Jaco weather in May

In May, Jaco sees average daytime highs of 28°C and overnight lows near 26°C, with 405 mm of rain across 28.3 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 6% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of May to 12 h 30 min by month's end. Set against the rest of the year, May is Jaco's 7th-clearest and 6th-windiest month. For the whole year in context, see Jaco's year-round climate.

Daytime high
28°
4th warmest
Overnight low
26°
8th coldest
Rainfall
405 mm
28.3 wet days
Daylight
12 h 24 min
5:22 AM – 5:48 PM
Cloud cover
85%
7th clearest
Wind
10 km/h
6th windiest
Solar energy
4.86 kWh/m²
Travel score
3.6
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical May day in Jaco reaches about 28°C in the afternoon and slips back to 26°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 28°C. Set against its neighbours, May runs on par with April and on par with June.

24°26°28°30°32°151015202531
Avg high (°C)Avg low (°C)
12826
22826
32826
42826
52826
62826
72826
82826
92826
102826
112826
122826
132826
142826
152826
162826
172826
182826
192826
202826
212826
222826
232726
242726
252726
262726
272726
282726
292726
302726
312726

Jaco weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°286.311.57.4
Feb28° / 27°163.411.77.9
Mar28° / 27°235.811.97.3
Apr28° / 26°10818.412.25.1
May28° / 26°40528.312.43.6
Jun27° / 26°43028.412.63.4
Jul27° / 26°4562912.53.4
Aug27° / 26°50629.412.33.4
Sep27° / 25°47029.112.13.4
Oct27° / 25°57129.311.83.5
Nov27° / 25°37125.611.64.1
Dec27° / 26°12315.211.45.9

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 6% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 7% of May, with mostly cloudy or overcast conditions the remaining 87%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12674
22575
32575
42278
52278
62179
72080
81882
91882
101684
111684
121585
131585
141288
151288
161189
171090
181090
19892
20892
21793
22694
23694
24694
25694
26694
27694
28694
29694
30694
31595

Chance of precipitation in May

Any precipitation

Jaco gets around 405 mm of rain over 28.3 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 91% and peaks near 95% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
183
284
385
486
587
688
788
889
989
1090
1190
1290
1391
1491
1591
1692
1792
1892
1993
2093
2193
2293
2393
2493
2593
2693
2794
2894
2994
3094
3195

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 67% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
16337
26238
36238
46139
56139
66139
76139
86139
96139
106139
116238
126238
136337
146436
156436
166535
176634
186733
196832
206931
217030
227129
237228
247327
257426
267426
277426
287525
297525
307525
317525

Wind in May

Winds average 10 km/h in May.

Across May, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 18 min at the start of May to 12 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over May. Sunrise moves from 5:26 AM to 5:20 AM, and sunset from 5:46 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:265:46
212.35:255:46
312.35:255:46
412.45:255:46
512.45:245:46
612.45:245:46
712.45:245:46
812.45:235:47
912.45:235:47
1012.45:235:47
1112.45:235:47
1212.45:225:47
1312.45:225:47
1412.45:225:48
1512.45:225:48
1612.45:225:48
1712.45:215:48
1812.55:215:48
1912.55:215:49
2012.55:215:49
2112.55:215:49
2212.55:215:49
2312.55:215:49
2412.55:215:50
2512.55:215:50
2612.55:215:50
2712.55:205:50
2812.55:205:51
2912.55:205:51
3012.55:205:51
3112.55:205:51

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.86 kWh/m².

For context, solar energy here swings from a low near 4.12 kWh/m² to a high of 6.51 kWh/m² in March across the year — May's 4.86 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.3Bright
45.3Bright
55.2Bright
65.2Bright
75.2Bright
85.1Bright
95.1Bright
105.0Bright
115.0Bright
125.0Bright
134.9Bright
144.9Bright
154.9Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
314.6Bright
Planning a trip in May

Hazard calendar for Jaco

In seasonPeak

In May, Jaco sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Jaco's rainy season runs May–November, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Jaco?

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

3.6
Sightseeing
7th-best month of the year
3.9
Beach & pool
7th-best month of the year

May is a weaker month for outdoor sightseeing in Jaco.

What to pack for Jaco in May

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

In May, Jaco sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near Jaco in May

The nearest coast averages about 29°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 April at about 29°C and coldest in November near 28°C.

The water stays above 20°C all year — warm enough for a swim any month.

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov28Warm
Dec28Tropical

UV index in Jaco 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 Jaco peaks around March 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highMar 15UV 13Dec 17UV 9
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun13Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct11Extreme
Nov11Extreme
Dec9Very high

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

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 1617 µg/m³Jan 19 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr16Moderate
May18Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep14Moderate
Oct12Moderate
Nov11Good
Dec9Good
Location & terrain

Where is Jaco?

Jaco sits at 9.6°N, 84.6°W, 0 m above sea level, in Costa Rica. The nearest listed city is Esparza, 42 km away.

EsparzaChacaritaSan Rafael AbajoTejarPuntarenasSan_Ramon_Manuel AntonioAlajuela

Topography around Jaco

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

Within 3 km, the terrain around Jaco has significant variations in elevation — a maximum elevation change of 401 m around an average of 35 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 802 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,811 m.

The land around Jaco is covered by water (38%) and trees (31%) within 3 km, water (56%) and trees (35%) within 16 km, and trees (45%) and water (43%) within 80 km.

3 km
401 m
16 km
802 m
80 km
2,811 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
May weather nearby: Esparza 42 km · Chacarita 44 km · San Rafael Abajo 44 km · Tejar 46 km · Puntarenas 46 km · San_Ramon_ 55 km · Manuel Antonio 57 km · Alajuela 64 km

Costa Rica travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 59% of US
price level, 2025
GDP per capita
$19,970
2025
Happiness
7.4 / 10
World Happiness, 2025
Safe drinking water
81%
of population, 2024
Homicide rate
17.7
per 100k, 2023
Road deaths
14.8
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 516
Religion
Roman Catholic 48%none 27%Evangelical and Pentecostal 20%other 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 Jaco (9.615°, -84.6298°, elevation 0 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).