Water temperature and the seasons

Water heats and cools far more slowly than air, so the Bay is still cold in April when the afternoons feel like summer, and still warm in October when the mornings feel like fall. Fish move on the water's schedule. That is why this guide's seasons are broad bands rather than dates, and why a warm October or a cold snap makes them read early or late.

As the lower Bay warms, the migratory species arrive in a rough order that the Chesapeake Bay Program's field guide documents: croaker move through the Bay from March, spot from April or May, speckled trout visit from April, red drum and cobia from May. In the reservoirs, bass and crappie spawn on the same cue. The order is dependable; the dates move with the water.

Cooling water concentrates bait along the beaches, piers, and inlets, and fish feed hard before they leave — the reason many anglers call fall the most consistent stretch of the year. Striped bass move in as the Bay cools, tautog come back onto the structure, and trout push into the creeks and then, as it gets colder, into the deep holes.

NOAA's water-temperature stations report it directly, and four Bite Windows spots — the ones whose tide station also carries the sensor — show the latest reading. NOAA's buoys report nearshore and offshore temperatures. Everywhere else, the Bay-wide pattern is the honest answer, and the number at a nearby station is a better guide than the air temperature outside your door.