Strait of Hormuz: Traffic Plunged 81% After Iran's Closure Threat, Then Recovered

The Data: Saturday Peak → Sunday Plunge → Monday Recovery

Saturday, June 20 — Traffic hit its highest levels since the war began. Kpler recorded 26 commodity ship transits , and AXSMarine reported 38 commercial vessel transits .

Sunday, June 21 — After Iran's closure announcement, traffic collapsed. Kpler recorded only 5 vessels transiting the strait, down from 26 the previous day — a 81% drop . Among those five were three Very Large Crude Carriers (VLCCs) . Windward, a maritime intelligence firm, described shipping activity as having experienced a "halt" over the weekend .

Monday, June 22 — Traffic recovered sharply. By late Monday, Kpler recorded 26 commodity ship transits, nearing previous post-agreement levels . AXSMarine reported 38 commercial vessel transits . Al-Monitor confirmed that as of 1530 GMT Monday, traffic was flowing at a faster pace than before the U.S.-Iran agreement .

Qatari LNG Carriers Cross Despite the Slowdown

Four Qatari LNG tankers — Wadi Al Sail, Mekaines, Al Sadd, and Mesaimeer — headed into the Strait of Hormuz on Monday, according to Kpler shipping data, using an Iranian-approved route for the first time since the conflict began . Kpler also reported that three Adnoc-linked LNG tankers (Umm Al Ashtan, Mraweh, and Al Hamra) signaled movement from Das Island in the UAE .

Mixed Signals Within Iran's Government

While the military command issued the closure order, other Iranian officials were simultaneously engaged in diplomatic talks in Switzerland with U.S. representatives to refine the interim agreement . The crisis timeline notes that Iran's foreign ministry separately said shipping was "operating normally," even as the IRGC declared the strait closed . The closure announcement was described as a "reaction" that cast doubt on the days-old deal, suggesting not all factions within Iran's government were aligned .

Oil Markets: Spike and Reverse

Oil prices reacted sharply to the standoff. On Friday, June 19, Brent crude for August delivery settled at $80.57 . On Saturday, June 20, Brent jumped to around $82 and WTI to $79 in perpetual futures trading . At the Monday, June 22 opening, Brent crude rose as much as 2.2%, hitting $82.30 per barrel, while WTI climbed above $78 . But later Monday, after U.S. Vice President JD Vance indicated progress in negotiations with Iran and confirmed the strait remained accessible, Brent fell by $1.19 (1.48%) to $79.38 per barrel . The initial spike was reversed as diplomatic signals calmed markets.

Key Takeaway

The strait was never physically closed by Iranian forces in a way that stopped all traffic — tracking data shows ships continued to cross. But Iran's announcement had a real chilling effect: Sunday saw a sharp 81% drop in transits from Saturday's levels as shipowners obeyed the warning, before traffic rebounded on Monday as the U.S. reassured markets and Qatar pushed LNG tankers through. Brent's spike-and-reverse ($82.30 → $79.38) reflects markets pricing in the gap between Iran's rhetoric and the reality of continued, if volatile, transits amid active U.S.-Iran diplomacy in Switzerland.