What Factors Affect the Weather?

It’s one of Brits’ favourite talking points… but what actually controls it?

Whether it’s too hot, too cold, too wet, or “not like it used to be,” the weather is a daily topic of conversation in the UK.

But behind every grey sky or surprise sunny spell, there are a number of factors working together to create what we experience outside.

Here’s what really affects the weather.

☀️ 1. The Sun (it all starts here)

The biggest influence on our weather is the sun.

It heats the Earth unevenly, which creates differences in temperature across the planet. These temperature differences are what drive wind, pressure systems and, ultimately, weather patterns.

That’s why summer feels different to winter. The angle and intensity of sunlight changes throughout the year.

🌍 2. Air pressure systems

You’ll often hear about “high pressure” and “low pressure” on forecasts, and they make a big difference.

High pressure usually brings settled, calm weather. In the UK, that often means dry conditions and clear skies
Low pressure brings unsettled weather, including cloud, wind and rain

The constant movement of these systems across the UK is a big reason why our weather changes so often.

💨 3. Wind

Wind is simply air moving from high pressure to low pressure.

But it also determines where our weather comes from:

Winds from the Atlantic tend to bring mild, wet conditions
Winds from the continent can bring hotter summers or colder winters
Northern winds often bring colder air

In the UK, wind direction can completely change how a day feels.

🌊 4. The sea (a big UK influence)

Being surrounded by water has a huge impact on British weather.

The Atlantic Ocean helps keep temperatures milder than they would otherwise be. It also brings a lot of moisture, which is why we see so much cloud and rain.

Ocean currents, like the Gulf Stream, also play a role in keeping the UK warmer than similar locations further north.

⛰️ 5. Geography and landscape

The shape of the land matters more than you might think.

Hills and mountains force air to rise, which can lead to more rainfall
Coastal areas often have milder temperatures
Cities can be slightly warmer due to built-up areas retaining heat

This is why the weather can be completely different just a short drive away.

🌡️ 6. Temperature differences

Weather is driven by contrasts.

When warm and cold air masses meet, you often get unsettled conditions like rain or storms. When temperatures are more stable, the weather tends to be calmer.

These differences are constantly shifting, which is why forecasts can change.

☁️ 7. Humidity and moisture

Humidity is the amount of water vapour in the air.

High humidity can lead to:

Cloud formation
Rain
That “sticky” feeling in warmer weather

Low humidity usually means clearer, drier conditions.

🌪️ 8. Jet streams

The jet stream is a fast-moving band of air high in the atmosphere that helps steer weather systems.

In the UK, its position can make a huge difference:

If it sits to the north, we often get more settled weather
If it moves south, it can bring a run of wet and windy conditions

It’s one of the reasons forecasts can change quickly.

🔄 Why UK weather feels so unpredictable

All of these factors are constantly interacting.

Because the UK sits between the Atlantic Ocean and continental Europe, we’re right in the middle of competing influences. That means weather systems can change quickly and often.

One day it’s sunny, the next it’s raining, and sometimes it’s both in the same afternoon.

The bottom line

Weather might feel random at times, but it’s actually the result of several key factors working together.

From the sun and the sea to pressure systems and wind direction, everything plays a part in what you see when you step outside.

So next time you’re talking about the weather… you’ll know there’s a lot more going on behind it.