Weather in Guanacaste in October

How October compares

October is the 12th warmest month of the year in Guanacaste and ranks 26th of 134 destinations we compare for October - see where else is hot in October. Against London's average high of 14.6°C in October, Guanacaste is 13.7°C warmer by day and 13.8°C warmer at night.

Daytime and night-time in October

The typical October day in Guanacaste peaks at 28.3°C, but that is an average: the warmest 10% of days reach 30.0°C or more. About 97% of days top 25°C and 1 in 10 pass 30°C. Nights average 22.2°C; one night in ten drops to 21.4°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest October day here reached 32.3°C (2020-10-11) and the coldest night 19.5°C (2005-10-27).

Rain in October

Wet (more than 8 rainy days): about 25 days with 1 mm or more, 382 mm in total. Year to year it varies a lot - the wettest October was 2018 with 730 mm, the driest 2000 with 108 mm. Humidity averages 90%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in October

The sea averages 28.3°C - warm enough to swim (22°c+). Depending on the year it ranges from 27.7°C to 28.9°C. For the warmest sea here, come in May (28.9°C).

Sunshine and daylight

Around 1.7 hours of sunshine a day (estimated from cloud cover), 11.8 hours of daylight: the sun rises about 05:31 and sets about 17:24 local time in mid-October. Average cloud cover is 86%.

Is October a good time to visit Guanacaste?

It is a reasonable choice: hot days but expect showers. The best months for Guanacaste on our scoring are February, January, December; months averaging 25°C or more: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

Hot days, warm nights and high humidity

October is Guanacaste's coolest month by average daytime temperature, but that does not make it cool for a UK traveller. Highs average 28°C, compared with London's 14.6°C in October, and nights average 22°C. Light, loose clothing makes more sense than a wardrobe built around cool evenings. Humidity averages 90%, so the warmth can feel sticky and breathable fabrics are a sensible choice. Keep strenuous plans flexible and give yourself breaks rather than assuming the lower seasonal temperatures mean comfortable conditions for exertion. For accommodation, consider how you will keep cool at night, not just during the day.

Rain is the main reason to think twice

With about 25 rainy days, October is a poor choice if your holiday depends on staying outdoors in dry weather. That figure does not mean constant rain, but it does mean you should expect wet conditions to affect your plans regularly. Pack a lightweight waterproof and protection for belongings, and avoid making every day depend on clear skies. Sunshine averages only 1.7 hours out of 11.8 hours of daylight, so long daylight hours should not be confused with long sunny spells. This month suits a relaxed schedule with room to change plans much better than a tightly arranged outdoor holiday.

Warm water, but limited sunbathing weather

The sea is a clear positive: at an average 28.3°C, it is warm enough for swimming without the chilly entry you might associate with a UK beach holiday. That makes October more appealing if water temperature matters more to you than blue skies. Still, a warm sea does not cancel out the rain or guarantee suitable swimming conditions at any particular moment; follow local advice before entering the water. Think of beach time as something to fit around the weather rather than the fixed centre of every day. Pack sun protection for brighter spells, alongside your wet-weather kit.