· Analytic
LH THI Iowa Minnesota Severe-30d
Heat stress accumulation in the US hog belt, read as a daily signal for how much US pork production the next 60 days will deliver versus trend.
At a glance
Current reading
-0.425
moderate-negative band, cool fall conditions
Signal state
Moderate NEG
phase -1, 20 trading days in state
36-year sample
8,986 observable fwd60d days
1990-11-29 to Oct 30, 2026
Historical IC
+0.0223
Spearman vs LH fwd60d, p = 0.035 (AS_IS direction)
Baseline LH fwd60d
+0.26%
Unconditional mean
Extreme-pos fwd60d
+1.64%
+1.38 pp above baseline, strongest state
As of Oct 30, 2026. Updated nightly.
OBJECTIVE
Hogs have no functional sweat glands. When daytime temperatures and humidity push past the 84 THI severe threshold for sustained stretches, finishing animals eat less, gain weight slower, and the breeding herd conceives at lower rates. Iowa and Minnesota together carry roughly 40 percent of the US hog inventory, so when the hog belt bakes the whole production pipeline tightens six to eight weeks forward. This signal counts severe-and-moderate stress days on a rolling 30-day window across the Iowa-Minnesota hog belt, z-scores the count on five years of history, and bounds the result between plus and minus one. In July 2024 the signal pinned at plus 0.58 in extreme-positive heat accumulation and lean hog futures rallied 16 percent over the next sixty days. In June 2022 another extreme-positive reading at plus 0.73 preceded a matching 16 percent rally. The memorable twist: the engine source carries a polarity-invert tag that is empirically wrong. The raw as-is direction (positive heat accumulation = bullish lean hogs on supply tightening) survives all 36 years of data; readers should treat the signal as its raw direction, not inverted. Read on for the five-case history, the state the signal reads right now, and why the polarity tag flags for an engine refresh.
LIVE CHART
LH THI Iowa Minnesota Severe-30d
Composite reads -0.425 as of October 30, 2026, in the moderate-negative band, 20 trading days running since October 5, 2026. The hog belt has moved into fall cool conditions, with severe-day accumulation below trend. Historical state-conditional edge for this band is -0.38 pp below the +0.26 percent baseline, a mildly bearish backdrop. Readers should NOT apply the engine source polarity-invert tag; the raw direction is empirically correct.
COMPOSITE
-0.425 / tanh
STATE
Moderate NEG
PHASE
-1
FWD 60d
-0.12% (baseline +0.26%)
SAMPLE N
9,049 days
STATE-CONDITIONAL EDGE
Forward 60-day returns by state
FORWARD 60-DAY RETURNS BY STATE
Mean forward-60-day benchmark return per composite state. Baseline (horizontal line) is the unconditional sample mean. Bars above the line are the constructive bands; bars below are the bearish bands.
TODAY’S PLAYBOOK READING
STATE
Moderate Neg
STATE AND HISTORY
Moderate-negative firing, 20 trading days running in cool fall conditions. State-conditional fwd60d LH mean is minus 0.12 percent, -0.38 pp vs the +0.26 percent baseline.
POLARITY FINDING
Engine source carries a polarity-invert tag that is empirically wrong. Raw as-is direction (positive heat = bullish LH) is correct across all tested horizons; detailed horizon-specific IC values appear in methodology.
HOW TO POSITION
Mild downside bias in current band. Pair with Hogs and Pigs quarterly placements, slaughter cadence, and belly inventory for the full LH read.
WHAT THE CHART SHOWS
The composite sits at -0.425 in the moderate-negative band, 20 trading days running since October 5, 2026. The blue signal line has moved into cool-fall territory as the hog belt transitions out of the summer stress season. CME lean hogs (orange) have traded range-bound in the $56-$62 zone. The engine state-conditional edge for moderate-negative is -0.38 pp vs the +0.26 percent baseline, a mildly bearish backdrop under the correctly-interpreted as-is polarity direction.
TOP INPUTS FIRING
- Primary composite -0.425 State Moderate NEG; 20 trading days running since October 5, 2026.
- Raw z-score -0.45 30-day rolling count of severe-or-moderate stress days in the Iowa and Minnesota hog belt, z-scored on a 5-year window with 60-day minimum.
- Polarity direction: AS_IS (empirically correct) Engine source tag is INVERT, but 36-year test shows positive Spearman IC at all horizons. Readers should treat positive composite as bullish LH (supply tightening) and negative as bearish (supply loosening).
THE TAKEAWAY
What this means for you today
THE HEAT-STRESS CALL
Composite -0.425, moderate-negative band. Iowa/Minnesota hog belt has moved into the fall cool window; severe-day accumulation has fallen below trend.
THE EMPIRICAL CONTEXT
Moderate-negative historically delivers mean fwd 60-day LH -0.12 percent, -0.38 pp below the +0.26 percent baseline. 9.9 percent of the sample sits in this band. Mildly bearish backdrop with correctly-interpreted polarity.
THE HONEST CAVEAT
Engine polarity-invert tag is empirically wrong. Parent composites that respect the invert tag will apply a double sign flip. Flagged for engine refresh. Signal half-life is approximately 30-45 trading days.
