Diesel stopped being background noise for ingredient buyers this year. It became a line item volatile enough to rewrite freight contracts and shelf prices inside a single quarter. The numbers from the past five months show why.
The trigger was geopolitical, not agricultural. The U.S.-Israel war with Iran began in late February 2026 and escalated into Iranian control over shipping through the Strait of Hormuz, the waterway that normally carries roughly 20% of the world’s oil supply. Average daily vessel transits fell 95% at the height of the blockade, according to UN Conference on Trade and Development data cited by the Chicago Sun-Times. Nothing has moved U.S. diesel prices that fast since Russia’s invasion of Ukraine in 2022.
The five-month timeline
National average diesel was still under $4 a gallon in early 2026. Then, per FreightWaves, prices jumped nearly $1 a gallon in a single week in March, the largest weekly increase the U.S. Bank Freight Payment Index report had on record. By early May, FreightWaves’ SONAR retail diesel index had climbed above $5 a gallon, reaching $5.68.
The climb continued into mid-May. The national average hit $5.64 a gallon on May 21, just 19 cents shy of the June 2022 record of $5.83. Chicago set an outright metro record of $6.30 on May 15, and Illinois hit $6.14, a 71% year-over-year jump from $3.63 the previous May, according to GasBuddy data reported by the Sun-Times.
By EIA’s most recent release, dated July 14, 2026, national on-highway diesel had eased to $4.796 a gallon for the week ending July 13, up 21.8 cents from the week before. It remained $1.038 higher than the same week a year earlier and 97 cents above two years earlier, per the EIA Gasoline and Diesel Fuel Update. The acute shock has cooled. The baseline has not come back.
Where the cost actually comes from
EIA’s March 2026 cost breakdown for a $4.92 gallon of diesel attributed 42% to crude oil, 34% to refining, 12% to distribution and marketing, and 12% to taxes. That split matters because crude and refining together account for more than three-quarters of the pump price, precisely the portion most exposed to another Hormuz-style disruption.
Freight math moves on a lag
Pump prices and freight costs are not the same number. Most carriers and parcel networks reset fuel surcharges weekly against the national average diesel figure, then compound that with capacity conditions. The U.S. Bank Freight Payment Index showed shipper spending up 21.8% year-over-year and 12.9% quarter-over-quarter in Q1 2026, even as shipment volumes stayed essentially flat, down 0.3% quarter-over-quarter, according to FreightWaves.
That gap between flat demand and surging cost is the real signal. Carriers used tightening capacity, exiting owner-operators, and rising fuel costs to push pricing power back in their favor. DAT-reported spot truckload rates rose nearly 12% quarter-over-quarter as a result.
Parcel and less-than-truckload networks moved just as fast. FedEx’s ground, home delivery, international ground and pickup surcharge rose to 27.25%, itself 25.2% higher than pre-war levels. UPS added a 27.75% fee on domestic ground packages starting May 18. USPS took the more conservative route with a flat 8% rate increase effective April 26, running through January 27, 2027, citing rising transportation costs and competitor surcharges it said it had “steadfastly avoided” until then, per the Sun-Times.
Why perishable ingredient chains feel it first
For ingredient buyers specifically, the transmission runs through perishability and distance. Fresh and specialty supply chains that depend on multiple short-haul legs, seafood flown and trucked from South America, for example, absorb a fuel surcharge at each point along the route, according to a seafood market analyst cited in a New York Times report picked up by PYMNTS. That reporting, published March 31, 2026, put the average diesel price increase since the war began at 44% at that point, a snapshot from roughly five weeks into the conflict and well before diesel’s mid-May peak.
The mechanism matters directly for this publication’s beat. Botanical raw materials that move through multiple freight legs before reaching a U.S. formulator, dried root powders like ashwagandha and turmeric out of India, maca out of Peru, matcha out of Japan, absorb the same stacked surcharges described above. None of those categories are perishable the way fresh seafood is, but none are exempt from a fuel surcharge charged at every leg of a multi-country supply chain either.
Farm-level diesel, a major spring planting input, rose 46% since the end of February, according to an American Farm Bureau Federation survey of 5,700 farmers cited by the Sun-Times. The Green Markets Weekly Fertilizer Price Index, which tracks a crude-oil-linked input, was up 30% year-over-year. Both flow into the landed cost of any agricultural raw material months before it ever reaches a truck. That is exactly why botanical and organic ingredient buyers should be watching farm-input inflation now rather than waiting for a freight invoice to confirm it.
The hedging response is the practical half of the story
Attara, a commodity risk advisory that works with dairy processors, reported a 300% increase in hedging activity in the weeks after the Hormuz disruption began, according to FoodNavigator-USA. The surge was driven largely by small and mid-sized agricultural businesses that had never used corporate-style hedging tools before.
In the weeks after the disruption began, the firm’s specialists were steering clients toward monthly fuel swaps, agreements that convert an unpredictable input cost into a fixed one by exchanging only the difference between contract and market price. The incentive to move early was measurable, not theoretical.
Businesses which delayed hedging during this spring’s fuel volatility faced 26% higher costs on average than those that hedged proactively, according to Attara’s internal data.
What buyers should do with this
Diesel has retreated from its war-driven peak but remains up more than a dollar a gallon year-over-year, with no clean signal of returning to 2024-2025 norms. Freight and parcel surcharges reset on a lag against the national average, so cost relief will arrive slower than cost increases did.
The small and mid-sized buyers who avoided hedging through the spring spike are the ones now paying the widest margin penalty. Locking in multi-month fuel or freight-rate commitments, even short ones, has moved from a nice-to-have to a demonstrated cost saver for smaller operators who previously left that tool to the majors.
For ingredient buyers running multi-leg, perishable, or farm-linked supply chains, that shift in behavior is no longer optional homework. The 26% gap FoodNavigator-USA’s source data showed between the prepared and the exposed remains the clearest number in this whole story. Proactive hedging beat reactive hedging by a wide margin during the spring shock, and that same logic still applies to any input cost buyers expect to stay volatile.