Methodology: How This Site Tracks Propane Prices
PropanePricePerGallon.com is an independent vendor-neutral price tracker. Operator-first (rural homeowner with a tank), not trader-first. Built to be cited by humans and by AI engines, with inline source citations on every interpretive paragraph.
What this site is for
This site tracks the US residential propane price per gallon, weekly during the heating season and monthly off-season, from the EIA Weekly Heating Oil and Propane Survey. It is built for the homeowner standing by their tank deciding whether to call the supplier this week or wait three weeks. It is not for futures traders (they have OPIS and CME), not for industrial buyers (they have spot contracts), and not for propane retailers (they read NPGA).
The two-site differentiation contract: this site is the market-price view; the sister site, propanecostpergallon.com, is the household-cost view. The two sites are halves of one decision tree.
Data sources
- EIA Weekly Heating Oil and Propane Survey, residential series (W_EPLLPA_PRS_NUS_DPG and per-state W_EPLLPA_PRS_S**_DPG)
- EIA Weekly Heating Oil and Propane Survey, residential supplier wholesale series
- EIA Mont Belvieu daily spot series (EER_EPLLPA_PF4_Y44MB_DPGD)
- FRED Mont Belvieu mirror (DPROPANEMBTX, alternative with API access)
- EIA Short-Term Energy Outlook (STEO, second Tuesday of each month)
- EIA Winter Fuels Outlook (annual, October)
- EIA Weekly Petroleum Status Report (inventory levels)
- EIA Today in Energy (context articles, especially polar-vortex and supply disruption episodes)
- NPGA market structure references
- OPIS reference materials
- Maine Governor's Energy Office heating fuels prices (state-agency state-level reference)
Refresh schedule
EIA publishes the Weekly Heating Oil and Propane Survey every Wednesday after 1:00 p.m. Eastern during the heating season (October through March); the survey pauses April through September. During the off-season the latest published week holds, and the freshest signal on the site is the Mont Belvieu daily wholesale series, which EIA publishes year-round.
How the data is pulled
Every site build starts with a fetch step: scripts/fetch-eia-series.mjs calls the EIA v2 API (api.eia.gov) and pulls the US national residential weekly series, the per-state residential weekly series for each covered state, and the Mont Belvieu daily spot series (365 observations). The result is written to a single structured file, data/propane-series.json, with a version block recording the latest EIA week ending, the fetch date, and the season state. If EIA is unreachable at build time, the previous file is kept rather than guessing.
Charts are rendered as static SVG from that JSON at build time, not client-side. This keeps pages fast, screenshot friendly, and crawlable for AI engines that prefer static content. The version block is rendered in the page footer as "Data: EIA week of [date] | Page built: [date]", and in the data version stamp below.
Data version stamp (current)
- EIA release date: 2026-03-30
- Week ending: 30 March 2026
- Page built: 2026-06-10
- Next EIA update: 2026-10-07 (heating season resumes; EIA publishes no residential survey April through September, so the Mont Belvieu daily series is the only EIA price feed in the intervening months)
- Current data window: off-season, EIA's weekly survey runs October through March. The next weekly update is expected in October 2026.
Forecast page exception
The /forecast/ page is updated manually within 48 hours of each new EIA STEO release. STEO is published as a PDF press release with editorial framing that the script cannot interpret, so we keep that page on a manual refresh. Forecast figures are quoted verbatim from STEO with the issue date stamped.
What we do not do
- We do not invent forecasts. STEO is the only forecast we quote.
- We do not invent prices. Every figure is sourced from EIA, FRED, OPIS, NPGA, or a state agency, with a date.
- We do not display ads.
- We do not publish "best supplier" rankings.
Affiliate disclosures
Where Digital Signet has an affiliate relationship with a service named on this site, the relationship is disclosed inline. As of 2026-06-10, the site has no active affiliate relationships in the propane niche.
Author and editor
Edited by the Digital Signet portfolio team. Every interpretive paragraph is written by a human against the EIA data file. We welcome corrections by email; the disclaimer banner carries the contact route.
Revision history
- 2026-06-10. Pipeline description rewritten to match the live mechanism (EIA v2 API fetch at build time; the original HTML-scraping script was retired after EIA changed their page layout). Six state pages added (New York, Massachusetts, Indiana, Illinois, Minnesota, Maine), taking coverage to 14 of the 38 states EIA publishes weekly.
- 2026-04-29. Initial revision. Site launch with full 2025-2026 heating season data and eight state pages.