A yellow weather warning for thunderstorms has been issued for parts of East Lancashire.
The Met Office has said that thunderstorms will be developing across northern England and Scotland may cause disruption and localised flooding on Sunday afternoon and evening.
The warnings have been put in place for Blackburn, Burnley and surrounding areas from about 1pm, when temperatures are set to hit 26C, before rain brings in cooler temperatures, seeing the mercury drop to 20C after 2pm.
The rest of the afternoon and evening is expected to remain dry.
The Met Office website states: "A largely dry and bright start before cloud thickens from the west with a strengthening breeze.
"Outbreaks of rain, locally heavy and thundery at times gradually moves eastwards with some showers following behind. Maximum temperature 27C."
The forecaster warns where storms hit there is a small chance of flooding and damage to buildings by water, wind or lightning strikes.
There could also be a chance of delays to public transport and rain could lead to difficult road conditions, while there is also the chance of a loss of power.
The Chief Forecaster added: "Thunderstorms will develop in some places, from early afternoon, as cooler conditions follow from the west.
"There is a chance an organised line of thunderstorms could develop across northern Britain during Sunday afternoon before clearing east into the North Sea during the evening.
"This is more likely to happen across eastern parts of the warning area including northeast England and eastern Scotland.
"Rainfall amounts will vary significantly, but some locations could see 30 to 40mm in one or two hours.
"Frequent lightning, large hail (up to 3cm in diameter) and strong, gusty winds will be additional hazards."
Tonight will see cloud breaking to leave some late sunshine though perhaps with the odd shower.
The outlook for Monday includes sunny spells with scattered showers with cooler temperatures of around 20C.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here