Recent studies suggested that transient and long-term stress changes caused by Earth's surface processes (e.g., extreme weather events, annual variations on groundwater storages) can affect earthquake activities in the subsurface. However, these studies may be limited by the completeness of standard earthquake catalogs, especially during or right after extreme weather events. Here we apply the template matching method to build a more complete earthquake catalog in Taiwan spanning seven months before and 12 months after 2009 typhoon Morakot, which brought the highest rainfall in southern Taiwan in the past 60 years and triggered numerous landslides. We then use the enhanced catalog to investigate possible influences of typhoon-driven Earth's surface processes (atmospheric pressure, precipitation, and erosion) on local seismicity. We find that the seismicity rate of a 40-day earthquake sequence in northeastern Taiwan was reduced significantly right after the passage of typhoon Morakot's eye center. In the typhoon-triggered landslide zone in southern Taiwan, we find a slight increase in background seismicity rate in the next year after Morakot, matching the results of a recent study. However, we do not observe a clear change in the Gutenberg-Richter b-value in this zone, which is different from the recent study. Station outages during and right after Morakot prevents us from better understanding short-term precipitation effect on local seismicity. Overall, except for a reduction in seismicity rate near the typhoon's low-pressure eye center in northeastern Taiwan, we do not observe other clear seismicity changes that can be attributed to surface changes induced by typhoon Morakot. Plain Language Summary It is important to study cascading nature hazards (typhoons/hurricanes, landslides, earthquakes, etc.) because of their threats to human life and property. 2009 typhoon Morakot is the deadliest typhoon in Taiwan, which brought the highest rainfall in the past 60 years and led to numerous landslides. To investigate the possible influences of Morakot on subsurface earthquake activities, we build a more complete earthquake catalog for Taiwan spanning seven months before and 12 months after 2009 typhoon Morakot. This enhanced earthquake catalog includes many small earthquakes that cannot be felt by local residents in their ordinary life and were not in the standard earthquake catalog. In northeastern Taiwan, our results show that a 40-day earthquake sequence was apparently shut down right after the passage of typhoon Morakot. If this observation is not a pure coincidence, it may suggest that the low-pressure system of typhoon Morakot was capable of modulating the subsurface seismicity behavior. In southern Taiwan, the heavy-rainfall and landslide region, we do not observe clear seismicity changes that can be attributed to surface changes induced by typhoon Morakot.