Generally, pecans are ripe enough to harvest between October and January in the southern half of the United States. However, the exact month depends on the state and the climate.
For instance, pecan harvesting in Arizona usually begins near the end of November and ends in January. However, in Georgia, the harvest begins a bit earlier in October and runs to December. Texas pecans can also be harvested as early as October, especially in the southern parts of the state, though the harvesting date can also be later. Like Arizona, the harvest can begin as late as the middle of November.