Best times to fish
Time of day
Early morning and late afternoon/evening are consistently the most productive windows, especially in summer when the middle of the day gets too warm and bright for many species to feed actively near the surface. In winter this shifts slightly, with a milder late morning often outperforming a cold dawn. Dawn and dusk line up with natural insect activity and lower light levels that many fish, particularly predators, use to hunt.
Barometric pressure
Stable pressure, in the range of roughly 29.70-30.40 inHg, tends to mean settled fish behaviour and reliable feeding, regardless of whether that stable pressure is high or low. What actually disrupts fishing is rapid change: a sharp pressure drop ahead of a storm often triggers a short, intense feeding spell, while the 24-48 hours after a sharp cold front (pressure rising fast, temperature falling fast) is one of the most reliably slow periods in UK fishing. If you can check a forecast before choosing a day, a front's after-effects are worth avoiding more than any single "good" or "bad" weather type.
Weather conditions
Mild temperatures, partly cloudy skies and stable pressure are the closest thing to an ideal combination. Heavy rain and strong wind both genuinely reduce sport, not because fish stop existing but because they typically feed less predictably and are harder to present a bait to in disturbed water. A light breeze putting ripple on still water is often helpful, since it breaks up the surface and reduces a fish's ability to see movement on the bank.
Season by season
Spring (post-close-season, from 16 June for rivers): fish are actively feeding after spawning, a strong time for most coarse species. Summer: early and late in the day beat the heat of midday; carp and other warm-water species are at their most active. Autumn: pike and other predators become considerably more active as they feed up before winter, making this the strongest predator-fishing window. Winter: fish feed less and more cautiously in cold water, favouring smaller baits, finer tackle and a milder part of the day over an early start.