Popocatepetl is one of the most violent volcanoes in Mexico, having had more than 15 major eruptions since the arrival of the Spanish in 1519.
A major eruption occurred in 1947.
On December 21, 1994, the volcano spewed gas and ash which was carried as far as 25 km (16 mi) away by prevailing winds. The activity prompted the evacuation of nearby towns and scientists to begin monitoring for an eruption.
In December 2000, tens of thousands of people were evacuated by the government based on the warnings of scientists. The volcano then made its largest display in 1,200 years.
On December 25, 2005, the volcano's crater produced an explosion which ejected a large column of smoke and ash about 3 km (1.9 mi) into the atmosphere and expulsion of lava.
In January and February of 2012, scientists have been noticing Popocatepetl's action increasing.
On January 25, 2012, an ash explosion occurred on the mountain causing much dust and ash to contaminate the atmosphere around it.
On April 19, 2012 there were reports of superheated rock fragments being hurled into the air by the volcano. Ash and water vapor plumes were reported 15 times over 24 hours.