Climate Insights for Mejillones

The climate in Mejillones is temperate. The average annual temperature is 17°C and approximately 31mm of precipitation falls per year. July is the wettest month, receiving around 6mm of rainfall. Mejillones 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: February, January, March. The coldest months are August, September, July, when temperatures can drop to 14°C.

Mejillones has relatively stable temperatures year-round, staying within a 9°C range. February is the warmest month, though highs remain moderate at 23°C with a mean of 21°C. August is the coolest month, with minimum temperatures around 14°C and an average of 15°C. Daily temperature variation is modest, with an average difference of 3°C between highs and lows.

Mejillones is a quite dry location, receiving approximately 31mm of precipitation annually, which averages out to around 3mm per month. The wettest month is July, averaging 6mm of rainfall. August and June also tend to see above-average precipitation. The driest month is February, with just 0mm. 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.

Mejillones is mildly breezy, with an average annual wind speed of 20km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in March, with average winds dropping to 19km/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.

It is currently autumn in Mejillones, which began on March 20, 2026. Mejillones 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 February at around 23°C, while the coldest stretch bottoms out in August near 14°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Mejillones is during January, February, March, April, May, June, July, August, September, October, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 3mm per month. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Mejillones 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.