Weather in Guanacaste in June

How June compares

June is the 7th warmest month of the year in Guanacaste and ranks 24th of 134 destinations we compare for June - see where else is hot in June. Against London's average high of 19.6°C in June, Guanacaste is 9.9°C warmer by day and 11.8°C warmer at night.

Daytime and night-time in June

The typical June day in Guanacaste peaks at 29.5°C, but that is an average: the warmest 10% of days reach 31.0°C or more. About 100% of days top 25°C and 1 in 3 pass 30°C. Nights average 23.1°C; one night in ten drops to 22.2°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest June day here reached 33.6°C (2015-06-02) and the coldest night 20.9°C (2001-06-04).

Rain in June

Wet (more than 8 rainy days): about 23 days with 1 mm or more, 279 mm in total. Year to year it varies a lot - the wettest June was 1995 with 499 mm, the driest 1994 with 77 mm. Humidity averages 86%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in June

The sea averages 28.8°C - warm enough to swim (22°c+). Depending on the year it ranges from 28.2°C to 29.4°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), 12.6 hours of daylight: the sun rises about 05:20 and sets about 18:05 local time in mid-June. Average cloud cover is 87%.

Is June 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, sticky evenings

The heat is dependable: days reach 25°C throughout June, with 35% reaching 30°C. Humidity averages 86%, so expect sticky conditions rather than dry warmth, especially when you are walking around. Keep strenuous plans flexible, take breaks from the midday heat and pack loose, lightweight clothing. Average night lows of 23.1°C mean evenings offer limited relief; light clothes will usually be more useful than substantial layers. If you struggle to sleep in warm conditions, prioritise accommodation with cooling. June suits travellers comfortable with persistent warmth, but it is a less comfortable choice if you prefer cool evenings or active days without frequent breaks.

Plan around wet weather, not guaranteed sunshine

Rain is the main compromise, with about 22 rainy days and only around 1.7 hours of sunshine a day. That does not mean rain falls continuously, but you should not build the trip around dependable sunny spells. Nor should you assume mornings will always be dry: the monthly figures do not establish a reliable daily window. Bring a lightweight waterproof and footwear you are comfortable getting wet, and leave room to change outdoor plans. There are 12.6 hours of daylight, so limited sunshine does not mean short days. June is a reasonable fit if warmth matters more than blue skies; it is harder to recommend for a sunshine-first holiday.