The data behind the site
Understanding EIA propane data (what this site is built on)
This site runs on two EIA data streams: a weekly survey of residential and wholesale propane prices that runs only during the October-through-March heating season, and weekly propane inventories that run all year. Knowing which stream a number comes from, and when it updates, is the whole trick to reading the site.
Updated Jul 9, 2026
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Nearly every number on The Fill Line comes from the US Energy Information Administration, and it arrives in two separate streams. One is a weekly survey of residential and wholesale propane prices that runs only during the October-through-March heating season. The other is weekly propane inventories, plus the supply balance behind them, that run all year. Tell those two apart and you can read any page here, including why the price pages go quiet every summer while the inventory pages never do.
The price stream: a heating-season survey
Retail and wholesale propane prices come from EIA's State Heating Oil and Propane Program, collected through a survey EIA labels the EIA-877 Winter Heating Fuels Telephone Survey. Every Monday from the first Monday in October through March, EIA and cooperating states phone a statistical sample of propane dealers, around 645 of them, and record the residential price customers paid that Monday, taxes excluded. Wholesale prices are collected the same way. The results publish weekly, updated each Wednesday after 1:00 p.m. Eastern.
The survey is heating-season only by design. From April through September no residential price is collected, so those pages freeze at the last winter reading and say so. The pause is the survey's structure, not a gap on this site's end.
The US price table above shows the effect: the latest reading is dated to the end of March, the last week the survey ran, with the off-season note attached. It resumes in October.
The inventory stream: year-round and weekly
Propane stocks come from EIA's Weekly Petroleum Status Report, out every Wednesday and covering the prior week, year-round. The same report carries the weekly supply balance: production, imports, exports and product supplied. Product supplied is EIA's proxy for demand. It measures the volume that left the primary supply chain, refineries, gas plants, pipelines and bulk terminals, on its way to the market, which EIA calls implied demand because it is measured upstream of the actual sale.
The stocks table above keeps updating every week of the year, summer included. When the price pages are frozen for the season, this is the stream carrying the story.
The third stream: the daily hub price
One more EIA series rounds out the site: the Mont Belvieu propane spot price, published daily for business days, year-round. Mont Belvieu is the Gulf Coast hub where US propane is priced, and the daily spot is the fastest-moving public number in the market. It is the base the wholesale and retail prices build on, so in the summer, with the retail survey paused, the spot page is where price news happens first. How the hub price becomes a delivered price is its own guide.
What is surveyed, and what is not
Two limits are worth stating plainly. First, the weekly stocks number counts propane and propylene together, because the two share storage and pipeline infrastructure. Propylene is mostly petrochemical feedstock, not heating fuel, so this site says propane and propylene where it matters and never builds an argument on the split. Second, the stocks number covers primary storage only. The propane in dealer plants and in the tank behind the house is not in it, which is why the retail market can feel tighter than the national inventory looks during a cold snap.
Normal means the five-year median here
When a page says stocks are a certain percent above or below normal, normal is the median value for that same calendar week across the prior five years. EIA's own reports use the five-year average. This site uses the median, which one freak year cannot drag as far, and labels it as vs 5-yr median everywhere so the two are never confused. The math behind every comparison is spelled out on the methodology page.
Being open about the data source is the point of this guide. The Fill Line reports EIA's published figures and attributes them to the dataset they came from. It does not forecast, and where it ever cites EIA's own outlook it labels that as EIA's forecast, not this site's.
The Fill Line is a free weekly read of the public propane numbers. Stocks, the Mont Belvieu spot and the weekly supply balance update year round; the state price survey resumes in October. One email a week on what moved.
Now look at the live data
Common questions
Why do the propane price pages stop updating in March?
Because EIA's residential and wholesale price survey runs only during heating season, October through March. From April through September the survey collects no prices, so those pages show the last winter reading and a note that the survey resumes in October. The stocks, spot and supply pages update all year.
What is product supplied?
It is EIA's proxy for propane demand. Product supplied measures the volume that left the primary supply chain of refineries, gas plants, pipelines and bulk terminals for the market. EIA calls it implied demand because it is measured upstream of the final sale, so it is the closest weekly read on consumption the public data offers.
Why do the stocks numbers say propane and propylene?
EIA's weekly inventory series counts the two together because they share storage and pipelines. Propylene is mostly a petrochemical feedstock rather than a heating fuel. This site follows EIA's series and says propane and propylene where it matters, rather than pretending to a split the data does not provide.
How often does the data update?
The weekly EIA data lands on Wednesdays, covering the prior week. In heating season the price survey publishes Wednesday afternoon; the Weekly Petroleum Status Report carries stocks and supply year-round. The Mont Belvieu spot updates daily. Every page shows a last-updated date pulled from the data itself.