Strait of Hormuz traffic slumps as U.S.-Iran tensions persist
Ship crossings through the Strait of Hormuz remained critically low over the weekend, with fewer than 20 commodity vessels transiting the waterway, according to initial data from shiptracker Kpler cited by Reuters. Four vessels crossed on Sunday, August 23, 2026, and 13 on Saturday, August 22, 2026, compared with 16 on Friday. The figures could change because some ships had switched off their transponders.
The United Kingdom Maritime Trade Operations (UKMTO) reported that over the week to August 21, a total of 103 vessels entered the strait and 89 exited. The agency said traffic remains well below normal levels, with AIS-detected transits approximately 90% below pre-conflict baselines and declining since a peak between June 24 and June 26. Tanker traffic made up 45% of the total, with oil tankers accounting for 56% of those.
The low numbers follow a period of heavy disruption. The U.S. and Israel launched a military operation against Iran on February 28, according to TASS. A memorandum of understanding on cessation of hostilities was signed in June, but on the night of July 8 the U.S. resumed large-scale strikes on Iran, accusing Tehran of violating agreements concerning the strait. Since July 6, the UKMTO has recorded 23 incidents of projectile strikes causing bridge, engine-room, and structural damage to vessels in the area.
The Wall Street Journal previously reported, citing satellite data, that an average of 26 vessels passed through the strait daily in July — five times fewer than before the conflict began.
Threats escalate, but oil starts week lower
U.S. Treasury Secretary Scott Bessent threatened on Sunday, August 23, what he called "an economic D-Day" against Iran in an op-ed for the Financial Times, saying the U.S. is entering the "endgame" and warning of a "single greatest financial offensive ever marshalled against an adversary."
In response, Mohsen Rezaei, secretary of Iran's Supreme National Security Council, wrote on social media that if the economic war continues, "not a single drop of oil will be exported, neither through the Strait of Hormuz nor from anywhere in the Persian Gulf."
Despite the exchange, oil prices started the week lower, according to OilPrice.com, as markets anticipated the U.S. pressure campaign.
Refined fuel markets show the real strain
The crude oil market is focused on a "wrong debate" over how much crude is actually flowing through the strait, according to a column in The Economic Times. U.S. Energy Secretary Chris Wright has repeatedly claimed that far more crude is passing through than vessel-tracking analysts such as Kpler can detect — he cited about 15 million barrels per day (bpd) on one day last week, and an average of about 9 million bpd over a seven-day period, without providing vessel names or destinations.
Vessel monitoring services estimate around 5 million bpd is leaving the strait, including dark transits and ship-to-ship transfers. But the more telling signal, the column argues, is in Asia's refined fuel imports: Kpler data shows Asia's imports of light and middle distillates — diesel, jet fuel, and gasoline — are estimated at 5.59 million bpd in August, down 21% from the 7.08 million bpd average in the three months to the end of February.
Indonesia's imports are estimated at 432,000 bpd, the lowest in 13 months, down from 533,000 bpd before the conflict. The Philippines is expected to see 257,000 bpd, versus 362,000 bpd earlier. Australia's imports are nearly unchanged at 863,000 bpd against 880,000 bpd previously.
Refining margins reflect the tightness. The gasoil margin at a Singapore refinery stood at $71.29 a barrel on August 21, down from a record $85.63 on March 30 but still 226% higher than the $21.90 on February 27. Gasoline margins ended at $20.74 a barrel, up 159% from $8.00 on February 27.
Traffic details from the weekend
Kpler data detailed the weekend's movements: on Friday, August 21, two empty very large crude carriers (VLCCs) entered the Gulf with transponders off, one heading to Iraq and the other to Bahrain. A VLCC carrying 2 million barrels of Emirati crude exited the strait on Thursday. Eight very large gas carriers transited over the past three days, six entering empty and two carrying LPG loaded from Iran.
At the Bab el-Mandeb strait on the other side of the Arabian Peninsula, 24 commodity vessels sailed through on Sunday, down from 32 on Saturday but up from 22 on Friday, according to Kpler data. Two VLCCs entered the Red Sea on Saturday — one carrying Iraqi Basrah crude and the other empty.
Earlier week showed similar weakness
Earlier data from the week of August 15-17 showed the same pattern. On Monday, August 17, six commodity ships transited the strait — three exiting, three entering — compared with a 10-day average of 11, according to The Hindu. Three ships crossed on Saturday and two on Sunday. No VLCCs or LNG tankers passed through. A very large gas carrier, the Xavia, entered via the Iranian route under ballast.
At Bab el-Mandeb, 19 commodity vessels transited on Monday, below the 10-day average of 26 and Sunday's 33. Of those, five were entering the Red Sea and 14 exiting, including the VLCC Norns laden with 2 million barrels of oil. Two liquid tankers, Admiral and Portofino, were entering, with Portofino carrying diesel for markets west of Suez.
The persistent low traffic comes amid a stalemate in U.S.-Iranian peace talks, according to The Hindu. The UKMTO report for the week to August 21 noted vessels aborting transit plans or switching to the strait's northern route after attacks.
Brent crude futures with October delivery rose above $94 a barrel on August 21 for the first time since July 24, according to trading data cited by TASS.