Iona — 2025

A tropical depression formed from a fast-moving tropical wave near 0000 UTC 27 July 2025 about 830 nautical miles southeast of Hilo, Hawaii. The system strengthened into Tropical Storm Iona later on 27 July and moved generally west-northwest across the central Pacific. Iona rapidly intensified late on 28 July into 29 July, reached its peak on 29 July, then weakened through 30 July and became a depression by 1 August, dissipating later that day before reaching the International Date Line. Iona did not make any landfalls. It remained over open water during its entire lifetime, and no coastal watches or warnings were issued. The hurricane’s maximum sustained winds peaked at 115 knots (about 132 mph) with an estimated minimum central pressure of 956 millibars on 29 July. At peak intensity Iona was a category 4 hurricane on the Saffir–Simpson scale. Because Iona stayed well offshore there were no direct storm surge measurements tied to the hurricane on land and no reported wind observations of tropical-storm force from ships or land stations. Rainfall and surge impacts were not reported for specific cities or counties in the report. There were no reports of damage or casualties associated with Iona. The Central Pacific region therefore experienced no confirmed direct or indirect fatalities tied to this storm. Noteworthy aspects include a very rapid rise and fall in intensity: the best track shows six consecutive overlapping 24-hour periods with rapid intensification noted, including a peak increase of 60 knots in 24 hours. Forecasting intensity was difficult for this storm — official intensity errors were much higher than recent averages — while track forecasts performed better than average at some lead times. No coastal impacts occurred, so the report is abbreviated.