OPEC crude output rose sharply in June, according to a Bloomberg survey, with shipments through the Strait of Hormuz climbing over the same month.

The survey, compiled from tanker-tracking data, producer statements, and estimates from consultants and analysts, marks the latest reading of the producer group's supply trajectory as it continues to unwind earlier production curbs. Bloomberg's monthly OPEC survey is a widely used benchmark for tracking output from the group's members before official figures arrive.

What does the survey show?

June output increased across the OPEC member base surveyed by Bloomberg. The rise comes as several producers within the group, led by Saudi Arabia and including the UAE and Iraq, continue to restore barrels they withheld under the voluntary cuts that began in 2023. These eight producers have been phasing out reductions in successive monthly increments throughout 2025.

The survey also registered a jump in crude flows through the Strait of Hormuz, the chokepoint that handles roughly a fifth of global oil trade and serves as the export gateway for most Gulf producers, including Saudi Arabia, Iraq, the UAE, Kuwait, Iran, and Qatar. Higher Hormuz traffic in June indicates that the additional barrels OPEC members brought on reached the water rather than sitting in domestic storage.

Why does the timing matter?

The June increase lands amid continued debate over how quickly OPEC and its allies should return withheld supply. In recent months, the group has accelerated the pace of unwinding, a decision that has drawn analysts' attention for its potential to weigh on balances.

Price commentary following the survey has attributed significance to the supply build. Analysts cited by Bloomberg treat the upward output trend as a factor pressuring crude benchmarks, with the market already absorbing successive monthly additions.

The higher Hormuz flows also carry a geopolitical dimension, however measured the read: the chokepoint remains a focal point for risk premium in crude pricing, and increased traffic there concentrates more of the world's exported barrels through a single corridor.

Sanctioned supply versus appraisal-stage speculation

Bloomberg's survey covers actual production and observed shipments — barrels on the water, not forecasts. It is separate from OPEC's own monthly report and from the International Energy Agency's balances, both of which arrive later in the month and may refine the numbers.

Readers should distinguish:

• Surveyed June output: Bloomberg's estimate of what OPEC members actually produced and loaded.
• OPEC secondary-source figures: the group's own survey-based numbers, used to set compliance baselines.
• Direct-communication figures: what member states themselves report, which frequently differ from secondary sources.

The Bloomberg survey typically previews the secondary-source data that will appear in OPEC's monthly report, giving traders an early read on supply before the official release.

What to watch next

The watch items from here: OPEC+'s next output decision for August, expected at the group's upcoming meeting; the OPEC monthly report, which will confirm or revise the June survey estimates; and continued tanker-tracking evidence on whether Hormuz throughput keeps pace with the production increase. The margin question is whether demand absorbs the returning barrels through the second half, or whether the surplus builds.

This story is based on a Bloomberg survey of OPEC June output; figures cited here reflect that survey's scope. Consult Bloomberg's full report for the complete country-by-country breakdown.