Climate Insights for Harrismith

The climate in Harrismith is temperate. The average annual temperature is 15°C and approximately 727mm of precipitation falls per year. December is the wettest month, receiving around 143mm of rainfall. Harrismith 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: December, January, February. The coldest months are July, June, August, when temperatures can drop to 2°C. Light snow can occur between September and October.

Temperatures in Harrismith vary considerably across the year, with a 24°C difference between the coldest and warmest months. The warmest month is December, when average highs reach 26°C and the mean temperature sits around 19°C. July is the coolest month, with minimum temperatures around 2°C and an average of 9°C. On average, daily temperatures fluctuate by about 14°C between overnight lows and afternoon highs. The sharpest temperature change occurs between August and September, with a 3°C shift in average temperatures.

Harrismith is a relatively dry area, receiving approximately 727mm of precipitation annually, which averages out to around 61mm per month. The wettest month is December, averaging 143mm of rainfall. January and February also tend to see above-average precipitation. The driest month is June, with just 9mm. That's 134mm less than December, 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. Light snowfall can occur between September and October, totalling around 6cm annually. September is the snowiest month with approximately 3cm.

Harrismith is moderately windy, 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 September, averaging 23km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in May, with average winds dropping to 17km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 6km/h between the calmest and windiest months.

It is currently autumn in Harrismith, which began on March 20, 2026. Harrismith 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 December at around 26°C, while the coldest stretch bottoms out in July near 2°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Harrismith is during March, April, September, October and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 61mm per month. By contrast, December can be uncomfortably hot with highs reaching 26°C, while July is the coldest period with lows dropping to 2°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Harrismith 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. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. 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.