Climate Overview
The climate in Ascensión is warm and mild. The average annual temperature is 25°C and approximately 1467mm of precipitation falls per year. January is the wettest month, receiving around 247mm of rainfall. Ascensión is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: September, October, November. The coldest months are July, June, August, when temperatures can drop to 17°C.
Temperature
Ascensión sees moderate temperature variation throughout the year, ranging from 17°C to 32°C. The warmest month is September, when average highs reach 32°C and the mean temperature sits around 26°C. July is the coolest month, with minimum temperatures around 17°C and an average of 22°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs. The sharpest temperature change occurs between August and September, with a 2°C shift in average temperatures.
Precipitation
Ascensión is a fairly wet location, receiving approximately 1467mm of precipitation annually, which averages out to around 122mm per month. The wettest month is January, averaging 247mm of rainfall. February and December also tend to see above-average precipitation. The driest month is July, with just 6mm. That's 241mm less than January, 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
Ascensión is relatively calm, with an average annual wind speed of 2km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is August, averaging 3km/h, though still comfortable for most outdoor activities. The calmest conditions occur in March, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 1km/h between the calmest and windiest months.
Seasons
92 days until Spring
It is currently winter in Ascensión, which began on June 21, 2026. Ascensión is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in September at around 32°C, while the coldest stretch bottoms out in July near 17°C. Spring is next, beginning on September 23, 2026 — 92 days from now.
Spring
Temperatures range from 21 to 32°C. Rainfall is heavy, totalling around 348mm across the season with a monthly average of 116mm. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 22 to 30°C. Rainfall is heavy, totalling around 695mm across the season with a monthly average of 232mm. Winds are generally light, averaging 2km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 19 to 30°C. Rainfall is heavy, totalling around 341mm across the season with a monthly average of 114mm. Winds are generally light, averaging 2km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 17 to 31°C. Rainfall is relatively light, with around 83mm over the season and a monthly average of 28mm. Winds are generally light, averaging 3km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Best Time to Visit
The best time to visit Ascensión is during May, June, July and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 23°C with modest rainfall averaging 36mm per month. By contrast, September can be uncomfortably hot with temperatures reaching 32°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.
Monthly Climate Data
The table below shows monthly climate averages for Ascensión 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.
