East African rainfall

East Africa refers to the region 5°N to 15°S and east of 30°E, mainly incorporating the countries Uganda, Kenya, Tanzania, Malawi and parts of Zambia and Mozambique. Rainfall occurs in two wet seasons - in March to May and October to December. Our forecast is for the latter period. Forecasts of the most likely of five rainfall categories (very wet, wet, average, dry or very dry) are produced using a combination of dynamical forecast models and statistical predictions. Each of these categories has occurred in one-fifth of past years.

Important

  • Long-range forecasts are unlike weather forecasts for the next few days
  • Forecasts show the likelihood of a range of possible outcomes
  • The most likely outcome in the forecast will not always happen
  • Forecasts are for average conditions over a wide region and time period
  • For more details on interpretation, see How to use our long-range predictions

Forecast

The forecast for the October to December 2013 season is that a near average or slightly drier than average season is likely for most of the region; for more details see Forecast of OND2013 East African rainfall our latest forecast (PDF, 546 kB)  .

Verification

The forecast for the October-December 2012 was for rainfall in the 'wet' category. The observed rainfall was in the 'wet' category. For a detailed look at the 2012 prediction, see   East Africa forecast 2012 East Africa OND 2012 forecast (PDF, 447 kB)

The table below compares observed outcomes with our past forecasts. Overall, the correlation between the predicted and observed category is 0.56, which is significantly skilful at the 95% level of statistical confidence.

YearForecast categoryObserved category
1994Very WetAverage
1995DryDry
1996AverageVery Dry
1997WetVery Wet
1998Dry or AverageVery Dry
1999DryDry
2000AverageAverage
2001Dry or very DryVery Dry
2002DryWet
2003DryDry
2004DryWet
2005DryVery Dry
2006WetVery Wet
2007DryDry
2008Dry or AverageDry
2009Wet or AverageWet
2010DryDry
2011AverageVery Wet

2012

Wet

Wet

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Last updated: 30 April 2014