In graphs: we chart Cape Town’s rainfall in May, June and July 2018

May has come, and July has gone. And just like that, winter is nearly over in Cape Town. In a few months’ time, it’ll be spring and we’ll all be hearing that term we love so dearly: “Day Zero”.

Thankfully, according to data from the City of Cape Town, May and June were extremely wet months across Cape Town and may just be enough to ward off those two scary words.

Looking at six weather stations in particular dotted around the metropol; namely Newlands, Steenbras, Table Mountain’s Woodhead, Theewaterskloof, Voëlvlei and Wemmershoek; we visualised just how much rain the city has received over the winter months.

Cape Town rainfall: May 2018

In May, most of the precipitation fell in the final week of the month, so the graphs look completely different before 21 May.

Nevertheless, the long-term average was bested by some 90mm thank to the deluge experienced in the final few days. Notably, the Wemmershoek catchment area received more than 90mm in excess of its long term average. Newlands was also notably wet in May, receiving just over 27cm of rain in total.

Other areas struggled though. The Steenbras catchment was decidedly dry, receiving just below 80mm of its usual 127mm for the month.

Cape Town rainfall: June 2018

June was also a dry month for Cape Town’s closest dam. Just 121mm of rain fell across the Steenbras reservoirs, some 30mm less than what it usually receives in June. But, overall, June was an extremely damp month.

The Theewaterskloof Dam began its recovery, meeting its long-term average of 71mm.

However, three areas stood out: Table Mountain’s Woodhead reservoir received over 270mm of rain, Newlands received more than 360mm, and the Wemmershoek Dam bested its long-term average by some 100mm.

Overall, the six areas received more than a metre of rainfall in total. That’s a combined 1315mm.

Cape Town rainfall: July 2018

After two bountiful months, July massively missed its long-term average.

Of the six surveyed areas, none saw their usual complement of precipitation. In fact, just 52% of the long term average fell within the mentioned areas. That’s 502mm as opposed to 968mm.

The biggest worry was Newlands. Just 116.5mm fell in the area during the month, this of the usual 271.5mm experienced. That’s also less than a third of the rainfall that fell in Newlands through June.

Despite this, dams continued to fill.

The Theewaterskloof Dam continued its remarkable recovery to finish July at 42% full. The Wemmershoek Dam, which received 110.6mm in July, jumped to 84%. And the Voëlvlei Dam, which received just 10mm short of its monthly average, filled to around 58%.

At the end of July, Cape Town’s dams were around 58% full in total.

More detailed graphs of each month can be viewed below.

Note: the actual rainfall that fell during each month is represented for the six aforementioned dams, across the months of May, June and July in the left hand side graphs. The long-term average — the amount of precipitation usually experienced based on historical data — is represented on the right hand side.

August and beyond

The winter months may be over, but winter in Cape Town is anything but. Judging by the long-term averages, the city should receive rainfall throughout the month.

Here’s what August usually brings to the city, according to the City of Cape Town:

• Newlands: 243.6mm
• Steenbras: 123.3mm
• Woodhead/Table Mountain: 213.5mm
• Theewaterskloof: 76.7mm
• Voëlvlei: 82.9mm
• Wemmershoek: 154.5mm

The City of Cape Town in July stressed that another dry month in August could spell the continuation of water restrictions.

“Due to the lack of rainfall over the past two weeks [at the beginning of July] and the lower prospects over the coming weeks, it was decided that it was not appropriate to relax restrictions yet. The situation will again be assessed in August,” wrote deputy mayor Ian Neilson in a press release.

Rainfall is expected in Cape Town on Tuesday, but as for the rest of the month, that remains to be seen.

For a more in depth look at Cape Town’s rainfall month-by-month, season-by-season for the past 40 years, visit UCT’s CSAG resource here.

Feature image: Max Bender via Unsplash