Marikina has the same climate as the rest of Metro Manila: hot and humid year-round, with a wet season from June to November and a drier, slightly cooler period from December to May. The best time to visit is during the dry season (November to April), when rain is less likely to disrupt a day trip and temperatures, while still warm, are more comfortable for walking.
Avoid visiting during or immediately after a major typhoon. The Marikina River has flooded badly during severe storms — Typhoon Ondoy in 2009 inundated much of the city to several metres depth — and the riverside areas and lower districts are vulnerable during heavy weather. The Marikina Valley fault system, which runs along the western edge of the city, is a seismic hazard, though this is a background concern rather than a seasonal one.
There are no events in Marikina compelling enough to specifically time a visit around, though the city holds shoe-industry festivals periodically. For most visitors, Marikina is a day trip from Manila and the timing of the visit is determined by the broader Manila itinerary rather than anything local.