Climate Overview
The climate in Arenal is hot. The average annual temperature is 28°C and approximately 1752mm of precipitation falls per year. May is the wettest month, receiving around 271mm of rainfall. Arenal sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Arenal sees moderate temperature variation throughout the year, ranging from 24°C to 36°C. February is the hottest month, with daytime highs reaching 36°C and an average of 30°C. October is the coolest month, with minimum temperatures around 24°C and an average of 27°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows.
Precipitation
Arenal is a fairly wet location, receiving approximately 1752mm of precipitation annually, which averages out to around 146mm per month. The wettest month is May, averaging 271mm of rainfall. October and April also tend to see above-average precipitation. The driest month is January, with just 21mm. That's 250mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Arenal is relatively calm, with an average annual wind speed of 7km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 8km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 6km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.
Seasons
89 days until Summer
It is currently spring in Arenal, which began on March 20, 2026. Arenal sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in February at around 36°C, while the coldest stretch bottoms out in October near 24°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 25 to 35°C. Rainfall is heavy, totalling around 548mm across the season with a monthly average of 183mm. Winds are generally light, averaging 7km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 25 to 33°C. Rainfall is heavy, totalling around 486mm across the season with a monthly average of 162mm. Winds are generally light, averaging 7km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 24 to 32°C. Rainfall is heavy, totalling around 612mm across the season with a monthly average of 204mm. Winds are generally light, averaging 6km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 24 to 36°C. Rainfall is relatively light, with around 106mm over the season and a monthly average of 35mm. Winds are generally light, averaging 7km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Arenal based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
