Guanacaste weather in August
Guanacaste averages 30°C by day and 24°C at night in August, with the sea at 30°C and about 295 mm of rain in the month.
Day
30°C
Night
24°C
Sea
30°C
Rain
295 mm
Flight from London
11h
What August feels like
August 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 295 mm of rain falls in the month.
That is 7°C warmer than an average August day in London.
Of the 56 sun destinations we track, Guanacaste is the #32 warmest in August.
Want it warmer in August?
These are hotter than Guanacaste this month for at most an hour and a half more flying:
Guanacaste weather by month
August is highlighted. Compare with July and September, 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 August: quick answers
Is Guanacaste hot in August?
August is hot but wet in Guanacaste: rainy season, so pack for showers. Average highs are 30°C and lows 24°C.
Can you swim in Guanacaste in August?
The sea is warm at 30°C: comfortable for long swims.
Does it rain in Guanacaste in August?
It is rainy season: about 295 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 August for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in August 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 August?
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