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We're officially in autumn, and one thing lots of people associate this season with is the changing colours of the leaves.

But the National Trust, which works to protect the natural environment across England, Wales and Northern Ireland, says our wet and cool year so far means trees will hold onto their leaves for longer this autumn.

The most colourful autumn leaves develop when we have sunny days and cool nights.

But the organisation says they still have hope for a dazzling display of oranges, yellows and reds if the weather settles.

Why do leaves turn brown in autumn?

For trees to grow, they need three things - sunlight, nutrients and water.

In the summer months, leaves use a chemical called chlorophyll to capture sunlight. This is what makes them green.

The chlorophyll turns the sunlight into food for the tree and it helps trees grow. The food they make is sugar and it's used to grow new leaves, flowers and seeds - a process called photosynthesis.

As autumn arrives, the days get shorter, it gets colder and there is less sunshine for the leaves to make food with.

When trees realise that winter is about to begin, they start breaking down the chlorophyll (green) that is stored in the leaves to get the nutrients out.

This allows trees to store all the nutrients from their leaves in their roots, which are protected from the cold during the winter months.

As the plants break down, the chlorophyll green colour disappears from the leaves, leaving behind other colours you normally can't see.

Some trees shed their dead brown leaves because they are no longer able to get energy from them through winter.

By shedding their leaves, trees are able to survive because they make room for new growth in the spring.

What's happening to the leaves this autumn?

Sunny days and cool nights make for the most colourful displays.

But we've had a lot of rain this year, meaning the trees are holding onto their leaves for longer, and the National Trust said this could have consequences if the weather doesn't settle down.

Pamela Smith from the charity said: "As the predictability of weather patterns continues to alter due to a changing climate, the timings of a traditional autumn with its colourful canopy displays become less certain.

"We've seen a real mixed bag of conditions so far this year - particularly the soggy start, but if we see a gradual drop in temperature along with more settled weather, we could expect to see a drawn-out display.

"However, if we get sharp, hard frosts or see further wet weather with storms, heavy rain and wind roll across the UK, that may cut any extended show short.

"No matter how this season unfolds, we are already seeing signs that things are getting under way around the country, whether that's in a city, town or in the countryside."