Harvest season for winter wheat should already be underway in Texas. (Winter wheat is planted in late summer or early autumn, grows green like the grass it is, then goes dormant through the winter, reviving and producing tiny flowers in the spring, followed by seed which first swells then dries hard.)
Harvesters will, in recent weeks, have been assembling and preparing equipment and crews, firming up agreements with farmers and attempting to fill any large gaps in their schedules.
They'll be moving north with the tide of ripening wheat, clipping seed heads from stalks and threshing them in a single operation, in field after field, working first for one farmer, then another, then another, each one generally located further north than the last.
On highways you'll frequently see their large combine harvesters go by on trailers, with their headers (the wide cross-piece that mounts on the front of the machine) either nestled in the backs of the trucks they'll use to haul the grain to shipping/storage facilities (elevators) or towed separately.
It happens every year, beginning about this time, a great parade, hundreds of miles wide, passing from south to north over a period of two or three months and lasting about two weeks as it passes by any point along the way. With it comes the smell and fine airborne grit of pulverized wheat stalks, the sound of engines, and a general bustle, partly owing to the harvest activity itself and partly to the temporarily swollen populations of otherwise sedate rural communities.
Rain, particularly a storm which brings several days of drizzle over a large area, can slow harvest activity to a halt, both because the combines easily bog down in wet fields and because the grain must be dry (around 14% moisture content) when it goes into storage. Rain means downtime, which some may use to make a quick run to a home hundreds of miles away, while others will stay close, to be ready for a break in the weather. Rain means new faces in what few bars there are and a subdued party atmosphere, kept in check partly by the knowledge that crew bosses have little patience for hangover-induced imprecision in handling harvest equipment, which can cause extra time in a field, cleaning up bits that were missed on the first pass or unnecessary downtime to clear a header of dirt scooped from a terrace, or worse.
Sometimes particular fields won't have dried out sufficiently by the time the harvesters have moved on, and farmers who own their own combines may end up spending another couple of weeks cutting these.
Occasionally a field never does dry out, and the crop sprouts on the stalk, or rots before it can be harvested. Savvy farmers replant such fields to something other than wheat.