The Stromboli volcano is well known for its persistent explosive activity. On July 3rd and August 28th 2019, two paroxysmal explosions occurred, generating an eruptive column that quickly rose up to 5 km above sea level. For the first eruption, the Toulouse Volcanic Ash Advisory Center (VAAC) issued a volcanic ash advisory to the civil aviation users with a two-hour delay. The various processes of these events were monitored in the near and far fields by infrasonic arrays up to distance of 3700 km and by the Italian national seismic network at a range of hundreds of kilometres. Using state-of-the-art propagation modelling, we identify the various seismic and infrasound phases for precise timing of the eruptions. We highlight the advantage of a dense seismo-acoustic network to enhance the monitoring capability of a global network at a regional scale for providing both a reliable source characterisation and a timely early warning to VAACs.