Weather in Guanacaste in July

How July compares

July is the 8th warmest month of the year in Guanacaste and ranks 47th of 134 destinations we compare for July - see where else is hot in July. Against London's average high of 21.8°C in July, Guanacaste is 7.7°C warmer by day and 9.5°C warmer at night.

Daytime and night-time in July

The typical July day in Guanacaste peaks at 29.5°C, but that is an average: the warmest 10% of days reach 31.3°C or more. About 99% of days top 25°C and 1 in 3 pass 30°C. Nights average 23.0°C; one night in ten drops to 22.0°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest July day here reached 33.8°C (2019-07-30) and the coldest night 20.3°C (2019-07-31).

Rain in July

Wet (more than 8 rainy days): about 17 days with 1 mm or more, 169 mm in total. Year to year it varies a lot - the wettest July was 2010 with 520 mm, the driest 2014 with 17 mm. Humidity averages 83%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in July

The sea averages 28.6°C - warm enough to swim (22°c+). Depending on the year it ranges from 28.2°C to 29.0°C. For the warmest sea here, come in May (28.9°C).

Sunshine and daylight

Around 2.0 hours of sunshine a day (estimated from cloud cover), 12.6 hours of daylight: the sun rises about 05:27 and sets about 18:08 local time in mid-July. Average cloud cover is 84%.

Is July 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, with little cooling overnight

Average highs of 29.5°C mean light clothing is the sensible starting point, but humidity of 83% makes this less appealing if you dislike sticky heat. Days reach 30°C around 35% of the time, so allow yourself a slower pace and somewhere shaded to rest around midday. Nights average 23°C, which offers some relief without turning cool; check that your accommodation has cooling you are comfortable sleeping with. Pack breathable clothes rather than a wardrobe built around layers. July suits travellers happy in sustained warmth, but it is a less comfortable choice if cooler evenings are an important part of your holiday.

Rain needs room in your plans

About 17 days have measurable rain, so wet weather needs to be part of the plan rather than treated as an unlikely interruption. Sunshine averages only about 2.0 hours within 12.6 hours of daylight: there is time to be outdoors, but bright sun is a limited part of the average day. That does not mean rain falls continuously, nor does it justify assuming showers will arrive at a convenient time. Keep outdoor plans movable, pack a light waterproof and protect anything that should stay dry. July is a poor fit if your main aim is reliable sunshine, but more workable if you can change plans when rain arrives.

Warm sea, but weigh up the journey

The sea is a clear reason to consider July: at an average of 28.6°C, it is warm enough for comfortable swimming on temperature alone. The year-to-year range of 28°C to 29°C also leaves little reason to worry about chilly water. Warm water does not guarantee suitable swimming conditions, so judge those locally rather than using temperature as your only guide. With a London flight of about 11 h 42 min, this is a long-haul commitment. It makes more sense if warm air and sea matter more to you than sunshine; if grey skies would spoil the trip, consider a different month.