La Unión weather in May

In May, La Unión sees average daytime highs of 29°C and overnight lows near 20°C, with 3 mm of rain across 1.1 wet days and about 11.8 hours of daylight. It is the 6th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 30°C in the first days to 28°C by the end. The sky is clear or mostly clear about 49% of the time in May, and the air most often feels humid.

Daylight stretches from about 11 h 48 min at the start of May to 11 h 42 min by month's end. Set against the rest of the year, May is La Unión's 5th-clearest and 6th-windiest month. For the whole year in context, see La Unión's year-round climate.

Daytime high
29°
6th warmest
Overnight low
20°
8th coldest
Rainfall
3 mm
1.1 wet days
Daylight
11 h 48 min
6:27 AM – 6:12 PM
Cloud cover
45%
5th clearest
Wind
14 km/h
6th windiest
Solar energy
5.65 kWh/m²
Travel score
7.1
out of 10

La Unión is city in Piura, Peru.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 30°C in the first days to 28°C by the end.

A typical May day in La Unión reaches about 29°C in the afternoon and slips back to 20°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 31°C. Set against its neighbours, May runs about 2°C cooler than April and about 2°C warmer than June.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13021
23021
33021
43021
52921
62921
72921
82921
92920
102920
112920
122920
132920
142920
152920
162920
172920
182920
192820
202820
212820
222820
232820
242820
252820
262820
272820
282819
292819
302819
312819

How May really feels in La Unión

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

La Unión weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 22°232.712.35.5
Feb31° / 23°375.612.24.7
Mar31° / 23°586.9124.5
Apr30° / 22°213.611.95.6
May29° / 20°31.111.87.1
Jun26° / 19°10.311.78.4
Jul25° / 18°00.111.78.8
Aug25° / 17°00.111.89.0
Sep26° / 17°10.3128.5
Oct26° / 18°20.812.18.1
Nov27° / 18°41.212.27.7
Dec29° / 20°102.612.36.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 21% of May, with mostly cloudy or overcast conditions the remaining 30%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16931
26931
37129
47129
57327
67327
77426
87426
97426
107426
117426
127426
137327
147228
157228
167030
177030
186931
196733
206733
216634
226634
236634
246634
256634
266634
276634
286733
296733
306931
316931

Chance of precipitation in May

Any precipitation

La Unión gets around 3 mm of rain over 1.1 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 4% and peaks near 6% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
16
26
36
46
56
66
75
85
95
105
115
125
134
144
154
164
174
183
193
203
213
223
232
242
252
262
272
282
292
302
312

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the humid band about 64% of days. Sticky, muggy-or-worse air turns up on roughly 34% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1050474
2051463
3051463
4053452
5054442
6055432
7057421
8057421
9058411
10059401
11060391
12062380
13063370
14064360
15065350
16066340
17166330
18167320
19169300
20170290
21270280
22271270
23371260
24371260
25471250
26472240
27572230
28671230
29672220
30771220
31772210

Wind in May

Winds average 14 km/h in May.

Across May, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 48 min at the start of May to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over May. Sunrise moves from 6:26 AM to 6:29 AM, and sunset from 6:15 PM to 6:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:266:15
211.86:266:14
311.86:266:14
411.86:266:14
511.86:266:14
611.86:266:13
711.86:266:13
811.86:266:13
911.86:266:13
1011.86:266:13
1111.86:266:12
1211.86:266:12
1311.86:266:12
1411.86:266:12
1511.86:266:12
1611.86:276:12
1711.86:276:12
1811.76:276:12
1911.76:276:12
2011.76:276:12
2111.76:276:12
2211.76:276:12
2311.76:286:11
2411.76:286:11
2511.76:286:11
2611.76:286:12
2711.76:286:12
2811.76:286:12
2911.76:296:12
3011.76:296:12
3111.76:296:12

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.65 kWh/m².

For context, solar energy here swings from a low near 5.3 kWh/m² to a high of 6.62 kWh/m² in October across the year — May's 5.65 kWh/m² sits near the bottom.

0246151015202531
Solar energy (kWh/m²)Level
15.9Bright
25.8Bright
35.8Bright
45.8Bright
55.8Bright
65.8Bright
75.8Bright
85.8Bright
95.8Bright
105.8Bright
115.8Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.7Bright
175.7Bright
185.6Bright
195.6Bright
205.6Bright
215.6Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.4Bright
305.4Bright
315.4Bright
Planning a trip in May

Is May a good time to visit La Unión?

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

7.1
Sightseeing
7th-best month of the year
8.5
Beach & pool
1st-best month of the year

May is one of the better times to visit La Unión for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for La Unión in May

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

In May, La Unión sees daytime highs around 29°C and nights near 20°C. Pack light clothes. Worth having: sun protection.

light clothessun protection

Sea temperature near La Unión in May

The nearest coast averages about 20°C 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 29 km away) is warmest in February at about 23°C and coldest in September near 18°C.

It's comfortable for a long swim from Dec 25 to May 15 — about 4.7 months when the water holds above 20°C.

16°18°20°22°24°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb23Refreshing
Mar23Refreshing
Apr21Refreshing
May20Refreshing
Jun19Cool
Jul18Cool
Aug18Cool
Sep18Cool
Oct18Cool
Nov19Cool
Dec20Cool

UV index in La Unión in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in La Unión peaks around February 19 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 22 at about 10 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeFeb 19UV 16Jun 22UV 10
UV index (midday)Level
Jan15Extreme
Feb16Extreme
Mar16Extreme
Apr13Extreme
May12Extreme
Jun10Very high
Jul10Extreme
Aug11Extreme
Sep12Extreme
Oct14Extreme
Nov13Extreme
Dec13Extreme
Location & terrain

Where is La Unión?

La Unión sits at 5.4°S, 80.7°W, 15 m above sea level, in Peru. The nearest listed city is Catacaos, 16 km away.

Topography around La Unión

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of La Unión.

Within 3 km, the terrain around La Unión has only modest variations in elevation — a maximum elevation change of 25 m around an average of 14 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 76 m; within 80 km, significant variations in elevation — a maximum elevation change of 588 m.

The land around La Unión is covered by cropland (57%) within 3 km, bare terrain (50%) and cropland (33%) within 16 km, and bare terrain (47%) and water (24%) within 80 km.

3 km
25 m
16 km
76 m
80 km
588 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Catacaos 16 km · Sechura 19 km · San Martin 25 km · Piura 26 km · Paita 54 km · Sullana 56 km · Marcavelica 58 km · Querecotillo 64 km

Peru travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B / C
220 V · 60 Hz
Prices
≈ 51% of US
price level, 2025
GDP per capita
$9,684
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
49%
of population, 2024
Homicide rate
8.6
per 100k, 2021
Road deaths
13.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 519
Religion
Catholic 76%Evangelical Christian 16%no religion 5%other religions 3%

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 La Unión (-5.4023°, -80.7422°, elevation 15 m), 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).