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 price pattern that typically peaks in late January or February and troughs in August or September. The chart shows the last five calendar years overlaid on a single 12-month axis.
The 5-year overlay chart
When is the cheapest month, on average?
Based on the 10-year EIA monthly archive (calendar years 2016 through 2025, averaged across each month), the cheapest months are August and September; the most expensive are January and February. The difference between the average summer trough and the average winter peak is roughly 20 to 25 cents per gallon in a normal year. In an abnormal year (2014, 2022) the gap can exceed 80 cents.
| Month | 10-year average ($/gal) | Note |
|---|---|---|
| Jan | $2.488 | Heating-season peak |
| Feb | $2.531 | Heating-season peak |
| Mar | $2.504 | |
| Apr | $2.443 | |
| May | $2.378 | |
| Jun | $2.331 | |
| Jul | $2.302 | |
| Aug | $2.286 | Summer trough (best fill window) |
| Sep | $2.293 | Summer trough (best fill window) |
| Oct | $2.339 | |
| Nov | $2.398 | |
| Dec | $2.451 |
Source: EIA M_EPLLPA_PRS_NUS_DPG, calendar years 2016 through 2025 averaged. Months with the same name across years are arithmetic mean. 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 $4.011, low $2.382, average $2.808.
- 2020. Pandemic demand drop kept prices flat through summer. Annual high $2.158, low $1.957, average $2.078.
- 2022. Russia-Ukraine supply disruption raised the global NGL floor. Annual high $3.019, low $2.661, average $2.853.
The implication: a buyer who fills only in August 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 historical August trough sits closer to $2.30 in a normal year. A homeowner who tops up in late August or early September would, on a 10-year average, pay 30 to 40 cents per gallon less than in late March; on a 400-gallon fill, that is $120 to $160. 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.