Northbrook weather in May

In May, Northbrook sees average daytime highs of 58°F and overnight lows near 50°F, with 4.1 in of rain across 11.7 wet days and about 14.4 hours of daylight. It is the 6th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 52°F in the first days to 64°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 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 Northbrook's 6th-clearest and 9th-windiest month. For the whole year in context, see Northbrook's year-round climate.

Daytime high
58°
6th warmest
Overnight low
50°
7th coldest
Rainfall
4.1 in
11.7 wet days
Daylight
14 h 24 min
4:36 AM – 6:59 PM
Cloud cover
62%
6th clearest
Wind
12 mph
9th windiest
Solar energy
5.9 kWh/m²
Travel score
4.1
out of 10

Northbrook is village in Illinois, United States.

Density
977/km²
people per km²
Founded
1901

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 52°F in the first days to 64°F by the end.

A typical May day in Northbrook reaches about 58°F in the afternoon and slips back to 50°F overnight — a 7°F spread between the day's warmth and the night's chill. On most days the high lands between 48°F and 68°F. Set against its neighbours, May runs about 12°F warmer than April and about 13°F cooler than June.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
15144
25245
35245
45345
55346
65346
75447
85447
95547
105548
115648
125649
135649
145749
155750
165850
175851
185951
195951
206052
216052
226053
236153
246154
256254
266255
276355
286356
296456
306457
316557

How May really feels in Northbrook

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.

Northbrook weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan30° / 21°2.99.879.30.0
Feb31° / 21°2.47.75.110.30.0
Mar37° / 29°3.09.83.211.60.0
Apr46° / 39°4.8121.413.11.3
May58° / 50°4.111.7014.44.1
Jun71° / 64°3.510.50156.5
Jul78° / 70°3.110.5014.86.8
Aug77° / 70°3.810.7013.77.0
Sep71° / 63°3.39.5012.36.8
Oct58° / 51°4.010.50.110.84.4
Nov46° / 39°3.4101.39.61.2
Dec36° / 28°3.1104.990.0

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 15% of May, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23961
33961
43961
54060
64060
74060
84060
94159
104159
114159
124357
134357
144357
154456
164555
174654
184654
194654
204555
214555
224555
234654
244753
254654
264555
274555
284654
294654
304654
314654

Chance of precipitation in May

Any precipitation

Northbrook gets around 4.1 in of rain over 11.7 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 38% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
138
238
339
439
539
639
739
839
938
1038
1138
1238
1338
1438
1538
1638
1737
1837
1937
2037
2137
2237
2337
2437
2537
2637
2737
2837
2937
3037
3137

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 82% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1982000
2972100
3963100
4963100
5954100
6945100
7945100
8926200
9926200
10917200
11908200
12908200
13889300
148610310
158610310
168511310
178312410
188212420
198113420
207914520
217714630
227515631
237315741
247116841
256916951
2667171051
2766171061
2864181161
2962181271
3060191371
3158191481

Wind in May

Winds average 12 mph in May.

Across May, daily wind ranges from about 11 mph on the calmest days to 12 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
112light breeze
212light breeze
312light breeze
412light breeze
512light breeze
612light breeze
712light breeze
812light breeze
912light breeze
1012light breeze
1112light breeze
1212light breeze
1312light breeze
1412light breeze
1512light breeze
1612light breeze
1712light breeze
1812light breeze
1912light breeze
2012light breeze
2111light breeze
2211light breeze
2311light breeze
2411light breeze
2511light breeze
2611light breeze
2711light breeze
2811light breeze
2911light breeze
3011light breeze
3111light 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 4:54 AM to 4:24 AM, and sunset from 6:43 PM to 7:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:546:43
213.84:536:44
313.94:526:45
413.94:506:46
514.04:496:47
614.04:486:48
714.04:466:49
814.14:456:50
914.14:446:51
1014.24:436:53
1114.24:426:54
1214.24:406:55
1314.34:396:56
1414.34:386:57
1514.34:376:58
1614.44:366:59
1714.44:357:00
1814.44:347:01
1914.54:337:02
2014.54:327:03
2114.54:317:04
2214.64:317:05
2314.64:307:06
2414.64:297:07
2514.74:287:08
2614.74:277:09
2714.74:277:10
2814.74:267:11
2914.84:257:11
3014.84:257:12
3114.84:247:13

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.9 kWh/m².

For context, solar energy here swings from a low near 1.48 kWh/m² to a high of 6.5 kWh/m² in June across the year — May's 5.9 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.6Bright
65.6Bright
75.6Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.8Bright
135.8Bright
145.8Bright
155.9Bright
165.9Bright
175.9Bright
186.0Bright
196.0Intense
206.0Intense
216.0Intense
226.1Intense
236.1Intense
246.1Intense
256.1Intense
266.2Intense
276.2Intense
286.2Intense
296.2Intense
306.2Intense
316.2Intense
Planning a trip in May

Is May a good time to visit Northbrook?

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

4.1
Sightseeing
6th-best month of the year
0.5
Beach & pool
6th-best month of the year

May is a reasonable time to visit Northbrook for sightseeing.

What to pack for Northbrook in May

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

In May, Northbrook sees daytime highs around 58°F and nights near 50°F. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Northbrook in May

The nearest coast averages about 44°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 11 mi away) is warmest in August at about 72°F and coldest in February near 36°F.

It's comfortable for a long swim from Jul 14 to Sep 14 — about 2.1 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr39Bracing
May44Bracing
Jun56Bracing
Jul69Refreshing
Aug72Refreshing
Sep68Refreshing
Oct58Bracing
Nov48Bracing
Dec42Bracing

UV index in Northbrook in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Northbrook peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 23UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May7Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Northbrook 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 Northbrook is worst in July — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 921 µg/m³Oct 2410 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar18Moderate
Apr19Moderate
May20Moderate
Jun21Moderate
Jul21Moderate
Aug18Moderate
Sep15Moderate
Oct10Good
Nov10Good
Dec11Good
Location & terrain

Where is Northbrook?

Northbrook sits at 42.1°N, 87.8°W, 646 ft above sea level, in United States. The nearest listed city is Deerfield, 3.1 mi away.

Topography around Northbrook

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

Within 2 miles, the terrain around Northbrook has only modest variations in elevation — a maximum elevation change of 135 ft around an average of 673 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 240 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 892 ft.

The land around Northbrook is covered by trees (46%) and artificial surfaces (35%) within 2 miles, trees (35%), artificial surfaces (29%) and water (25%) within 10 miles, and water (40%) within 50 miles.

2 miles
135 ft
10 miles
240 ft
50 miles
892 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Deerfield 3.1 mi · Highland Park 3.7 mi · Glenview 4.3 mi · Wheeling 5.0 mi · Prospect Heights 6.2 mi · Morton Grove 6.2 mi · Wilmette 6.8 mi · Buffalo Grove 6.8 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 Northbrook (42.1275°, -87.829°, elevation 646 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).