Recorded ship transits through the Strait of Hormuz are running 96% below their 2025 average

Traffic fell by more than nine-tenths in a week and has not come back

The IMF's PortWatch service counts daily transits through the world's main shipping chokepoints using vessel position signals picked up by satellite.¹² For the Strait of Hormuz it recorded an average of 85.5 transits a day across 2025, with monthly averages ranging from 55.5 in December to 103.0 in May.¹ From 1 January to 27 February 2026, the day before the strikes began, it averaged 68.1.

US and Israeli strikes on Iran began on 28 February, and on 2 March the Islamic Revolutionary Guard Corps announced that the strait was closed.⁴ PortWatch recorded 57 transits on 28 February and 20 on 1 March. In the week from 2 to 8 March the daily average was 2.6.¹

Since 1 March PortWatch has recorded 1,404 transits in 218 days, an average of 6.4 a day. At the 2025 rate, the same period would have seen about 18,650. On 13 of those days it recorded none at all.¹

Every month since March has averaged fewer than 13 ships a day

March averaged 3.2 transits a day. Al Jazeera reported that a ceasefire in April, accompanied by a US naval blockade of Iranian ports, left traffic at about five vessels a day, which matches the PortWatch series: April averaged 7.1 and May 3.9.⁴¹

The two higher months, June and July, reflect a single interruption to the closure rather than a recovery that has held.

An interim deal lifted traffic to about a quarter of normal, for 27 days

Reuters reported that the US and Iran signed an interim agreement on 17 June and that the US lifted its blockade of Iranian ports the following day.⁵ Under Iran's terms, ships needed a passage permit from a new Iranian strait authority and had to coordinate with the Revolutionary Guards navy, according to the same report.⁵

Between 17 June and 13 July PortWatch recorded an average of 20.4 transits a day, peaking at 51 on 24 June, the highest daily count since the closure began.¹ Al Jazeera reported that the US resumed its blockade on 14 July and that traffic fell back to about five a day.⁴ From 14 July to 4 October the PortWatch average was 4.3.

Recorded tanker crossings have fallen furthest

PortWatch splits its counts by vessel type. In 2025 tankers made up 56% of recorded transits, an average of 48.2 a day. In September 2026 the strait recorded 1.1 tanker transits a day, a fall of 98%. Other vessel types, including container ships and bulk carriers, fell from 37.4 a day to 2.5, a drop of 93%.¹

Tankers accounted for 31% of the transits recorded in September and 40% of all those recorded since 1 March. That sits awkwardly with reporting that most of the ships still crossing are tankers.⁴ One reading, which the data cannot confirm, is that a larger share of tanker traffic than of other traffic is crossing with transponders switched off and so is missing from the count.

The choice of baseline matters less than it might. Traffic in 2025 was itself uneven, so the piece uses the full-year average rather than a single month. Comparing September 2026 with September 2025, when 87.9 ships a day crossed, gives a fall of 96%; comparing it with the weeks just before the strikes gives 95%.¹

A fifth of the world's oil normally passes this way

The US Energy Information Administration estimates that about 20 million barrels of oil a day moved through the strait in 2024, equal to roughly a fifth of global petroleum liquids consumption, along with around a fifth of global trade in liquefied natural gas.³ It found that 84% of the crude oil and condensate passing through went to Asian markets.³

Transit counts measure ships, not cargo, so the PortWatch series does not show how much oil or gas is still moving. Al Jazeera reported that most of the remaining transits are tankers under naval escort or sailing with tracking switched off, and that oil prices peaked above $130 a barrel in April.⁴