Share This Article
The South African Weather Service has confirmed El Niño conditions into 2027, but the Western Cape is a winter-rainfall region. We spoke to climate specialist Dr Tara Southey and viticulturist Marko Roux about what the season could mean for Cape vineyards, and where preparation matters most.
National headlines are warning of a hot, dry summer as El Niño takes hold into 2027. For Cape wine farms, the picture is more nuanced. El Niño’s strongest rainfall effects are felt in South Africa’s summer-rainfall regions, while the Western Cape receives most of its rain in winter. The real questions for growers are about heat, vine water demand and how much water is available as the season begins.
El Niño develops when surface waters across the central and eastern tropical Pacific become unusually warm, altering atmospheric circulation and weather patterns. It occurs every two to seven years, and its most recent significant impact on Southern Africa was during 2023 and into 2024. This time, the signal is strong. The South African Weather Service has confirmed El Niño conditions for this year and into next, with below-normal rainfall indicated across many of South Africa’s summer-rainfall areas.
At a Western Cape provincial briefing on Thursday, 27 August, Premier Alan Winde and MEC Anton Bredell urged residents and municipalities to prepare early for summer, with Winde repeatedly describing the warnings as ‘a definite call to action’. Dam levels were around 5% lower than a year ago, while more than R65 million has been allocated to water resilience and groundwater response programmes.
What does El Niño mean for the Western Cape?
‘We need to be careful not to apply a national “hot and dry” narrative directly to the wine regions,’ says Dr Tara Southey, founder and CEO of TerraClim, which processes data from more than 1 500 weather stations nationally.
Instead, Southey points to the interaction between temperature, evapotranspiration (the combined process of water moving from the land and plants into the atmosphere), vine water demand, and available water as farms move into summer.
A vine doesn’t reset between seasons
Significant rainfall and flooding in May were followed by much drier conditions later in winter, making the sequence of events as important as any single rainfall figure. ‘It is always important to examine the compound effect of the previous season, especially in the South African wine industry, when considering the physiology of a grapevine,’ Southey says. A vine does not reset when one season ends. Heat, water stress and other conditions can influence carbohydrate reserves, bud fertility and production in the season that follows.
Southey suggests looking backwards, too. What happened last summer? What followed during autumn and winter? How much winter chill accumulated? And how is the season developing as spring growth begins? Together, these conditions help show how prepared a vineyard may be for the months ahead.
‘A long-term pattern is difficult to predict, but you can plan for it,’ Southey says. ‘The more difficult problem is variability between seasons.’ That variability complicates decisions around cultivar, clone, rootstock, irrigation and site for vines that may remain productive for decades.
Plan by the block, not the farm
Slope, elevation, aspect, solar exposure, soil depth and row orientation can create markedly different growing conditions within a single property. Therefore, the vineyard block, rather than the farm average, may be the more useful unit for planning.
In an extreme season, those differences can become apparent quickly. Water availability is the starting point, followed by heat exposure and the vineyard’s capacity to withstand stress. Soil conditions, rootstock, vigour, vine age and stress carried over from the previous season all contribute.
Southey recommends ranking blocks according to vulnerability, including shallow soils, high heat exposure and their ability to tolerate stress, and directing resources where they are most needed.
You can ease off water-saving, but not catch up
‘Should the conditions improve later in the season, a farmer can always back down on water-scarce practices, but it does not work the other way around,’ says independent viticulturist Marko Roux. This means preserving soil moisture, limiting weed competition, managing cover crops earlier on marginal sites and understanding the effective root depth of individual blocks.
Roux identifies over-irrigation on shallow soils as a common source of wasted water in the Western Cape. Soil moisture probes can show how deeply and evenly irrigation water is moving, but Roux cautions against relying on data alone. ‘Effective vineyard irrigation during drought does not happen from an office desk by means of mathematical calculations,’ says Roux. ‘Measurements need to be combined with regular visual assessment in the vineyard,’ he adds. Where water becomes limited, Roux recommends allocating it strategically around critical stages of vine development, particularly flowering and véraison, rather than applying the same irrigation approach throughout the season.
November canopy decisions, January heat
Some preparations need to happen well before the heat arrives. As Southey points out, a canopy decision made in November can determine how exposed bunches are during a January heat event.
In dry, warm vintages, Roux says lower vigour can leave fruit more exposed, increasing the risk of sunburn, faster acidity loss and overly ripe, denser fruit flavours, with less freshness and finesse. He advises making canopy decisions earlier and more conservatively. Early suckering and shoot removal can reduce the need for intervention later, while aggressive late topping and heavy leaf removal should be avoided. Instead, Roux favours well-aerated canopies that retain greater protection around bunches.
Roux has also seen winemakers and viticulturists become more precise about picking dates as they seek freshness, balance and lower alcohol levels in hotter or more erratic seasons. But earlier harvesting is not a universal solution. He says Chenin Blanc, Chardonnay to some extent, Syrah and increasingly Pinotage can offer more flexibility for earlier picking. At the same time, certain Bordeaux varieties can be more difficult to harvest early under South African conditions. Representative sampling and regular grape tasting therefore remain important when adjusting picking dates.
Preparing for a longer window of fire risk
The concern follows an unusually severe 2025/26 fire season, when significant fire activity began as early as September 2025. Looking ahead, the Western Cape is now preparing for an eight-month high-risk fire period, stretching from October through May.
Southey says several changes are happening at once: more hot days, fewer cold days, longer gaps between meaningful rainfall, and greater variability in wind and drying conditions. Together, these can cause vegetation to dry earlier and remain dry for longer.
Roux, who consulted two producers on mountainous properties for practical input on fire preparedness, says farms should look beyond firebreaks alone. Access roads and turning areas should be checked, particularly following May’s flooding, while staff need to understand the property’s fire plan and water refill points need to accommodate firefighting equipment.
He also recommends regularly checking for less obvious fuel loads, from stacked wood and dry weeds to leaves accumulating in gutters. Vineyards do not need to be kept bare, he says, but dry weeds and cover crops should be kept short enough to reduce the risk of rapid fire spread. Roux also advises farms to belong to their local Fire Protection Association, even where this is not an insurance requirement.
Farms should also make financial arrangements for emergency aerial support in advance, particularly for weekends or holidays when arranging payments at short notice may be difficult.
Our earlier article on wildfire preparedness explores training, alien vegetation clearing, inter-estate communication, smoke-taint management and ways to support the Volunteer Wildfire Services.
Resilience is built before the difficult season
While old vines are often associated with resilience in difficult seasons, Roux cautions against assuming that age alone determines how a vineyard will cope. Well-managed old dryland vineyards can perform well in hot, dry conditions, but so can younger irrigated vineyards when water, crop load and vine health are managed appropriately.
For the season ahead, Roux’s advice is pragmatic. ‘Take stock of the water actually available now and develop several scenarios, from severe to moderate,’ he says. Knowing the effective root depth of individual vineyards, Roux argues, will allow producers to make more calculated irrigation decisions if conditions tighten later in the season. That longer-term principle also applies to climate data. ‘Better data does not necessarily mean making more decisions,’ Southey says. ‘Often it means making the important decisions earlier.’ For Western Cape wine farms, that may be the most useful way to interpret the El Niño headlines.
The precise conditions of the coming months will continue to unfold. What producers can know now is where their water position stands, which vineyard blocks are most exposed and where intervention will matter most. In a season defined as much by variability as by heat, preparedness does not depend on knowing exactly what summer will bring; it depends on knowing where the risks lie before the season exposes it.