By Joseph D’Aleo, CC
El Ninos always produce a global pop in temperatures. So expect that this next 6 months or so even in the only accurate data, from satellites. Strong El Ninos usually are followed by a pendulum like strong La Nina with a cooling. Major volcanoes can override or diminish any warming as El Chicon and Mt. St. Helens did in the early to mid 1980s and Pinatubo/Cerro Hudson did in the early to mid 1990s.
That said, there are many active volcanos around the world and many more unrestful which could erupt. There seems to be more active volcanos when the sun is quiet, but I cannot find any specific studies. Here is a link to a list of active and unrestful volcanos: http://www.volcanodiscovery.com/erupting_volcanoes.html
Joe D’Aleo quotes Russian and Australian scientist supporting the view that we are in for some prolonged cooling following the El Niño, you can read rest on his blog post HERE.
Some updated graphics to support the comment discussion (07-17-15):