Climate Overview
The climate in Koster is hot. The average annual temperature is 27°C and approximately 204mm of precipitation falls per year. March is the wettest month, receiving around 33mm of rainfall. Koster 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: April, January, March. The coldest months are November, December, October, when temperatures can drop to 25°C.
Temperature
Koster has relatively stable temperatures year-round, staying within a 4°C range. The warmest month is April, when average highs reach 29°C and the mean temperature sits around 28°C. November is the coolest month, with minimum temperatures around 25°C and an average of 25°C. Daily temperature variation is modest, with an average difference of 1°C between highs and lows.
Precipitation
Koster is a quite dry location, receiving approximately 204mm of precipitation annually, which averages out to around 17mm per month. The wettest month is January, averaging 33mm of rainfall. February and March also tend to see above-average precipitation. The driest month is August, with just 2mm. That's 31mm 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
Koster is relatively calm, with an average annual wind speed of 5km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is May, averaging 6km/h, though still comfortable for most outdoor activities. The calmest conditions occur in December, with average winds dropping to 4km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 2km/h gap between the calmest and windiest months.
Seasons
16 days until Spring
It is currently winter in Koster, which began on June 21, 2026. Koster 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 April at around 29°C, while the coldest stretch bottoms out in November near 25°C. Spring is next, beginning on September 23, 2026 (16 days from now).
Spring
Temperatures range from 25 to 27°C. Precipitation is minimal, with only around 29mm for the entire season. Winds are generally light, averaging 5km/h. Light layers work well as temperatures warm through the season. It is a great time to be outdoors.
Summer
Temperatures range from 25 to 29°C. Rainfall is relatively light, with around 85mm over the season and a monthly average of 28mm. Winds are generally light, averaging 5km/h. Light, breathable clothing is ideal. Perfect conditions for outdoor activities.
Autumn
Temperatures range from 27 to 29°C. Rainfall is relatively light, with around 61mm over the season and a monthly average of 20mm. Winds are generally light, averaging 6km/h. Layered clothing works best as temperatures gradually cool. Enjoy the crisp air and changing scenery.
Winter
Temperatures range from 26 to 28°C. Precipitation is minimal, with only around 29mm for the entire season. Winds are generally light, averaging 5km/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 Koster 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.
