Forget the futures ticker for a second. Here is what the gallon costs.
As of September 10, 2026, AAA’s California diesel average is $7.91 per gallon — a new state high, about 20 cents above the $7.71 we logged on September 4. That is 70% more than January’s $4.66. National diesel is $5.98, also a new AAA record, and also 70% above January’s $3.52.
Regular unleaded moved too, just not as far: $4.28 nationally (+40% from January’s ~$3.06) and $5.90 in California (+27% from January’s $4.63).
That is the state average for diesel. Several California metros are already over $8. AAA’s San Rafael metro is $8.42. San Francisco is $8.29. San Luis Obispo is $8.29. Santa Rosa is $8.23. Oakland is $8.15. Full ranking: Diesel Prices by State Ranked. Map: Diesel Prices by State.
The $9.99 rumor vs. what AAA actually shows
AAA does not quote individual stations. It publishes daily averages. Nothing in today’s AAA California table is anywhere near $9.99. The highest metro diesel average AAA lists is San Rafael at $8.42.
Station-level reporting is higher than the state average, but still not $10. On September 4, CBS San Francisco found diesel at $8.39 at a Shell on Seventh and Market in San Francisco, and biodiesel at $8.29 at Oakland’s Golden Gate Petro. The $9.99 figure that keeps circulating is a different story: the Los Angeles Times reported in April that Gorda by the Sea in Big Sur posted $9.99 premium gasoline because the pump software cannot display $10. That was gasoline at a remote Highway 1 stop — not California diesel, and not an AAA quote.
At the pump since January — the percentages that hit your wallet
Oil futures are how traders talk. The percentage on the gallon is how households feel it. January → today:
| What you buy | January | Sept. 10 | Pump change |
|---|---|---|---|
| U.S. diesel | $3.52 | $5.98 | +70% |
| California diesel | $4.66 | $7.91 | +70% |
| U.S. regular gas | $3.06 | $4.28 | +40% |
| California regular gas | $4.63 | $5.90 | +27% |
In English: diesel at the pump is up about seven-tenths since the start of the year, in California and nationally. Regular gas is up about two-fifths nationally and a little more than a quarter in California — still a lot, and still not diesel’s year.
Same percentages on a fill-up:
- 20 gallons of diesel, U.S.: about $70 in January → about $120 today (+$50, +70%)
- 20 gallons of diesel, California: about $93 in January → about $158 today (+$65, +70%)
- San Rafael diesel (AAA metro $8.42): that same 20 gallons is about $168
- 15 gallons of regular, U.S.: about $46 in January → about $64 today (+$18, +40%)
- 15 gallons of regular, California: about $69 in January → about $88 today (+$19, +27%)
Versus a year ago, AAA’s California diesel average is still up about 53% ($5.16 → $7.91). National diesel is up about 61% versus last September ($3.71 → $5.98). Those are year-over-year pump moves, not futures.
What oil did — and why it is not the same as your gallon
On January 2, Reuters put the Brent settle at $60.75 a barrel and WTI at $57.32. This morning, Reuters had Brent around $105 (+73%) and WTI crossing $100 (+75%) after a fresh wave of tanker attacks in the Strait of Hormuz.
That is the barrel. You do not buy barrels. You buy gallons, with tax, refining, and California’s CARB diesel rules stacked on top. The useful comparison is that pump diesel (+70%) tracked crude’s year-to-date jump, while regular gas (+40% nationally, +27% in California) did not. Distillate inventories were already tight. Hormuz risk and damaged refining capacity hit diesel harder than unleaded — which is why the freight channel is the inflation story, not the oil-ticker screenshot.
Why California is the outlier
California already ran the most expensive diesel market in the country before this week. Taxes, CARB diesel specs, limited in-state refining, and West Coast logistics keep a floor under the price. The Iran war did not create that gap. It stretched it. On September 4, California was $7.71 against a $5.85 national record. Six days later the state is $7.91 against $5.98 nationally — still about $1.93, or 32%, above the U.S. average.
GasBuddy’s Labor Day recap had California diesel around $7.81 and the most expensive tenth of U.S. stations averaging only $6.47 nationally. California is not in the same distribution. It is the right tail.
The freight problem, not the tourist-pump problem
$8 diesel in San Rafael is not a Big Sur curiosity. Diesel moves groceries, packages, construction materials, and harvest equipment. When the state average is $7.91 and metros clear $8, fuel surcharges are already in the shipping bill. Households who never buy diesel still pay it later — on the shelf, not on the highway sign. That is the point of our Labor Day diesel record: regular gas is the visible sticker; diesel is how an oil shock leaks into CPI. WTI up 75% is the trader’s number. Diesel up 70% at the pump is the household number.
Sources: AAA Fuel Prices — California (diesel $7.9114, regular $5.8992 as of Sept. 10, 2026; San Rafael diesel $8.4226; San Francisco $8.2868; San Luis Obispo $8.2932); AAA national (diesel $5.9773, regular $4.2770); Reuters, Sept. 10, 2026 (Brent ~$105.26, WTI ~$100.04 as of 1215 GMT); Reuters/MarketScreener, Jan. 2, 2026 (Brent settle $60.75, WTI $57.32); EIA U.S. gasoline and diesel retail prices (January 2026 on-highway diesel $3.523); EIA California gasoline and diesel (January 2026 diesel $4.656); BTS Motor Fuel Prices, January 2026; CBS San Francisco, Sept. 4, 2026; GasBuddy, Sept. 8, 2026; Los Angeles Times, April 3, 2026 (Gorda $9.99 gasoline, not diesel). Related: Diesel’s Labor Day record, Labor Day gas above $4, Gas Prices Since Iran.