Earthquakes in Puerto Rico — October 2025

131 earthquakes were recorded in Puerto Rico during October 2025, an average of 4.2 per day.

2 reached magnitude 4 or above and 0 reached magnitude 5 or above. The average focal depth was 19 km.

The month's largest event in Puerto Rico was a magnitude 4.0 earthquake near Culebra, Puerto Rico on 21 October 2025 at 07:39 UTC. A magnitude 4.0 earthquake radiates roughly 15 tons of TNT equivalent in seismic energy.

That is close to the Puerto Rico monthly average of 173 events over the period we cover, and up from the 130 recorded the previous month.

96% of events here are shallow (under 70 km), 4% intermediate (70–300 km) and 0% deep-focus (over 300 km). Almost everything here is crustal. That is characteristic of transform faulting or continental deformation rather than subduction — and it means shaking at the surface is strong for the magnitudes involved.

By band, the catalogue holds 8 in the magnitude 1 range, 95 in the magnitude 2 range, 26 in the magnitude 3 range, 2 in the magnitude 4 range.

Activity peaked on 07 October, when 17 events were recorded.

The month's largest events were M4.0 near Culebra, Puerto Rico on 21 October at 73 km; M4.0 near Guánica, Puerto Rico on 07 October at 12 km; M3.7 near Guánica, Puerto Rico on 07 October at 23 km.

That is 24% below the 173 events Puerto Rico averages per month across the 21 months on record.