Climate Insights for Onslow

The climate in Onslow is hot. The average annual temperature is 27°C and approximately 191mm of precipitation falls per year. March is the wettest month, receiving around 43mm of rainfall. Onslow 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: January, December, February. The coldest months are July, August, June, when temperatures can drop to 14°C.

Temperatures in Onslow vary considerably across the year, with a 23°C difference between the coldest and warmest months. January is the hottest month, with daytime highs reaching 37°C and an average of 31°C. July is the coolest month, with minimum temperatures around 14°C and an average of 20°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 5°C shift in average temperatures.

Onslow is a quite dry location, receiving approximately 191mm of precipitation annually, which averages out to around 16mm per month. The wettest month is March, averaging 43mm of rainfall. May and June also tend to see above-average precipitation. The driest month is October, with just 0mm. That's 43mm less than March, 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.

Onslow is moderately windy, with an average annual wind speed of 25km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 29km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in June, with average winds dropping to 20km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 9km/h gap between the calmest and windiest months. Wind tends to pick up during the summer months. The seasonal averages are 21km/h in winter, 27km/h in spring, 28km/h in summer, 22km/h in autumn.

It is currently autumn in Onslow, which began on March 20, 2026. Onslow 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 January at around 37°C, while the coldest stretch bottoms out in July near 14°C. Winter is next, beginning on June 21, 2026 — 88 days from now.

The best time to visit Onslow is during May, June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 22°C with modest rainfall averaging 17mm per month. By contrast, January can be uncomfortably hot with temperatures reaching 37°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Onslow 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.