Climate Insights for Whanganui

The climate in Whanganui is temperate. The average annual temperature is 14°C and approximately 1188mm of precipitation falls per year. Whanganui receives a notable amount of rainfall throughout the year, including during its driest month. Whanganui 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, July, September, when temperatures can drop to 9°C.

Whanganui sees moderate temperature variation throughout the year, ranging from 9°C to 20°C. February is the warmest month, though highs remain moderate at 20°C with a mean of 18°C. August is the coolest month, with minimum temperatures around 9°C and an average of 11°C. Daily temperature variation is modest, with an average difference of 3°C between highs and lows.

Whanganui is a moderately rainy area, receiving approximately 1188mm of precipitation annually, which averages out to around 99mm per month. The wettest month is July, averaging 118mm of rainfall. May and August also tend to see above-average precipitation. The driest month is January, with just 71mm. That's 47mm less than July, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around.

Whanganui is very windy, with an average annual wind speed of 30km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is September, averaging 34km/h, which can feel quite blustery and may affect outdoor activities. The calmest conditions occur in March, with average winds dropping to 27km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 7km/h between the calmest and windiest months.

It is currently autumn in Whanganui, which began on March 20, 2026. Whanganui 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 20°C, while the coldest stretch bottoms out in August near 9°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Whanganui is during January, February, March and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 86mm per month. By contrast, August can be quite cold with temperatures dropping to 9°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Whanganui 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.