Guanacaste weather in May
Guanacaste averages 31°C by day and 25°C at night in May, with the sea at 30°C and about 267 mm of rain in the month. It cools by about 2°C into June.
Day
31°C
Night
25°C
Sea
30°C
Rain
267 mm
Flight from London
11h
What May feels like
May is hot but wet in Guanacaste: rainy season, so pack for showers.
The sea is warm at 30°C: comfortable for long swims.
It is rainy season: about 267 mm of rain falls in the month.
That is 13°C warmer than an average May day in London.
Of the 56 sun destinations we track, Guanacaste is the #10 warmest in May.
Want it warmer in May?
These are hotter than Guanacaste this month for at most an hour and a half more flying:
Guanacaste weather by month
May is highlighted. Compare with April and June, or see the full year in Guanacaste.
| Month | Day | Night | Sea | Rain |
|---|---|---|---|---|
| January | 32°C | 25°C | 28°C | 14 mm |
| February | 34°C | 25°C | 28°C | 6 mm |
| March | 34°C | 25°C | 29°C | 15 mm |
| April | 34°C | 26°C | 30°C | 70 mm |
| May | 31°C | 25°C | 30°C | 267 mm |
| June | 29°C | 24°C | 30°C | 379 mm |
| July | 30°C | 25°C | 30°C | 240 mm |
| August | 30°C | 24°C | 30°C | 295 mm |
| September | 29°C | 24°C | 30°C | 346 mm |
| October | 29°C | 24°C | 29°C | 502 mm |
| November | 29°C | 24°C | 28°C | 214 mm |
| December | 31°C | 24°C | 29°C | 37 mm |
Guanacaste in May: quick answers
Is Guanacaste hot in May?
May is hot but wet in Guanacaste: rainy season, so pack for showers. Average highs are 31°C and lows 25°C.
Can you swim in Guanacaste in May?
The sea is warm at 30°C: comfortable for long swims.
Does it rain in Guanacaste in May?
It is rainy season: about 267 mm of rain falls in the month.
What is the warmest month in Guanacaste?
March, at an average high of 34°C. The coolest is October at 29°C.
How long is the flight to Guanacaste from the UK?
About 11h direct from London, estimated from the 8,795 km distance. Check your airline for exact times.
Still choosing? See where is hot in May for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in May from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. Rain is the average monthly total. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning Guanacaste in May?
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