Here there is a summary of the activity of Volcán de Colima divided into periods. The historical activity is important to study since it can indicate what is possible in the future. Currently the activity is showing a tendency to increase. Concern exists since there is evidence of an approximate 100 year cycle which terminates in a large Plinian eruption. The last occurred in 1913.
Here we can see two photos taken during the period of explosive activity prior to 1913. The question remains to whether the current phase of activity is similar to that prior to the 1913 Plinian event.