Warnings for rain ahead of a possible third heatwave

Parts of the UK could experience a third heatwave in the space of a month later this week.

Like in the previous heatwaves, parts of central and eastern England are likely to see the highest temperatures.

A number of places are likely to see temperatures exceed the 30C mark, even as far north as north-east Scotland..

June was the hottest on record across England, according to the Met Office, with statistics boosted by two heatwaves during the second half of the month.

The temperature peaked during the first heatwave with a high of 33.2C recorded at Charlwood, Surrey, on the 21 June. Little over a week later, on the 30 June both Jersey and Heathrow airports hit 33C, only to be exceed on the 1 July as Faversham, Kent reached 35.8C. Heat health alerts were issued by the UK Health Security Agency widely across England to help prepare health and social services for an expected increase in demand.

The Wimbledon Championships recorded the hottest opening day in its history as temperatures hit 32C on 30 June

Some of the heat potential is already showing up in the forecasts on your weather app and online.

It now looks less likely that changes in weather patterns to the west of the UK could disrupt the build of high pressure and southerly airflow that would help boost heat across eastern areas. Compared with last week, it now appears that heat will build more widely for a time than was initially expected.

Heat starts to build from midweek, with a many places in south-east England and east Anglia reaching their heatwave temperature threshold by Thursday. A few areas could already be reaching 30C by this time.

Temperatures will then build more widely across the UK, under south-easterly winds, by the weekend.

On Saturday, we can expect temperatures widely in the high-20s or low-30s Celsius across England, Wales and eastern Scotland. Parts of western Scotland and Northern Ireland may not get as hot, but temperatures hitting the mid-20s would still be significantly above the seasonal average.

For it to be officially classed as a heatwave, temperatures need to exceed defined threshold values for at least three days. For many of us the threshold is 25 or 26 Celsius, but for much of the Midlands, East Anglia and southeast England the threshold is higher, at 27 or 28 Celsius.

At the moment much of England, Wales and parts of Scotland will achieve those values for a run of three days or more, accompanied by increasingly warm nights too.

How long the heat will last is less clear. A quick swipe through your BBC Weather app could show the potential of a long lasting heatwave in some locations. However, low pressure developments to the west of the UK later this weekend may bring a incursion of less hot Atlantic air for the early part of next week. This may be only provide a temporary lull in the heat across some southern and eastern areas though. Heat across other parts of western Europe may creep back in here later in the week.

Three heatwaves so early in the summer, and a lack of rainfall too is causing concern over what is to come through the rest of the season. Climate scientists are warning that frequent, more prolonged heatwaves are more likely due to human-induced climate change.

As ever, your BBC Weather team will keep you updated throughout.