 The deadliest and most damaging system was Severe Tropical Cyclone Namu, which caused over 100 deaths, when it impacted the Solomon Islands during May 1986.Of the 57 known tropical systems that have been recorded during the off-season, a total of 33 tropical cyclones have been recorded in May or have persisted into the off-season after developing in April.A total of 18 tropical cyclones have developed during October, while three systems have been recorded in both June and July, while two have been recorded in September.