Earthquakes in Tonga — August 2026

12 earthquakes were recorded in Tonga during August 2026, an average of 0.4 per day.

12 reached magnitude 4 or above and 1 reached magnitude 5 or above. The average focal depth was 189 km.

The month's largest event in Tonga was a magnitude 5.3 earthquake near ‘Ohonua, Tonga on 02 August 2026 at 10:34 UTC. A magnitude 5.3 earthquake radiates roughly 1,344 tons of TNT equivalent in seismic energy.

That is below the Tonga monthly average of 18 events over the period we cover — a comparatively quiet month, and down from the 20 recorded the previous month.

33% of events here are shallow (under 70 km), 50% intermediate (70–300 km) and 17% 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 11 in the magnitude 4 range, 1 in the magnitude 5 range.

Activity peaked on 19 August, when 2 events were recorded.

The month's largest events were M5.3 near ‘Ohonua, Tonga on 02 August at 10 km; M4.9 near Hihifo, Tonga on 10 August at 10 km; M4.7 near Hihifo, Tonga on 19 August at 10 km.

That is 35% below the 18 events Tonga averages per month across the 21 months on record.