Callao weather in May

In May, Callao sees average daytime highs of 19°C and overnight lows near 18°C, with 2 mm of rain across 0.2 wet days and about 11.5 hours of daylight. It is the 6th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 19°C through the month. The sky is clear or mostly clear about 10% of the time in May, and the air most often feels humid.

Daylight stretches from about 11 h 36 min at the start of May to 11 h 24 min by month's end. Set against the rest of the year, May is Callao's 1st-clearest and 7th-windiest month. For the whole year in context, see Callao's year-round climate.

Daytime high
19°
6th warmest
Overnight low
18°
7th coldest
Rainfall
2 mm
0.2 wet days
Daylight
11 h 24 min
6:21 AM – 5:48 PM
Cloud cover
70%
1st clearest
Wind
18 km/h
7th windiest
Solar energy
4.89 kWh/m²
Travel score
7.1
out of 10

Callao is city and main seaport of Peru.

Air quality
High
PM2.5 25.5 µg/m³ · 2016
Density
8,343/km²
people per km²
Founded
1537

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 19°C through the month.

A typical May day in Callao reaches about 19°C in the afternoon and slips back to 18°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 20°C. Set against its neighbours, May runs about 2°C cooler than April and about 1°C warmer than June.

15°18°20°23°25°151015202531
Avg high (°C)Avg low (°C)
11918
21918
31918
41918
51918
61918
71918
81918
91918
101918
111918
121918
131918
141918
151918
161918
171918
181918
191918
201817
211817
221817
231817
241817
251817
261817
271817
281817
291817
301817
311817

Callao weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan22° / 20°51.512.67.4
Feb23° / 21°8212.47.4
Mar22° / 21°61.712.17.4
Apr20° / 19°20.211.77.4
May19° / 18°20.211.57.1
Jun18° / 17°51.111.36.5
Jul17° / 16°51.211.46.1
Aug16° / 15°51.211.66.0
Sep16° / 15°40.511.96.0
Oct17° / 16°30.312.36.2
Nov18° / 17°20.112.66.9
Dec20° / 19°30.612.77.1

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in May, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of May, with mostly cloudy or overcast conditions the remaining 72%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23565
33565
43565
53466
63466
73466
83268
93268
103169
113070
122971
132872
142773
152773
162575
172575
182575
192476
202575
212575
222575
232674
242674
252674
262674
272674
282575
292575
302575
312476

Chance of precipitation in May

Any precipitation

Callao gets around 2 mm of rain over 0.2 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 1% and peaks near 2% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
181
191
201
211
221
231
241
251
261
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 70% of days. Sticky, muggy-or-worse air turns up on roughly 11% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)
117821
217920
327919
428018
538017
647917
757916
867915
977815
1087814
1197714
12117613
13127612
14147412
15167311
16177310
1719729
1821709
1923698
2026677
2128657
2230646
2332635
2434615
2535605
2637594
2739574
2840564
2942544
3043543
3144533

Wind in May

Winds average 18 km/h in May.

Across May, daily wind ranges from about 17 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2018light breeze
2118light breeze
2218light breeze
2318light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze
3119light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 36 min at the start of May to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over May. Sunrise moves from 6:18 AM to 6:25 AM, and sunset from 5:53 PM to 5:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:185:53
211.66:195:53
311.66:195:52
411.56:195:52
511.56:195:51
611.56:195:51
711.56:195:51
811.56:205:50
911.56:205:50
1011.56:205:50
1111.56:205:49
1211.56:205:49
1311.56:215:49
1411.56:215:49
1511.56:215:48
1611.46:215:48
1711.46:225:48
1811.46:225:48
1911.46:225:48
2011.46:225:47
2111.46:235:47
2211.46:235:47
2311.46:235:47
2411.46:235:47
2511.46:245:47
2611.46:245:47
2711.46:245:47
2811.46:255:47
2911.46:255:46
3011.46:255:46
3111.46:255:46

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.89 kWh/m².

For context, solar energy here swings from a low near 4.37 kWh/m² to a high of 6.75 kWh/m² in November across the year — May's 4.89 kWh/m² sits near the bottom.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.1Bright
85.1Bright
95.1Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
144.9Bright
154.9Bright
164.9Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.8Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.7Bright
284.6Bright
294.6Bright
304.6Bright
314.6Bright
Planning a trip in May

Is May a good time to visit Callao?

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

7.1
Sightseeing
5th-best month of the year
2.8
Beach & pool
6th-best month of the year

May is one of the better times to visit Callao for general sightseeing.

What to pack for Callao in May

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

In May, Callao sees daytime highs around 19°C and nights near 18°C. Worth packing: sun protection.

sun protection

Sea temperature near Callao in May

The nearest coast averages about 19°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in February at about 22°C and coldest in September near 17°C.

It's comfortable for a long swim from Jan 1 to Apr 9 — about 3.3 months when the water holds above 20°C.

16°18°20°22°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb22Refreshing
Mar21Refreshing
Apr20Cool
May19Cool
Jun18Cool
Jul18Cool
Aug17Cool
Sep17Cool
Oct17Cool
Nov18Cool
Dec19Cool

UV index in Callao in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Callao peaks around February 12 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 22 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 12UV 15Jun 22UV 8
UV index (midday)Level
Jan14Extreme
Feb16Extreme
Mar13Extreme
Apr12Extreme
May10Very high
Jun8Very high
Jul8Very high
Aug10Extreme
Sep10Extreme
Oct13Extreme
Nov12Extreme
Dec13Extreme

Air quality in Callao 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 Callao is worst in March — around 30 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Callao's WHO annual average of 25.5 µg/m³.

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2030 µg/m³Nov 2022 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb27Moderate
Mar30Moderate
Apr28Moderate
May29Moderate
Jun28Moderate
Jul26Moderate
Aug25Moderate
Sep23Moderate
Oct23Moderate
Nov22Moderate
Dec22Moderate
Location & terrain

Where is Callao?

Callao sits at 12.1°S, 77.1°W, 5 m above sea level, in Peru. The nearest listed city is Carmen De La Legua Reynoso, 4.0 km away.

Topography around Callao

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

Within 3 km, the terrain around Callao has only modest variations in elevation — a maximum elevation change of 43 m around an average of 10 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 737 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,870 m.

The land around Callao is covered by artificial surfaces (54%) and water (33%) within 3 km, water (60%) and artificial surfaces (30%) within 16 km, and water (50%) and bare terrain (29%) within 80 km.

3 km
43 m
16 km
737 m
80 km
4,870 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Carmen De La Legua Reynoso 4.0 km · Breña 9.0 km · Jesus Maria 10 km · San Isidro 11 km · Lima 12 km · Miraflores 13 km · San Francisco De Borja 15 km · Barranco 16 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 Callao (-12.0516°, -77.1345°, elevation 5 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. 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).