Hillsborough weather in May

In May, Hillsborough sees average daytime highs of 71°F and overnight lows near 53°F, with 3.6 in of rain across 11.7 wet days and about 14.2 hours of daylight. It is the 5th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 67°F in the first days to 76°F by the end. The sky is clear or mostly clear about 24% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of May to 14 h 36 min by month's end. Set against the rest of the year, May is Hillsborough's 12th-clearest and 8th-windiest month. For the whole year in context, see Hillsborough's year-round climate.

Daytime high
71°
5th warmest
Overnight low
53°
8th coldest
Rainfall
3.6 in
11.7 wet days
Daylight
14 h 12 min
4:48 AM – 7:02 PM
Cloud cover
64%
12th clearest
Wind
6 mph
8th windiest
Solar energy
5.6 kWh/m²
Travel score
6.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 67°F in the first days to 76°F by the end.

A typical May day in Hillsborough reaches about 71°F in the afternoon and slips back to 53°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 59°F and 84°F. Set against its neighbours, May runs about 10°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16748
26749
36749
46849
56849
66850
76850
86950
96951
106951
116951
127051
137052
147052
157152
167153
177153
187253
197253
207354
217354
227355
237455
247455
257456
267556
277556
287657
297657
307658
317658

How May really feels in Hillsborough

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.

Hillsborough weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 25°3.39.14.39.40.0
Feb42° / 26°3.093.710.40.3
Mar50° / 33°4.210.63.311.72.2
Apr62° / 43°3.710.70.4135.0
May71° / 53°3.611.7014.26.3
Jun81° / 62°4.311.5014.86.0
Jul85° / 68°4.211.3014.65.0
Aug83° / 66°4.010.4013.65.8
Sep76° / 59°4.19.2012.36.9
Oct65° / 47°3.78.60.110.96.0
Nov53° / 38°3.07.90.59.73.2
Dec44° / 30°4.09.62.69.20.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in May, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24159
34357
44258
54357
64258
74357
84258
94258
104258
114159
124258
134258
144159
154258
164258
174258
184258
194258
204258
214258
224258
234357
244357
254357
264456
274357
284357
294357
304456
314456

Chance of precipitation in May

Any precipitation

Hillsborough gets around 3.6 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 37% and peaks near 38% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
336
437
537
637
737
838
938
1038
1138
1238
1338
1438
1537
1637
1737
1837
1937
2037
2137
2237
2337
2437
2537
2637
2738
2838
2938
3038
3138

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 70% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
18710300
28610400
38511400
48412400
58312500
68213500
78113600
87914610
97814710
107814710
117714810
127714810
137614910
1474141020
1574141020
1672151120
1771151130
1870151230
1968161240
2067161340
2164171450
2262171560
2361181560
2459181670
2558181770
2657181780
2755191880
2853191990
2952191991
30502020101
31492020101

Wind in May

Winds average 6 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
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 36 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 5:05 AM to 4:36 AM, and sunset from 6:47 PM to 7:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:056:47
213.75:036:48
313.85:026:49
413.85:016:50
513.95:006:51
613.94:586:52
713.94:576:53
814.04:566:54
914.04:556:55
1014.04:546:56
1114.14:536:57
1214.14:526:58
1314.14:506:59
1414.24:497:00
1514.24:487:01
1614.24:487:02
1714.34:477:03
1814.34:467:04
1914.34:457:05
2014.44:447:06
2114.44:437:07
2214.44:427:08
2314.54:427:09
2414.54:417:09
2514.54:407:10
2614.54:397:11
2714.64:397:12
2814.64:387:13
2914.64:387:14
3014.64:377:15
3114.64:367:15

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.6 kWh/m².

For context, solar energy here swings from a low near 1.77 kWh/m² to a high of 5.99 kWh/m² in June across the year — May's 5.6 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
65.4Bright
75.4Bright
85.4Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.6Bright
165.6Bright
175.6Bright
185.6Bright
195.6Bright
205.7Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.9Bright
Planning a trip in May

Hazard calendar for Hillsborough

In seasonPeak

None of Hillsborough's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Hillsborough sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Hillsborough?

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

6.3
Sightseeing
2nd-best month of the year
4.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Hillsborough for sightseeing.

What to pack for Hillsborough in May

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

In May, Hillsborough sees daytime highs around 71°F and nights near 53°F. Worth packing: rain gear and sun protection. About 12 days see rain.

rain gearsun protection

Sea temperature near Hillsborough in May

The nearest coast averages about 55°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 40 mi away) is warmest in August at about 74°F and coldest in February near 40°F.

It's comfortable for a long swim from Jun 30 to Sep 27 — about 3 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan43Bracing
Feb40Bracing
Mar41Bracing
Apr46Bracing
May55Bracing
Jun65Cool
Jul72Refreshing
Aug74Refreshing
Sep71Refreshing
Oct64Cool
Nov55Bracing
Dec49Bracing

UV index in Hillsborough 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 Hillsborough peaks around July 11 at about 8 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 8Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Hillsborough 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 Hillsborough is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1518 µg/m³Nov 149 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar14Moderate
Apr14Moderate
May16Moderate
Jun17Moderate
Jul18Moderate
Aug15Moderate
Sep13Moderate
Oct10Good
Nov9Good
Dec10Good
Location & terrain

Where is Hillsborough?

Hillsborough sits at 40.5°N, 74.6°W, 85 ft above sea level, in United States. The nearest listed city is Somerset, 7.5 mi away.

Topography around Hillsborough

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

Within 2 miles, the terrain around Hillsborough has only modest variations in elevation — a maximum elevation change of 161 ft around an average of 105 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 673 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,962 ft.

The land around Hillsborough is covered by trees (56%) and grassland (29%) within 2 miles, trees (64%) and grassland (22%) within 10 miles, and trees (61%) within 50 miles.

2 miles
161 ft
10 miles
673 ft
50 miles
1,962 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Somerset 7.5 mi · North Brunswick 8.1 mi · Bridgewater 8.7 mi · Princeton 9.3 mi · New Brunswick 9.3 mi · Warren Township 11 mi · East Brunswick 12 mi · Edison 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 Hillsborough (40.4776°, -74.6268°, elevation 85 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).