Earthquakes in Tonga — May 2026

20 earthquakes were recorded in Tonga during May 2026, an average of 0.6 per day.

20 reached magnitude 4 or above and 7 reached magnitude 5 or above. The average focal depth was 192 km.

The month's largest event in Tonga was a magnitude 5.7 earthquake near Houma, Tonga on 12 May 2026 at 21:19 UTC. A magnitude 5.7 earthquake radiates roughly 5,351 tons of TNT equivalent in seismic energy.

That is close to the Tonga monthly average of 18 events over the period we cover, and level with the 20 recorded the previous month.

25% of events here are shallow (under 70 km), 65% intermediate (70–300 km) and 10% deep-focus (over 300 km). That proportion of deep-focus events is the signature of a subduction zone: only a cold slab descending into the mantle stays brittle enough to rupture at those depths.

By band, the catalogue holds 13 in the magnitude 4 range, 7 in the magnitude 5 range.

Activity peaked on 12 May, when 2 events were recorded.

The month's largest events were M5.7 near Houma, Tonga on 12 May at 154 km; M5.4 near Neiafu, Tonga on 26 May at 10 km; M5.3 near Hihifo, Tonga on 10 May at 10 km.

That is close to the 18 events Tonga averages per month across the 21 months on record.