Highlights
October to December 2015 was the driest in at least 35 years in several southern parts of the region.
Large decreases in planted area are expected in some areas, as planting windows close
Vegetation conditions improved in some central parts, though conditions remained very poor in many southern areas
Above normal rainfall was received in some western parts of the region in December, helping to reduce the overall rainfall deficits in those areas.
Seasonal forecasts are suggesting higher than usual chances that below normal rains will continue in the south
Regional Summary
In many parts of the SADC region, the October to December 2015 period has been the driest in at least the last 35 years, based on analyses of the 35-year CHIRPS historical satellite-based rainfall dataset. The areas affected include much of South Africa, Lesotho and Zimbabwe, as well as parts of Botswana, southern and central Mozambique and southern Zambia. For many areas in the southern half of the region, the October-December 2015 rainfall totals were among the 4 driest since 1981. In addition, excessive temperatures throughout the October-December period saw potential evapotranspiration (PET) rates being the highest estimated since 2001, which is as far back as the PET dataset used for the analysis goes. The situation is exacerbated by poor rainfall in many areas during the 2014/15 season, which resulted in low crop production and reduced water supply.
These metrics suggest unprecedented climatic strain is being exerted this season on water resources, crop conditions and livestock in many areas, with the consequent negative implications for food security.
During the second half of December, rainfall improved in the western areas and some north-eastern parts of the region, while rainfall deficits intensified in many central and southern areas. For the month of December overall, rainfall was well below normal in the south-western half of South Africa, Lesotho, southern Mozambique and southern Zimbabwe (brown colours, Figure 1). Rainfall was also below normal in eastern half of Angola, south-eastern half of Zambia, Malawi, central Mozambique, Zimbabwe, eastern Botswana and northern South Africa (yellow colours, Figure 1). Combined with the excessive high temperatures that resulted in very high rates of evapotranspiration, the weather conditions have resulted in very dry conditions overall that have not been conducive for crop growth in many areas. In some of the areas mentioned above, planting has not been possible due to the dry conditions. Normally by end of December planting is expected to have been completed in most parts of the region, and crop growth should be well underway. While December rainfall was low in the areas mentioned above, a few areas in the western and northern areas received good rains. The good rains received in western Angola, Namibia, western Botswana and Swaziland helped to slightly reduce, but not eliminate the moisture deficits that have been experienced in these areas since last season. Much more rainfall is required to eliminate the water deficits in these areas, as is the case in most parts of the region, which are showing overall below-average seasonal rainfall accumulations (Figure 2, yellow and brown colours), combined with higher than average evapotranspiration-related water losses due to the high temperatures, and poor rainfall in many areas in the past season. In contrast, good rainfall continued to fall in Tanzania. Northern Mozambique and parts of the DRC also received good rains in December.
The net impact of the poor rainfall and high temperatures thus far on crop production is two-fold. The first is a delay in the onset of rains and the subsequent delay in planting. Reports indicate that the delayed planting has affected several countries, including Lesotho, South Africa, Swaziland, Zambia and Zimbabwe. In some cases the delays are at least 60 days (2 months). The delays may result in reduced yields, as the seasonal cessation of rains can occur before crops have reached maturity. The large delays also result in reduced area planted, as more farmers abandon planting intentions due to the greatly reduced chances of a successful harvest.
The second major impact of the low rainfall and excessive temperature on crop production is the moisture stress and wilting experienced by crop. The soil water index, a modelled product that estimates the amount of water in the soil as a fraction of the soil’s water retention, shows that in many areas crops are potentially experiencing moisture stress or wilting . Reports indicate that in some of the areas shown in orange on Figure 3, some of the crops that were planted have permanently wilted and replanting is required.
Vegetation continued to improve slightly in some of the northern and central areas, after the moderate to good rains that were received there. Of note, improvements were noted in parts of western Namibia, south-western Angola, Zambia, Zimbabwe, Malawi and northern Mozambique. In many southern areas however, vegetation remains the lowest observed in the last 15 years, with consequently negative implications for pasture in particular. South-eastern Angola, much of Botswana, Lesotho, southern Mozambique, Namibia, South Africa, Swaziland, appear to be amongst the worst affected in terms of vegetation, according to satellite imagery. Reports indicate approximately 20,000 cattle have died in Swaziland due to effects of the drought, while in Zimbabwe over 8,000 cattle have died.
Short term forecasts through early January suggest a continuation of dry conditions over most central and southern parts of the region, except for northern South Africa, where some rainfall activity is expected. Northern parts of the region, including Tanzania, DRC and Angola, also expect good rains during this time. By mid-January, rains are expected to have improved significantly across most part of the region, except for some eastern areas where dryness has been forecast to continue. The current El Niño event remains among the 3 strongest on record, although several indicators suggest that it has reached its peak, and is expected to weaken in the near future. The El Niño event has been associated with below normal rainfall experienced across much of southern Africa this season. Seasonal forecasts for January to March 2016 indicate high chances that rainfall will be normal to below normal in the southern half of the region during this period, while normal to above-normal rains are expected in the northern parts of the region.