Earthquakes in Puerto Rico — September 2026

70 earthquakes were recorded in Puerto Rico during September 2026, an average of 2.3 per day.

0 reached magnitude 4 or above and 0 reached magnitude 5 or above. The average focal depth was 22 km.

The month's largest event in Puerto Rico was a magnitude 3.8 earthquake near Culebra, Puerto Rico on 11 September 2026 at 08:12 UTC. A magnitude 3.8 earthquake radiates roughly 6.4 tons of TNT equivalent in seismic energy.

That is below the Puerto Rico monthly average of 170 events over the period we cover — a comparatively quiet month, and down from the 158 recorded the previous month.

91% of events here are shallow (under 70 km), 9% 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 3 in the magnitude 1 range, 44 in the magnitude 2 range, 23 in the magnitude 3 range.

Activity peaked on 13 September, when 14 events were recorded.

The month's largest events were M3.8 near Culebra, Puerto Rico on 11 September at 90 km; M3.7 near San Juan, Puerto Rico on 05 September at 11 km; M3.6 near Suárez, Puerto Rico on 12 September at 19 km.

That is 59% below the 170 events Puerto Rico averages per month across the 22 months on record.