Muntin Open Data → Seasonality
What actually moves produce prices?
Seasonality is the yearly rhythm in what an ingredient costs — set by harvest, storage, imports and weather. The honest headline: a handful of fresh field crops reward timing, and most storage crops, year-round imports, and proteins do not.
What is at its seasonal low
Pick a month on the clock — or let it open on the current month. These ingredients are usually at their cheapest point of the year then. The “% cheaper” is how much less they cost now than in their most expensive month — like a discount. Higher means a better time to buy.
What seasonality is
Seasonality exists because fresh food is grown, not manufactured. Supply arrives on nature’s schedule while a kitchen’s demand stays roughly steady, so price moves to close the gap. Four mechanisms do most of the work.
Harvest window
When a crop's main growing region is cutting at full volume, supply floods the market and price bottoms.
Storage
Cold- or controlled-atmosphere crops are harvested in a tight window and metered out all year, which flattens the curve.
Imports
Year-round supply from Mexico, Chile and Peru fills the off-season — or imposes its own foreign harvest cycle.
Weather
A frost, a heat spell, or heavy rain in a growing district passes straight to price for perishables with no storage buffer.
Which mechanism dominates is the whole story for an operator. A crop with a defined domestic harvest and no place to hold it swings hard; one that stores well or ships from imports every month prices close to flat. Often several forces stack — a domestic harvest low, an import shoulder, and a holiday demand spike layered on top.
Where timing actually pays
The ingredients that most reward good timing — "% cheaper" is how much less each costs in its cheapest month than in its priciest, from the multi-year history. Tap any for its full curve.
Deliberately excluded: Green onion, Lime show even larger raw swings that are almost certainly a pack or unit change between summer and winter fruit, not a real price move. The direction is reliable; the exact multiple is not.
How to read the 12-month curve
Every ingredient page carries a 12-month curve built from multi-year medians. The line is each month’s median (typical) price — the middle of the historical range, so one freak year doesn’t distort the shape. The shaded band is the spread: how much that month has varied year to year. A tight band means dependable; a wide band means volatile.
We flag the cheapest month, the priciest, and the amplitude — the percent gap between them — which is the single best gauge of whether an item is worth timing at all. Two cautions: check the band before you commit spec, and remember the line is a median, not a forecast.
The operator’s playbook
- Read the cheapest month as your feature-and-buy window and the priciest month as your trim-or-substitute window.
- When the amplitude is large, the calendar is worth building the menu around: feature the item at its low, substitute or pre-buy ahead of its high.
- When the amplitude is small — under about 15-20% — the curve is mostly noise: buy to need and shop the current spot deal instead.
- Check the spread band before you commit spec: a cheap month with a wide band can still spike.
- Remember the line is a median, not a forecast. It tells you the usual rhythm, not what next week’s truck will cost.
Where the calendar barely matters
Most of the index is closer to flat than seasonal, and pretending otherwise would waste an operator’s time. Of 74 classified ingredients, only 57 carry a clear seasonal window; 14 are moderate and 3 are effectively flat.
Storage bulbs (onion, garlic), roots (potato, carrot, beet), pome fruit (apple, pear), year-round imports (banana, pepper) and hard herbs move in single-digit to ~20% bands — that’s normal noise, not a signal. Proteins are commodity markets on feed and fuel cycles, not a harvest calendar.
Storage is the great flattener: a crop can be intensely seasonal in the field and still price flat because controlled-atmosphere storage meters it out all year. And these curves are multi-year medians — a single-year frost, disease event, or freight shock can override the calendar in any given month.
Derived from the deep public history (USDA, BLS, FRED). The numbers are public domain (CC0). Back to Open data