Costa Rica weather in May

In May, Costa Rica sees average daytime highs of 28°C and overnight lows near 18°C, with 39 mm of rain across 5.7 wet days and about 11.1 hours of daylight. It is the 11th-warmest and 9th-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 50% of the time in May, and the air most often feels humid.

Daylight stretches from about 11 h 18 min at the start of May to 11 hours by month's end. Set against the rest of the year, May is Costa Rica's 5th-clearest and 5th-windiest month. For the whole year in context, see Costa Rica's year-round climate.

Daytime high
28°
11th warmest
Overnight low
18°
3rd coldest
Rainfall
39 mm
5.7 wet days
Daylight
11 h 06 min
6:55 AM – 6:03 PM
Cloud cover
45%
5th clearest
Wind
8 km/h
5th windiest
Solar energy
4.48 kWh/m²
Travel score
7.0
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 Costa Rica reaches about 28°C in the afternoon and slips back to 18°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 31°C. Set against its neighbours, May runs about 2°C cooler than April and on par with June.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12919
22919
32919
42918
52918
62918
72818
82818
92818
102818
112818
122818
132818
142818
152818
162818
172818
182818
192817
202817
212817
222817
232817
242817
252817
262817
272817
282817
292817
302817
312817

How May really feels in Costa Rica

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.

Costa Rica weather by month

How May compares with the rest of the year at a glance. May is the 11th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 21°25626.2133.3
Feb29° / 21°21523.612.63.3
Mar30° / 21°18123.812.13.6
Apr29° / 20°8112.411.65.0
May28° / 18°395.711.17.0
Jun28° / 17°182.410.97.9
Jul28° / 16°111.4117.6
Aug30° / 18°172.511.46.0
Sep31° / 20°678.711.94.5
Oct31° / 21°12918.512.43.7
Nov30° / 21°17522.212.93.5
Dec29° / 21°21725.613.13.4

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 34%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17030
27030
36931
46931
56832
66733
76634
86535
96337
106337
116238
126238
136139
146139
156040
166139
176139
186238
196238
206337
216436
226535
236634
246733
256832
266931
276931
287030
297129
307129
317129

Chance of precipitation in May

Any precipitation

Costa Rica gets around 39 mm of rain over 5.7 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 18% and peaks near 21% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
119
218
317
417
517
617
717
817
917
1018
1118
1218
1318
1419
1519
1620
1720
1821
1921
2021
2121
2221
2320
2420
2519
2619
2718
2818
2917
3016
3115

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 38% of days. Sticky, muggy-or-worse air turns up on roughly 20% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
182237321
282338301
392438291
4102538271
5102638261
6102638250
7112738240
8112838230
9112838220
10122838210
11122839210
12122939200
13132939200
14132839190
15142838190
16142838190
17152838190
18162838190
19162837180
20172837180
21172837180
22182837170
23182837170
24192837160
25192837160
26192837160
27192937150
28192937140
29193037140
30193137130
31193237120

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
289calm
299calm
309calm
319calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 18 min at the start of May to 11 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over May. Sunrise moves from 6:50 AM to 7:01 AM, and sunset from 6:10 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.36:506:10
211.36:506:09
311.36:506:09
411.36:516:08
511.36:516:08
611.36:516:07
711.26:526:07
811.26:526:06
911.26:526:06
1011.26:536:05
1111.26:536:05
1211.26:536:04
1311.26:546:04
1411.26:546:03
1511.16:556:03
1611.16:556:03
1711.16:556:02
1811.16:566:02
1911.16:566:02
2011.16:566:01
2111.16:576:01
2211.16:576:01
2311.16:586:01
2411.06:586:00
2511.06:586:00
2611.06:596:00
2711.06:596:00
2811.06:596:00
2911.07:005:59
3011.07:005:59
3111.07:015:59

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.48 kWh/m².

For context, solar energy here swings from a low near 4.17 kWh/m² to a high of 5.99 kWh/m² in October across the year — May's 4.48 kWh/m² sits near the bottom.

024151015202531
Solar energy (kWh/m²)Level
14.9Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.7Bright
74.7Bright
84.7Bright
94.6Bright
104.6Bright
114.6Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.4Bright
194.4Bright
204.3Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.3Bright
264.3Bright
274.3Bright
284.2Bright
294.2Bright
304.2Bright
314.2Bright
Planning a trip in May

Hazard calendar for Costa Rica

In seasonPeak

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

Costa Rica's monsoon runs October–March, when most of the year's rain falls.

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

Is May a good time to visit Costa Rica?

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

7.0
Sightseeing
3rd-best month of the year
7.7
Beach & pool
4th-best month of the year

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

What to pack for Costa Rica in May

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

In May, Costa Rica sees daytime highs around 28°C and nights near 18°C. Pack light clothes. About 6 days see rain.

light clothes

UV index in Costa Rica in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Costa Rica peaks around January 22 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 7 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeJan 22UV 15Jun 21UV 7
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar14Extreme
Apr11Extreme
May8Very high
Jun7Very high
Jul8Very high
Aug9Very high
Sep9Very high
Oct10Extreme
Nov13Extreme
Dec14Extreme

Air quality in Costa Rica 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 Costa Rica is worst in September — around 24 µg/m³ PM2.5 (moderate), about 5.2× the cleanest month (June, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1722 µg/m³Jun 125 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar6Good
Apr5Good
May5Good
Jun5Good
Jul8Good
Aug10Good
Sep24Moderate
Oct12Moderate
Nov6Good
Dec6Good
Location & terrain

Where is Costa Rica?

Costa Rica sits at 18.5°S, 53.1°W, 646 m above sea level, in Brazil. The nearest listed city is Chapadão do Sul, 60 km away.

Topography around Costa Rica

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

Within 3 km, the terrain around Costa Rica has only modest variations in elevation — a maximum elevation change of 160 m around an average of 655 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 307 m; within 80 km, large variations in elevation — a maximum elevation change of 616 m.

The land around Costa Rica is covered by grassland (39%) and trees (22%) within 3 km, cropland (41%), grassland (28%) and trees (27%) within 16 km, and cropland (42%), grassland (31%) and trees (23%) within 80 km.

3 km
160 m
16 km
307 m
80 km
616 m
treesshrubsgrasslandcroplandartificial surfaceswater
May weather nearby: Chapadão do Sul 60 km · Mineiros 124 km · Alto Araguaia 137 km · Cassilândia 160 km · Jataí 166 km · Coxim 172 km · São Gabriel do Oeste 178 km · Rio Verde de Mato Grosso 185 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Costa Rica (-18.5439°, -53.1292°, elevation 646 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. 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).