year-to-date temperature & accumulated precipitation for the major u.s. corn & soybean states —
plus an acre-weighted national roll-up — each against its 10-year envelope (2016–2025), with the gfs
forward track refreshed daily. crop-growth stages (nass 50%-progress dates) are shaded on every chart, and a
forward yield read (enhancing / neutral / detracting) is scored from the forecast against the active stage.
temperature — daily mean
precipitation — accumulated, corn
precipitation — accumulated, soybeans
how to read · the grey envelope is the 10-year daily high–low for the selected region; the dashed grey line is
the 10y median, the thin grey line the 10y average. the solid dark line is this year's actual, updated daily.
the three ember lines are the gfs forecast — latest run, yesterday's run, and the run from five days ago; their
spread is the forecast's recent drift, summarised in the forecast-drift table under each chart.
the shaded vertical bands are crop-growth stages — calendar windows derived from the 10-year-average nass
crop-progress 50%-crossing dates; the ember-washed band is the yield-critical window (corn silking / soybean pod
set → seed fill). the yield read badges score the forward gfs window against the active stage using the
arcanum agronomy model (kdd>86°f, days>90/95°f, frost, and accumulated precip vs the 10y normal), weighted by
stage sensitivity. national is acre-weighted by current-year usda planted acres (temp + precip by total
corn+soy acres; the envelope is rebuilt from each year's acre-weighted daily series, not approximated).
source: open-meteo (era5 archive + gfs previous-runs); usda nass quick stats (acreage + stage timing).