Katla in Iceland is one of the famous volcanoes of the world for the ferocity of the eruptions and associated j?kulhlaups. The major potential hazards are the j?kulhlaup floods that can hit three different floodplains, an associated tsunami that can harass the south coast of Iceland and a volcanic ash cloud that endangers civil aviation on an unknown scale. The eruption probabilities in Katla and the two others known eruption sectors of the Myrdalsj?kull glacier are reassessed and a 2013 risk curve for the next eruption in Katla is found. The probability of tsunami heights is estimated and the risk from other tsunami sources in the Atlantic Ocean is included. For the danger to aviation, two classes of eruption are defined: an EYF (EYjaFjallaj?kull) eruption class that does not produce volcanic plumes that are dangerous for air traffic in Europe, and another stronger class, the KAT (KATla) class, producing plumes that most likely are dangerous for air traffic in Europe. Overall probabilities for an EYF class eruption in next year and a KAT class eruption in the next 5 years are estimated.