Cape Town rainfall pattern.
Cape Town falls within a winter rainfall area, with June receiving the highest average rainfall of 143 mm in the month. January is the driest month, receiving a measly 24mm of rain on average. The total rainfall for Cape Town sits at 853mm per annum.
How often does it rain in Cape Town?
August has the most rainfall days with 13.7 day of rain, while February typically has the least with 4.6 days per month on average.
The rainfall pattern in the Cape Town area allows for much rainwater harvesting over the wet winter months. These wet months make it possible to store vast amount of rainwater. This stored water can be used for irrigation use over the dry summer months or to replace the municipal drinking water supply.
Should enough rainwater be harvested and stored over the wet winter months it is possible to go off-grid for several months. Over the rainy season excess water will be stored for use during the dryer months. In mid summer, depending on water use habits, some municipal water may be needed to supplement harvested rainwater. The degree to which municipal water would be needed to be supplemented will depend on the available roof area used for harvesting and the water tank storage capacity.