Monthly Outlook

Temperatures will gradually come down into the coming week, easing closer to seasonal levels as the weather becomes wetter. However, drier and warmer weather may return around and after mid-June.

Turning cooler and unsettled

The first week of June should become unsettled as the strong high pressure block that brought such high temperatures declines, allowing a series of Atlantic low pressure and frontal systems to move near or across the UK.

This will bring periods of wet and windy weather, with some heavy rain or showers possible at times, and rainfall is likely to be above-average for the time of year. However, the north-west might see the brunt of the rain, with the south-east less wet.

As a result, a cooler week lies ahead. Temperatures should still reach the mid to upper 20s Celsius in central, southern and south-east England on Saturday, but Sunday will see some moderation, with further day-to-day decreases coming as temperatures trend towards more seasonal values for a few days.

There is a slight risk that even cooler air could move across, particularly into Scotland, in between frontal systems, and especially if the low pressure track turns out to be farther south.

However, the end of the week might see high pressure start to rebuild, with temperatures potentially beginning to rise again, at least across southern regions.

Warming above average in many areas

The most likely outcome in the second week of June is for high pressure to strengthen over the European mainland and try to expand northwards towards the UK.

This should start to push the main frontal boundary farther north, with drier-than-normal conditions developing, at least across much of England, Wales and Northern Ireland.

Some rainfall cannot be ruled out anywhere, but parts of Scotland could remain wetter, especially the north and west. Rainfall could be above average here, with temperatures suppressed.

Most other areas should shake out warmer than normal, and there could be a chance of one or two days warming to the mid to upper 20s in some central and southern regions of the UK.

The risk to this forecast is for a different alignment of high pressure - to the west or north - bringing some cooler flows, and that has about a 25% chance.

It could be warm and mostly dry in many areas

After the middle of June, it looks like high pressure could nudge farther north and become settled across the UK.

This should promote warm conditions with temperatures above the early-summer average in most areas, aside from places with onshore winds. It should also be drier than normal, and that might help to trigger stronger heat spikes at times.

There is a possibility that pressure may also build across Scandinavia later, reinforcing warmer flows; and if high pressure weakens or nudges northwards across the UK then the door could open sufficiently for low pressure systems to creep in from the south.

This would bring an increasing chance of heavy showers and thunderstorms spreading northwards by the end of June.

Again, the exact position of the expected high pressure remains important: if it were to become centred farther north, north-west, or west as one forecast model suggests, then cooler weather would be possible, and that is estimated to be about a 30% risk.

In Tuesday's update we might expect to solidify the temperature trends through the next couple of weeks, if the forecast position of high pressure circulations remains consistent.