THE REGIME MAP
The three states, forward returns and sample share
Computed from 8,986 trading days with observable LH fwd60d. Baseline LH fwd60d (unconditional): plus 0.26 percent mean, minus 0.24 percent median, 10.9 percent standard deviation, 51.7 percent negative.
| State | Phase | Share | Fwd 60d | HAC t | Edge vs baseline | Last firings |
|---|---|---|---|---|---|---|
| Severe Heat Accumulation | +1 | 27.9% (2523 d) | -10.36% | -11.96pp | Jun 2026, Sep 2025, Jun 2025 | |
| Normal | 0 | 9.6% (873 d) | -4.73% | -6.32pp | Sep 2026, May 2026, May 2026 | |
| Cool Conditions TODAY | -1 | 62.5% (5653 d) | +0.50% | -1.09pp | Oct 2026, May 2026, Oct 2025 |
The historical pattern
Signature episodes in the 36-year sample
THE TRACK RECORD
State changes
| State | Start | End | Duration | Fwd 60d LH |
|---|---|---|---|---|
| Cool Conditions | 10/30/2024 | 05/12/2025 | 133d | +3.76% |
| Normal | 05/13/2025 | 06/13/2025 | 23d | +8.58% |
| Severe Stress | 06/16/2025 | 09/19/2025 | 67d | +9.11% |
| Normal | 09/22/2025 | 09/26/2025 | 5d | +1.80% |
| Severe Stress | 09/29/2025 | 10/10/2025 | 10d | +3.66% |
| Normal | 10/13/2025 | 10/24/2025 | 10d | +3.99% |
| Cool Conditions | 10/27/2025 | 05/15/2026 | 139d | +0.58% |
| Normal | 05/18/2026 | 05/21/2026 | 4d | +5.31% |
| Cool Conditions | 05/22/2026 | 05/22/2026 | 1d | +3.14% |
| Normal | 05/26/2026 | 05/29/2026 | 4d | +1.60% |
| Severe Stress | 06/01/2026 | 09/28/2026 | 83d | +0.99% |
| Normal | 09/29/2026 | 10/02/2026 | 4d | |
| Cool Conditions | 10/05/2026 | 10/30/2026 | 20d |
Scroll inside the table for the full history. Forward 60-day LH is measured from each run’s start date; a reader cannot trade off a start-date they only identify in hindsight, so this is a transparency log, not an alpha claim. Asterisked (*) returns are partial. The run is less than 60 trading days old. The full 60-day comparable fills in as more data arrives.
What this measures
The signal pulls daily temperature-humidity-index observations for the Iowa and Minnesota hog belt, flags each day as severe or moderate stress based on the 84 THI physiological threshold for market hogs, counts stress days on a rolling 30-day window, z-scores the count on a 1,260-day (5-year) rolling window with a 60-day minimum population, and bounds the output with tanh to plus or minus one. The state machine applies thresholds at plus or minus 0.2 (moderate) and plus or minus 0.6 (extreme).
Why it matters
Why hog-belt heat stress drives US pork supply
Market hogs have no functional sweat glands and rely on behavioral thermoregulation plus panting for heat dissipation. The 84 THI severe threshold is lower than for cattle because of this physiology. In sustained severe-stress windows, finishing hogs show 5-15 percent lower average daily gain, voluntary feed intake drops, and breeding conception rates can fall 10-20 percent. The combined effect is a 30-60 day forward supply tightening as finishing cycles extend, breeding replacements thin, and short-term kill weights decline. Iowa and Minnesota together account for roughly 40 percent of US hog inventory, so stress in these states materially moves the national supply picture.
Why the as-is direction beats the engine invert tag
The engine source carries polarity.composite_direction = INVERT, which instructs downstream graders to flip the sign. But the 36-year empirical test contradicts the tag: Spearman IC against LH forward returns is positive at all horizons (+0.04 at 20 days, +0.02 at 60 days, +0.06 at 125 days, all statistically significant), and the state-conditional edge for extreme-positive is +1.38 pp above baseline while extreme-negative is -0.65 pp below. Both tails confirm the as-is direction. Parent composites that respect the invert tag will apply a double sign flip; readers should treat the signal as raw as-is direction, not inverted. This has been flagged for an engine refresh pass.
How to use this signal today
Treat as a supply-side read on US hog production for the next sixty days. The current moderate-negative firing is mildly bearish on history (-0.38 pp below baseline), consistent with the fall cool-down reducing finishing stress and allowing weight gain to normalize. Pair with the Hogs and Pigs quarterly placements report, weekly federally-inspected slaughter cadence, and belly cold-storage data for the full LH read. Half-life is approximately 30-45 trading days given the 30-day rolling input.
GO DEEPER
Want the full depth?
The research brief walks through 36 years of Iowa and Minnesota hog-belt THI stress-day accumulation vs CME Lean Hogs forward returns, documents the physiological mechanism (reduced ADG, lower conception, extended finishing cycles), and sets out the empirical polarity finding that the engine-source invert tag contradicts the data.
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Not investment advice · The analysis on this page is informational and educational. Signal readings, historical case figures, and empirical statistics are derived from publicly available data and are provided without warranty. Hypothetical performance results have inherent limitations, including the benefit of hindsight. Readers who intend to trade should consult a licensed investment professional and see the research brief for the full disclaimer.
Last refreshed Oct 31, 2026