The Best Time to Buy a Used Car, According to 14 Months of Price Data

Everyone has a theory about the best month to buy a car. We have fourteen months of asking-price data. Tracking a fixed basket of vehicles from June 2025 through August 2026 shows that used prices do not fall evenly — they slide in steps, pause completely in early spring, and take their biggest single drop in May.

When prices actually move

Three phases stand out:

• Fall and early winter (September–January): the steady slide. Prices step down 1–1.6% almost every month as dealers clear aging stock and the next model year arrives.
• February–April: the spring plateau. For three straight months the index barely moves. Tax-refund season pours buyers onto lots, and sellers simply stop cutting.
• May: the reset. When the spring wave passes, prices take their single largest step down — −2.7% in one month.

So when should you buy?

• Best window: late December – January. You catch the full fall slide before the spring plateau freezes prices. Waiting from January to April saved essentially nothing in 2026.
• Second-best: May–June. If you missed winter, the post-plateau reset is real — May 2026 alone gave back more than the whole February–April stretch.
• Worst window: February–April. You pay winter’s price while competing with tax-refund demand.
• The caveat that beats every calendar: the seasonal swings total about 3 points, while model choice swings ten times that — see our depreciation study and price trends report.

Methodology notes

Same fixed basket as our price-trends index: 31 (make, model, model-year) series with at least 50 tracked VINs in each of the 15 months from June 2025 to August 2026; monthly change is the step in the basket’s median relative index. This covers one seasonal cycle — we will re-run the study as the archive grows, and treat single-cycle seasonal claims with appropriate caution. August 2026 is a partial month (snapshot August 4). See how we build these studies.