Brent crude back above $90 on August 31, 2026 — the settlement was reported as 90.49, 90.69 and 91.09
Brent crude returned above 90 dollars a barrel on August 31, 2026, immediately after US forces struck two Iranian rocket launchers on Larak Island and Iran retaliated against US bases in Jordan. The exact settlement is not settled: reports of the same session gave 90.49 dollars (+2.71 percent), 90.69 dollars (+2.93 percent) and 91.09 dollars (+3.4 percent), with West Texas Intermediate reported near 86 dollars. This page does not choose among them. What all sources share is the direction and the cause — the first direct exchange of fire since July 29, at the entrance to the Strait of Hormuz, through which roughly a fifth of the world's seaborne oil normally moves. The consequences were visible the same day: energy shares rose 0.9 percent while the S&P 500 fell 0.33 percent to 7,686.14, and September Fed rate-hike odds rose to about 62 percent
The three lines
- Direction — Brent back above $90, on the resumption of US-Iran fighting at the mouth of Hormuz
- Number — settlements were reported at 90.49, 90.69 and 91.09 dollars. This page does not pick one
- Spillover — energy shares +0.9 percent, September Fed hike odds about 62 percent
Key questions
- What was the oil price on August 31, 2026?
- **Brent was above 90 dollars a barrel and WTI was reported near 86.** The exact settlement could not be established here. Coverage of the same session gave Brent at **90.49 dollars (+2.71%)**, **90.69 dollars (+2.93%)** and **91.09 dollars (+3.4%)**. Three things typically produce this kind of spread. ① **Different contract months** — Brent for September and for November are different prices at the same instant. ② **Different times** — the official settlement and after-hours quotes get cited interchangeably. ③ **Different venues** — ICE futures and spot assessments are not the same number. Our standard is *only what is confirmed*, so this page records **the return above 90 dollars** as fact and leaves the rest as a range.
- Why did oil rise?
- **Because the United States and Iran resumed fighting at the entrance to the Strait of Hormuz.** US Central Command said American forces struck **two rocket launchers** on **Larak Island** because they were preparing to **disperse sea mines** into the waterway, and Iran's Islamic Revolutionary Guard Corps said it struck two US bases in Jordan in response. It was the **first direct exchange since July 29**. In normal conditions roughly a fifth of the world's seaborne oil moves through the 34-kilometre-wide strait. The important nuance: **supply was not actually cut on August 31.** Prices rose because the **probability** of a cut rose, and futures prices absorb changes in probability immediately.
- When does a higher oil price reach household spending?
- **Typically two to three weeks to reach the pump, and the pass-through is partial.** The chain has several stages: ① international crude moves, ② refiners buy and ship the crude, which takes time, ③ it is refined into gasoline and diesel, and ④ station prices change once existing inventory clears. Three additional points prevent misreadings. **Different benchmark** — Korea buys mostly Dubai crude, not the Brent or WTI quoted in the news ("The difference between Dubai, Brent and WTI"). **The exchange rate multiplies** — the won closed at 1,368.6 per dollar on August 31, so a flat dollar price can still mean a higher local one. **Tax is a large share** of a Korean pump price, so the percentage move in crude does not pass through one-for-one. And empirically, pump prices tend to **rise faster than they fall.**
On August 31 Brent crude moved back above 90 dollars a barrel. The cause was singular: the United States and Iran resumed fighting at the entrance to the Strait of Hormuz.
But this page cannot print the settlement. Here is why.
1. Why no single number
Coverage of the same trading session gave three different Brent settlements.
| Reported figure | Change |
|---|---|
| $90.49 | +2.71% |
| $90.69 | +2.93% |
| $91.09 | +3.4% |
The spread is 60 cents, or 0.7 percentage points of return. That looks small until you print one of them in a headline — at which point the other two readings make it wrong.
The usual causes:
| Cause | Detail |
|---|---|
| Contract month | Brent for September and for November are different prices at the same instant |
| Time of day | Official settlement and after-hours quotes get cited interchangeably |
| Venue and quote type | ICE futures and spot assessments are not the same number |
This page's standard is only what is confirmed. So: Brent returned above 90 dollars, up somewhere between 2.7 and 3.4 percent. WTI was reported near 86 dollars.
2. Why it rose
US Central Command said American forces struck two rocket launchers on Iran's Larak Island, on the grounds that they were preparing to disperse sea mines into the Strait of Hormuz. Iran's Islamic Revolutionary Guard Corps said it struck two US bases in Jordan.
It was the first direct exchange since July 29 ("US and Iran exchange fire on August 31, 2026").
The key nuance: no oil supply was actually cut on August 31. In normal conditions roughly a fifth of the world's seaborne oil passes through the 34-kilometre-wide strait. Prices rose because the probability of disruption rose, and futures prices price probability in real time.
3. One event, two directions
| Asset | August 31 |
|---|---|
| Brent crude | +2.7% to +3.4% |
| Energy sector equities | +0.9% |
| S&P 500 | −0.33% (7,686.14) |
| Dow | −374.09 pts (53,185.90) |
| September Fed hike odds | about 62% |
Higher oil is a cost for most companies and revenue for the ones that sell it. So the indexes fell and energy rose.
The last row matters most. Oil feeds directly into inflation readings, so a single Middle East session moves rate expectations. Odds of a 25 basis point September hike went from roughly 40 percent a week earlier to about 62 percent ("S&P 500 closes at 7,686.14 on August 31, 2026").
4. How this price reaches a household
| Stage | What happens | Lag |
|---|---|---|
| ① International crude | Brent, WTI, Dubai move | Immediate |
| ② Procurement | Refiners buy and ship crude | Weeks |
| ③ Refining | Gasoline and diesel produced | Days |
| ④ Retail | New price once inventory clears | 2–3 weeks total |
Three qualifiers keep this from being misread.
- The benchmark differs — Korea buys mostly Dubai crude, not the Brent or WTI in the headlines ("The difference between Dubai, Brent and WTI — the oil in the news is not the oil Korea buys").
- The exchange rate multiplies — the won closed at 1,368.6 per dollar on August 31. A flat dollar price can still mean a higher local one.
- Tax is a large share of a Korean pump price, so a percentage move in crude does not pass through one-for-one.
5. What is still unresolved
- The settlement — Which of 90.49, 90.69 and 91.09 is the settlement was not determined.
- The basis — Contract months and settlement times behind each figure were not identified.
- WTI — Near 86 dollars comes from reporting; the exact settlement was not verified.
- Transit — Changes in Hormuz traffic after this exchange have not been tallied.
- Pass-through — The two-to-three week lag is a historical norm, not a measurement of this particular move.
Sources
- Quartz — Brent crude oil tops $90 after U.S. strikes Iran
- The Hill — Oil prices surge after US attack on Iran's Larak Island
- The Motley Fool — Market Indexes Slip to Close Out a Winning, Turbulent August
- Trading Economics — Brent Crude Oil price and historical data
- Fortune — Current price of oil as of August 31, 2026