Seasonal variation has nothing to do with it. The change happened either at the beginning of Autumn, when lots of food should be produced, or the end of Summer when the "normal" amount of food should be produced.
Autumn started two days ago on FEI, and multiple weather areas are experiencing poor weather right now. (As an aside, the worst time to have poor weather is Autumn)
The 25% surplus is targeted across all seasons and ignores weather.
