Propane Price Seasonal Patterns: When Prices Rise and Fall (2026)
Propane production is roughly constant year-round; demand is highly seasonal. The result is a residential price that opens each survey season at its published low in October and typically peaks in February. The EIA residential survey runs October through March only, so the published data covers the heating season; dealer summer-fill quotes in the April-September gap are not surveyed. The chart shows the last five heating seasons overlaid.
The 5-season overlay chart
When is the cheapest month, on average?
Within the published EIA archive (2016 through the 2025-26 season, averaged across each month), October is the cheapest published month at $2.294 per gallon and February the most expensive at $2.484, a 19-cent average gap. In an abnormal season the gap is far larger: the 2021-22 season ran from $2.663 in October to $2.993 in March, and the 2024-25 season from $2.420 to $2.746. EIA does not survey April through September; dealer summer-fill programs in that window typically quote below the October open, and the year-round Mont Belvieu wholesale series bottomed in the August-November window in the most recent cycle.
| Month | Archive average ($/gal) | Note |
|---|---|---|
| Oct | $2.294 | Season open; cheapest published month on average |
| Nov | $2.343 | |
| Dec | $2.390 | |
| Jan | $2.424 | |
| Feb | $2.484 | Heating-season peak on average |
| Mar | $2.480 | Survey closes end of March |
Source: EIA M_EPLLPA_PRS_NUS_DPG, published readings 2016 through the 2025-26 season close, arithmetic mean per month. The survey publishes October through March only. The pattern holds across all years; the level shifts.
When the pattern breaks
The seasonal shape is a tendency, not a rule. Three years in the recent archive show meaningfully different shapes:
- 2014. Polar vortex spike, winter heating premiums never seen since. Annual high $4.010, low $2.368, average $2.856.
- 2020. Pandemic demand shock; the cheapest year in the series. Annual high $2.010, low $1.772, average $1.909.
- 2022. Russia-Ukraine supply disruption raised the global NGL floor. Annual high $3.019, low $2.660, average $2.759.
The implication: a buyer who fills in the summer or early-autumn window every year wins on average over a long horizon, but does not always win in any single year. A buyer who tries to time individual cold snaps will beat the average sometimes and miss it sometimes. The decision is probabilistic, not certain.
What the data implies for 30 March 2026-onwards
The 2025-2026 heating season ended at $2.674 per gallon. The published archive puts the average October open 19 cents below the average February peak, and dealer summer-fill quotes (unsurveyed by EIA) typically sit below the October open. On a 400-gallon fill, a 19 to 30 cent per gallon saving is $76 to $120. This is the underlying basis for the "summer fill" advice published by every state cooperative extension. The size of the saving in any particular year depends on the autumn inventory build and on crude movement.