How does the weather affect fishing?

Fish lexicon

Biting behavior of the fish: Influences of the moon, air pressure and light intensity

Effects of the full moon

The influence of our moon has undoubtedly a great influence on our planet: starting with the formation of the tides, through the planting times in agriculture, to the spawning migrations of certain species of animals.

Some of our fish are also very sensitive to the moon. The effect of the full moon phase on predatory fish in particular is extremely interesting.

As the catch statistics of many anglers show, particularly large predatory fish are extremely active in the full moon phase. We cannot explain why this is so. Maybe it's the changed attraction or the brighter night.

There is, however, an undisputed connection between the feeding activity of large predatory fish and the full moon. As already mentioned, this phenomenon particularly affects large predatory fish such as pikeperch, pike and catfish.

Only the eels seem to shy away from the full moon, because they don't seem to like the bright light of the full moon.

It is also noticeable that in the time of the full moon (approx. 3 days before to 1 day after the full moon), although many large predators show increased feeding activities, the small and medium-sized specimens bite extremely cautiously (low bite frequency).

Further information on full moon times can be found on our page [Weather and moon phases] in the service area.

Air pressure and biting behavior

The weather over water plays a crucial role in the activity of the fish. Changes in air pressure in particular have an extreme effect on our predators, be it positive or negative.

The value of the atmospheric pressure is measured in hectopascals (hPa), whereby the standard value is approx. 1013 hPa. In an average low-pressure area, this value drops by approx. 10 hPa to 1003 hPa. In a high-pressure area, this value increases by approx. 10 hPa to 1023 hPa.

Low pressure areas usually cause a worsening of the weather and bring cloudiness and rain, whereas high pressure areas cause better weather with sunshine. Accordingly, even small changes are sufficient
the air pressure to cause a change in the weather.

Our fish are also extremely sensitive to changes in air pressure. Especially predators like pikeperch
and perch will lose your appetite when the air pressure changes. Constant air pressure, on the other hand, has an extremely positive effect on the eating activities of our fish.

The reasons for this are as follows: In contrast to the cyprinids, pikeperch do not have the opportunity to
to regulate compensation via the digestive tract. The predators therefore have to compensate for any change in pressure in their swim bladder with the blood. Since this process puts the predators under stress and also lasts for a long time, food intake is very low during this time.

A change in air pressure also changes the oxygen saturation in the water: the higher the atmospheric air pressure, the more oxygen the water can absorb. On the other hand, if it falls, the oxygen saturation in the water is lower. These changes mean that our fish first have to get used to the new oxygen conditions before they can eat again.

Basically, the following rule applies: constant air pressure conditions over 3 days or longer apply because of favorable conditions for fishing. When fishing for predatory fish, many prefer constant low pressure areas with cloudy skies and rain showers, as our predators generally shy away from bright light.

Light intensity

Many of us should know that you can enjoy a wonderful sunny day with a mirror-smooth water surface.
area must not expect any predatory fish that are eager to bite. They know from experience that the light that penetrates the water on these days makes them visible to the prey fish and that the hunt is therefore not worthwhile.

However, if a steady wind blows over the water, some of the sun's rays are reflected from the surface of the water and the likelihood of outsmarting a predator increases again. It is the same in the morning and evening hours (even in winter) when the sun is low, as the light conditions for our predators are again favorable.

Not only the weather but also the seasons influence these lighting conditions: in winter the fish bite quite well during the day, while in the summer months they prefer the twilight hours. But why is this so?

The light intensity is measured in the unit lux. 1 lux corresponds to the brightness of a candle from a distance of 1 meter. On a bright sunny day in summer, this light intensity is around 100,000 lux, but on an overcast winter day it is only around 3,500 lux (full moon night: around 0.25 lux). It is precisely this small amount of light that offers our predators considerable advantages when hunting.


"Moon phase, air pressure and light intensity", Birger Domeyer, Fisch & Fang 01.2011.

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