The Weekly Fill-Up | August 31 - September 4

August 31, 2026

September is here, and the energy markets are entering an important transition.

Across eastern South Dakota, attention is beginning to move toward harvest, grain drying, fall fieldwork, and eventually winter heating. For Sioux Valley Coop members, that means the next several weeks could bring noticeable changes in demand for diesel, propane, and lubricants.

The latest market data gives us a mixed picture. Propane continues to enter fall with a strong supply position. Diesel inventories, on the other hand, have taken another step lower. Meanwhile, developments overseas are keeping pressure on the global diesel market at a time when agricultural demand here at home is preparing to increase.

Diesel Inventories Take Another Step Down

Diesel remains the market that deserves the closest attention heading into September.

The latest U.S. Energy Information Administration data showed national distillate inventories falling from approximately 105.6 million barrels on August 14 to 103.4 million barrels on August 21. That’s a decline of more than 2.2 million barrels in just one week.

The Midwest was more stable. Regional distillate inventories increased slightly from approximately 28.4 million barrels to 28.6 million barrels.

That distinction is important for Sioux Valley Coop members. The immediate Midwest supply picture has held relatively steady, but the national market continues operating with a limited inventory cushion.

There is also new pressure coming from overseas.

Russia officially extended its diesel export ban through September 30 as the country continues dealing with domestic fuel shortages and refinery disruptions. Russia is normally one of the world’s largest diesel exporters, so removing those gallons from the international market forces buyers to look elsewhere.

We are already seeing that happen. Turkey, which historically relied heavily on Russian diesel, dramatically increased purchases from the United States and India during August. Increased international demand for U.S. diesel can create additional competition for the same refined-fuel supply serving the domestic market.

None of this means eastern South Dakota is facing a diesel shortage. It does mean we’re heading toward harvest in a market where supply deserves attention.

For producers, having bulk tanks ready and communicating anticipated harvest needs early can help Sioux Valley Coop plan deliveries efficiently as agricultural demand increases.

Propane Keeps Building Before Fall Demand

Propane continues to tell a very different story.

U.S. propane and propylene inventories climbed from approximately 107 million barrels on August 14 to roughly 109.5 million barrels on August 21.

Midwest propane inventories also continued moving higher.

That means the industry is entering September with a significant amount of propane already positioned ahead of grain drying and winter heating demand.

This is encouraging, but there is an important distinction between having propane in storage nationally and having gallons positioned where and when customers need them.

Once grain drying begins across the Midwest, demand can become concentrated very quickly. A wet corn crop can create significant regional propane consumption within a relatively short period. Transportation capacity, terminals, pipelines, storage, and delivery scheduling all become part of the supply equation.

That’s why strong summer inventories are valuable. They provide a larger cushion before seasonal demand begins drawing those stocks back down.

Propane Contracting Is Still Worth a Conversation

The current supply picture also creates an important opportunity for propane customers who have not yet considered contracting.

A propane contract isn’t a prediction that today’s price will be the lowest price available all year. It’s a way to establish greater certainty around an expense you already know is coming.

For a homeowner, that may mean budgeting for winter heating. For an agricultural operation, it may mean preparing for grain drying. For a business, it can make seasonal energy expenses easier to forecast.

Sioux Valley Coop offers several contracting options, including 100% prepay, no-money-down contracting, and consumption billing.

Customers who haven’t discussed their expected propane needs yet still have time to talk with the SVC team about which option makes the most sense for their situation.

Bulk Oil: September Brings a Different Kind of Demand

The conversation around bulk oil also changes as we enter September.

At this point, the question isn’t simply whether equipment has received its preseason oil change. Producers need to think about what happens after equipment starts accumulating long harvest hours.

Engines, hydraulic systems, transmissions, final drives, gearboxes, and bearings will soon be operating under some of their heaviest workloads of the year. Service intervals that seemed far away during preseason maintenance can arrive surprisingly quickly once machines begin running day after day.

This is a good time to compare lubricant inventory against expected harvest usage.

Consider not only engine oil, but also hydraulic fluid, gear oil, transmission fluids, grease, antifreeze, and other products your equipment routinely requires. For operations that consume larger quantities, having bulk oil on hand can reduce the need to track down product in the middle of harvest.

The goal isn’t to stock products unnecessarily. It’s to make sure the products you know you’ll use are available before you need them.

The Crop Is Becoming Part of the Energy Market

One of the biggest changes between August and September is that crop development begins turning into actual energy demand.

South Dakota is expecting approximately 5.79 million acres of corn harvested for grain this year, according to USDA’s latest 2026 state estimates. That represents a significant amount of crop that must be harvested, transported, handled, and potentially dried.

Every step carries an energy requirement.

Combines and tractors consume diesel. Grain trucks add transportation demand. Grain dryers can create significant propane consumption. Equipment operating for extended hours increases lubricant usage.

That’s why agricultural energy markets can change quickly once harvest gets underway.

The biggest variable for propane will be moisture. The amount of corn harvested matters, but the moisture level of that corn may matter even more when estimating grain-drying demand. Over the coming weeks, crop maturity, temperature, precipitation, and harvest conditions will give us a much clearer picture of how significant that demand could become.

Heading Into September

The energy markets aren’t sending one single message as August comes to an end.

Diesel inventories have moved lower nationally, and international supply disruptions are creating additional competition for refined fuel. Propane inventories continue building and enter September from a much stronger supply position. Bulk oil availability gives producers an opportunity to position maintenance supplies before equipment begins accumulating harvest hours.

For Sioux Valley Coop members, the next step isn’t trying to predict exactly where every market will move.

It’s knowing what your operation will need.

Review bulk fuel storage and expected harvest consumption. Consider whether a propane contract could make budgeting easier. Check lubricant inventory against anticipated service intervals. And as harvest approaches, communicate expected needs with the Sioux Valley Coop team.

Markets can change quickly once fall demand begins. The more that can be planned before that happens, the easier it is to keep farms, homes, and businesses moving when the season gets busy.

Sources

U.S. Energy Information Administration (EIA) – Weekly Petroleum Status Report, August 26, 2026
U.S. Energy Information Administration (EIA) – U.S. and Midwest Distillate Fuel Oil Stocks, week ending August 21, 2026
U.S. Energy Information Administration (EIA) – U.S. and Midwest Propane/Propylene Stocks, week ending August 21, 2026
USDA National Agricultural Statistics Service (NASS) – 2026 South Dakota Agriculture Overview, updated August 30, 2026
USDA National Agricultural Statistics Service (NASS) – Crop Progress Report, August 24, 2026
Reuters – Russia Extends Diesel Export Ban Through September, August 29, 2026
Reuters – Turkey Increases U.S. and Indian Diesel Imports Following Russian Supply Restrictions, August 27, 2026