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The 2012 US drought: corn futures across two harvests

Jun – Sep 2012

The lesson: CBOT corn (ZC=F) rose 22.3% from Feb to Aug 2012 month-end, then fell 38.3% by Aug 2013. Those comparisons span different harvests and contracts; they do not isolate drought damage or establish that the next harvest will reverse a weather shock.

What happened

The fastest-planted corn crop on record met a brutal summer. On 11 Jul 2012 USDA's World Agricultural Outlook Board cut the US corn crop estimate by 1.82 billion bushels — about an eighth — in a single month, citing 'persistent and extreme June and early-July dryness and heat'; nearly four-fifths of US corn acreage sat inside drought areas (USDA, 12 Jul 2012). The 10 Aug Crop Production report put yield at 123.4 bushels per acre, down almost 24 from 2011 and the lowest since 1995/96, with production of 10.8 billion bushels, down about an eighth from 2011 — despite the most corn acres planted in 75 years. The final tally was 10.78 billion bushels, less than three-fourths of the spring forecast (AP, Jan 2013). No US export restrictions were imposed; the extent of demand adjustment is not estimated here.

Weather context
  • United States (Iowa corn belt centroid) (May-Oct 2012): +1.38°C vs the 1991–2020 baseline; rainfall -34.7% vs baseline (140 days with <1mm rain). The 2012 growing season ran hot and dry at this Iowa centroid: +1.4 C vs baseline, rainfall about a third below normal, with 140 of 184 days recording under 1mm of rain.

One region centroid is illustrative, not field-level truth; baseline is the 1991–2020 day-of-year mean. Weather data provided by Open-Meteo.com.

What everyone expected

CBOT corn was 'soaring to over $8 a bushel on July 23 (from $6 at the end of June) with projections from Goldman Sachs that it could reach $9 per bushel in three months' (Union of Concerned Scientists, Jul 2012). The Kansas City Fed warned the drought could add about four percent to annual food prices over the next year.

As reported at the time: Union of Concerned Scientists, Jul 2012 · Kansas City Fed via Weather Channel, Aug 2012

Observed prices and measurement limits

These are changes in the named benchmarks over the stated windows, not estimates of the event’s effect. Endpoints omit interim moves. A supply shock may have kept prices above where they would otherwise have been, even if the measured change is negative.

  • Corn
    2012-02 → 2012-08 · ZC=F month-end closes
    +22.3%

    The run-up into the August peak.

  • Corn
    2012-06 → 2012-08 · ZC=F month-end closes
    +19.4%

    Two months, a fifth higher.

  • Corn
    2012-08 → 2013-08 · ZC=F month-end closes
    -38.3%

    CBOT corn fell from August 2012 to August 2013 month-end. The window spans another harvest and does not isolate weather recovery.

Month-end closes smooth the intraday peak — $8.49 per bushel on 10 Aug (Fast Company) — so the monthly series understates the panic high. The year-later decline mixes drought recovery with a large 2013 planted area.

Evidence and interpretation

USDA documented a lower crop outlook during the drought, and EIA reported pressure on ethanol margins. Less expected supply could support corn prices; weaker processing demand could ease that pressure. The year-later comparison also spans another crop. This record does not estimate the separate contributions of supply, demand, planted area, or futures rolls to the price path.

How this record has changed

Living document — every material change is logged here, newest first.

  1. Correction2026-09-25

    Revised the lesson and interpretation after commodity-trader feedback: price-window comparisons do not identify causal effects, and a declining price does not establish that a supply shock had no supportive effect. Removed unsupported claims about offsetting drivers and clarified benchmark and window limits.

    Commodity-trader feedback supplied by the user; editorial review of bundled event observations (25 Sep 2026)

  2. New evidence2026-09-17

    Added ERA5 weather reanalysis context for May-Oct 2012 at the Iowa corn belt centroid: +1.38 C mean temperature anomaly vs the 1991-2020 baseline, rainfall 34.7% below normal, 140 of 184 days under 1mm. Derived from Morrowfly's research vintage v1_2026-09-15 (raw daily series stay in research; only derived anomalies shown). Attribution: weather data provided by Open-Meteo.com.

    Morrowfly research vintage v1_2026-09-15 + 2026-09-17 window addendum (ERA5 reanalysis via Open-Meteo)

  3. Correction2026-09-15

    Seed revision marking this record as published under the adversarial-review standard established 2026-09-15: outcome figures recomputed from Morrowfly's own month-end price history, intraday peaks confined to mechanism prose, and no bare '%' figures in narratives. Applied at creation, before any public revision.

    Morrowfly internal adversarial review standard (15 Sep 2026)

Transmission

  • Corn
    production loss

    The US is the top corn exporter; the drought cut the US crop by about a quarter from spring expectations (USDA NASS, Aug 2012; AP final report, Jan 2013).

Sources

Notes

  • Prices are monthly averages from our series (World Bank Pink Sheet; crude: EIA) unless noted; windows are labeled beside each number.
  • Generic futures series do not identify the delivery month at each observation or document the provider’s roll schedule and adjustment method. These price comparisons are not returns from holding one contract or following a specified roll strategy. Wheat comparisons also depend on protein, end use, and crop calendar.
  • Secondary press quotes are reported as published and were not individually audited against primary sources.
  • Illustrative scenario record. Not a prediction. Not financial advice.