What the conditions mean for fishing

Tide and current

Moving water carries food and pins it against structure, so it decides both where fish feed and when. Most marks fish for a couple of hours of the tide and are dead for the rest of it, and which hours those are is a property of the mark rather than of the day.

• The tide moves water, changes its depth and decides which marks can be fished.

  Strongly supported

  Tides are predicted from astronomy to the minute; the water moves whether fish respond or not.

  Read more about tide and current (1) · Read more about tide and current (2)

• Which state of tide a mark fishes best at.

  Depends on the species and the water

  A property of the mark and the species, learnt locally; no rule holds across marks.

  Read more about tide and current

What to do with it: Find out which state of tide the mark fishes before you decide what time to arrive. Fish the moving water and use slack for moving about, changing rigs and eating. Add weight or change to a grip lead when the run is strong rather than letting the bait roll.

When not to go: When the tide will cut off your way back. This is the commonest way a coastal session becomes a rescue, and it closes the exit long before it reaches where you are standing.

Wind and sea state

Wind stirs food off the bottom and pushes it downwind, which is why an onshore blow can turn a dead beach on. It also decides what you can physically fish: casting distance, bite detection and whether you can hold bottom at all.

• Wind and swell decide what can be fished safely and where a bait or lure can be held.

  Strongly supported

  Mechanical: casting, holding bottom and standing on a mark all depend on it.

  Read more about wind and sea state

• An onshore blow stirs food up and turns a beach on.

  Reported by anglers, not isolated

  Repeated by experienced sea anglers; not isolated from the season and the ground in anything read here.

  Read more about wind and sea state

What to do with it: Fish into or across the wind rather than with it if you can bear the casting, because that is where the food ends up. Drop the casting range and go heavier when it is rough. Give a beach a few hours after a blow rather than fishing it at the peak.

When not to go: When the swell is breaking over the ground you meant to stand on, or when the wind is offshore and you are afloat in anything small. Both are decisions to make in the car park rather than at the water.

Air pressure

• Falling or rising pressure changes how fish feed.

  Traditional belief, thin evidence

  Widely believed; pressure moves with wind, cloud and temperature, and no study read here separates its effect on feeding from theirs.

  Read more about air pressure

Moon phase and solunar tables

• The moon sets the size of the tide: springs around new and full moon, neaps between.

  Strongly supported

  Astronomy, and the reason a tide table changes through the month.

  Read more about moon phase and solunar tables

• Solunar tables or moon phase predict good fishing times.

  Tested, and not found to predict catches

  Quigley, Gonzalez Murcia and Kauwe (2023) compared catch rates in a recreational trout fishery with several solunar services, lunar phase and illumination: no significant relationship with any of them; air temperature predicted better. One fishery and one kind of fish — but the one controlled test read here.

  Read more about moon phase and solunar tables

No fish guide here gives the moon’s phase a conditions section of its own.

Water temperature

Fish are the temperature of the water they are in, so it sets their metabolic rate and therefore how much and how often they need to eat. It is the slowest-moving thing on this page and the one that explains most of the year.

• Water temperature sets how active a fish is and how much it needs to eat.

  Strongly supported

  Fish take the temperature of the water around them, so it sets their metabolic rate — physiology rather than angling lore.

  Read more about water temperature

• The best temperature for a given fish at a given place.

  Depends on the species and the water

  Differs by species and by population; the species pages give what is sourced.

What to do with it: Cold water: slow everything down, smaller baits, fish the warmest part of the day and the deeper water. Warm water: fish faster and earlier, and expect the fish to move shallow at the light edges rather than sit in the heat.

Water clarity and colour

It decides which sense the fish is hunting with, and therefore what a lure or bait has to do. In clear water a fish inspects before it commits; in coloured water it finds by vibration and smell and commits without looking closely.

• Clarity decides whether a fish hunts by sight, vibration or smell.

  Depends on the species and the water

  Real, and which way it cuts depends on the fish and how it feeds.

  Read more about water clarity and colour

What to do with it: Coloured water: bigger profile, more vibration, more scent, and fish closer in. Clear water: finer line, longer casts, more natural presentation, and work at the light edges instead. Change the lure to match what the fish can actually detect rather than what looks good in the box.

Nothing to look up: this is read at the water, or from the calendar.

Light and time of day

Low light shifts the advantage from the prey to the predator, which is why the light edges are the most reliably productive hours in most fishing. Artificial light does the same thing in miniature and concentrates it in one place.

• Dawn and dusk are productive for many predators.

  Depends on the species and the water

  Supported for visual predators and their prey; not true of every fish.

  Read more about light and time of day

What to do with it: Be fishing before first light rather than arriving at it. Under bright sun, fish deeper, shaded or coloured water. At night, work slower, use bigger silhouettes, and set your gear out while you can still see it.

When not to go: Anywhere at night that you have not walked in daylight first. Every hazard on a mark is the same at night and every escape route is harder to find.

River level and flow

A rising river moves fish and food and turns some swims off entirely while switching others on. A falling, clearing river after a flood is the single most reliable condition in running water.

• A rising river is higher, faster and dirtier, and changes what can be fished and waded.

  Strongly supported

  Measured at gauges and published through the day.

  Read more about river level and flow

• Heavy rain raises a river after it has fallen, by an amount and a delay that differ from river to river.

  Strongly supported

  Hydrology: rain reaches the channel through the ground and the tributaries, and the gauges record the rise as it arrives.

  Read more about river level and flow

• A falling, clearing river after a flood fishes well.

  Reported by anglers, not isolated

  Long-standing river anglers' experience; how much depends on the river and the fish.

  Read more about river level and flow

What to do with it: Fish the slacks and the inside of bends when it is high, and the creases and the faster water as it drops. Give a spate river a day after the peak rather than fishing the peak.

When not to go: When the river is still rising hard. Wading in rising coloured water is a poor bet you cannot re-read once you are in it.

The season

It is the slow background to everything else on this page. Species arrive and leave, spawning moves fish and closes fisheries, and the same mark is a different proposition in February and August.

• Which fish are present, and whether they are spawning, changes through the year.

  Strongly supported

  Migration and spawning are documented for each species; the species pages and the setup builder give the windows their sources support.

  Read more about the season

• The best month for a given fish at a given place.

  Depends on the species and the water

  Differs by coast and by year; where FishingHQ records the months catches are documented, the trip planner shows them, and it does not forecast.

• Close seasons and size limits apply in some months and places.

  Strongly supported

  Set by the fishery authority, and they change: the trip planner and the destination pages name who to ask rather than answering for them.

  Read more about the season

What to do with it: Target what is actually there rather than what you caught last time, and check the close seasons and size limits before you go — those change by fishery and by country, and FishingHQ routes you to the body that sets them rather than answering for it.

Nothing to look up: this is read at the water, or from the calendar.