Zimbabwe Absurdity

We live in the sub-tropics and experience a climate modified by altitude so rarely get very cold winters. They tend to be dry and dusty – the rains come from mid-November to March. While snow very occasionally occurs in Zimbabwe and is worth a photo opportunity frost is not at all uncommon, especially on the central watershed, but this year it has been rare. It has been a very mild winter so far with some daytime maxima reaching 28⁰C and nighttime minima of 7 or more. So far there have been no overcast and cold days caused by cold fronts that come up from the Antarctic. What is going on and what does it mean for the rainy season?

Droughts are endemic to southern Africa and are most likely when an el Nino event appears off the Ecuador coast. This is a warm current and has a global effect on the weather; for us it’s drought. Usually.

The phenomenon is known as the el Nino Southern Oscillation (ENSO) and is recorded by the Columbia University in the USA.

A cooling of the sea surface is known as a la Nina and in this part of the world is characterised by wetter than normal years. The chart above indicates that the last three years have been wetter than normal though Harare did not experience this – in fact rainfall records at my business showed lower than average rainfall whereas other parts of the country did indeed experience a wetter than average summer. The memorable drought of 1992 is evident in that season’s el Nino event.

This el Nino event very likely means a drought for the coming summer. Harare, where I live, is increasingly dependent on boreholes to supply domestic water and over the years the average depth at which water can be found has steadily increased as water is extracted. With all the ongoing construction within the city area more and more water runs off into the streams and the ground water is replenished less. A drier then usual season is not good news.

Two years ago we took the plunge and had a deeper borehole drilled on our premises. We were lucky and found water. Though not in large quantity it has been sufficient for our needs since then. How it will be affected by what promises to be a dry few years remains to be seen. My commercial seedling nursery will be affected likewise. We wait in trepidation.