What's changed: Why has July been cool and unsettled?

It's certainly been a shock to our system going from the hottest June on record to a cool and unsettled July. But what's changed?

Our July has so far been dominated largely by low pressure across the UK and Ireland. Our weather pattern has changed mainly due to a change in the jet stream.

The jet stream is a fast-flowing, meandering band of air, stationed 30,000 feet high in the atmosphere and blowing west to east across the Earth. It is the result of a large temperature gradient between the northern and southern hemisphere.

In June it was sat to the north of the UK and Ireland, allowing warmer air to build in from the south. Additionally, as the jet stream is a conveyor belt for low pressure systems, it kept them out our way passing to our north, allowing high pressure to build.

In July, the jet stream shifted southwards, flowing across the UK and Ireland, carrying low pressure systems directly to us. This set-up is more akin to it's winter position, when the temperature difference is greater and the jet stream becomes stronger.

With a shift in position southwards, this also means the warm air remains contained across central and southern Europe where there is currently a severe heatwave, while dragging in cooler air to the UK and Ireland.

Temperatures have been widely around or below-average for much of the month of July, with the start of the month in particular on the cooler side.

In terms of rainfall, we have seen an increasing amount through the month, working its way wetter than average there too.

Into next week the jet stream looks to hold a similar position, so no sign of a changing weather pattern just yet. Be sure to keep tabs on our regular Weather Trends for any further detail though.