0C–7.2C model — counts hours where the temperature is between 0 °C and 7.2 °C (32–45 °F), 1 Nov – 1 Apr.
Richardson (Utah) — weights each hour by temperature band (including negative weights for warm hours); accumulation begins after the season’s most-negative running total (inception).
Mainland — weighted units with negation for warm hours; after 800 units, hours ≥ 12.8 °C (55 °F) stop negating; the model ends 28 Feb.
Bars in the table view are scaled to a 1,200-unit reference.