El Niño in the Pacific always hampers hurricane activity in the Atlantic
A study by Texas University found it can sometimes reduce it by 50%
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/el-ni%C3%B1o-causing-see-saw-weather-fewer-hurricanes-formed-atlantic-year-pacific-was-hotbed-storms
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/daily-mail-united-kingdom
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/el-nino
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/atmosphere
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hurricanes
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/atmosphere-and-ozone-layer