Following warm and sunny weekend weather, St Albans is set for a heatwave by the end of this week.

After temperatures in the mid 20s throughout Saturday, August 6 and Sunday, August 7 in Hertfordshire, the Met Office forecasts highs of 31C in St Albans by Friday, August 12.

The hot weather follows a dry July, with warnings that the current conditions could adversely impact railways and the water network.

A heatwave is defined as three consecutive days when the temperature exceeds 28C in Hertfordshire - although the temperature threshold varies by county.

Herts Advertiser: Dry grass on Windmill Hill in Hitchin, Hertfordshire on August 6, 2022Dry grass on Windmill Hill in Hitchin, Hertfordshire on August 6, 2022 (Image: Will Durrant)

The Met Office long-range forecast for the period Thursday, August 11 until Saturday, August 20 reads: "Temperatures are expected to continue above average, becoming very warm or hot in the south.

"Into the weekend and through next week, mainly dry and settled weather will likely continue for most.

"The north is expected to see the most of any precipitation, but there is also a low risk of thunderstorms developing in the south."

St Albans is set for sunshine on Monday and Tuesday this week (August 8 and 9) with 27C highs.

The mercury is set to hit 28C on Wednesday, before rising to 31C by Friday.

Night-time temperature lows are due to sit around the 14C and 15C mark until Wednesday, rising to 17C on the weekend.

Herts Advertiser: An unseasonably empty Verulamium Park, St Albans on July 19, 2022 - the hottest day ever recorded in the UKAn unseasonably empty Verulamium Park, St Albans on July 19, 2022 - the hottest day ever recorded in the UK (Image: Will Durrant)

According to East Anglian forecaster Dan Holley, of Weatherquest, last month (July) was the driest on record for the region - with just 1.2 rain days.

This compares with 2.1 rain days in 1955, 2.2 in 2021 and 3.2 in 1977.

A new hottest temperature record for Hertfordshire was set on July 19 in Buntingford, East Herts at 39.2C, beating the previous 37.9C record set at Aldenham, near Watford on August 10, 2003.

Herts Advertiser: Sunbathers enjoy the hot weather in Hyde Park, London on Saturday, August 6Sunbathers enjoy the hot weather in Hyde Park, London on Saturday, August 6 (Image: Beresford Hodge/PA Wire/PA Images)

On the railways, Network Rail has warned it may need to introduce speed restrictions if drought impacts the soil beneath the rails, or if hot rails are at risk of expanding and "buckling".

A spokesperson said: "Hot weather can affect the rails, overhead power lines and the ground which the track sits on.

"We work hard to get you to where you need to go, safely and on time by minimising the impact of hot weather on the railway."

A spokesperson for Affinity Water, which supplies water in St Albans and much of Hertfordshire, said groundwater levels are "below average".

They said: "During autumn and winter last year, there wasn't as much rainfall as normal, so our groundwater levels are below average.

"There are no current restrictions, but it's important to use water wisely."

They added that water customers should follow steps to stop Affinity Water being left "high and dry" (https://www.affinitywater.co.uk/our-water-resources).

These include avoiding hosepipe use, turning off the tap while brushing teeth, and filling up washing machines before turning them on instead of running half washes.