.

The land around Cary is covered by trees (54%) and grassland (25%) within 2 miles, trees (43%) and grassland (28%) within 10 miles, and cropland (35%), trees (20%) and water (20%) within 50 miles.

2 miles
213 ft
10 miles
322 ft
50 miles
787 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Algonquin 4.3 mi · Crystal Lake 4.3 mi · Lake in the Hills 5.0 mi · Carpentersville 6.2 mi · Lake Zurich 7.5 mi · McHenry 8.7 mi · Huntley 9.9 mi · Round Lake 12 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 Cary (42.212°, -88.2381°, elevation 823 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).