Parts of the UK are set to experience a mini heatwave with temperatures rising to 30C.
The hot weather comes after well above-average rainfall figures in the first half of the month, including a weather warning for rain on Tuesday evening.
However, by Friday, temperatures in London and the South East could reach 30C before milder conditions return on Sunday.
Met Office spokesperson Nicola Maxey said night-time temperatures could stay in the low 20s for parts of south-east England – officially classified as “tropical nights” if they do not drop below 20C – with there being health implications for the elderly or infirm.
She said there was still uncertainty over how soon the milder conditions would come in, with the possibility that the South East could retain its heat a little longer than elsewhere.
Meanwhile, parts of the country have already well-exceeded July’s average rainfall figures despite only being halfway through the month.
The Met Office spokesperson said England had 97% of July’s average rainfall between July 1 and 15, Wales had 65%, Scotland 49% and Northern Ireland 47%.
London has had 154% of its July average already and Dorset 120%. Edinburgh has only had 40% and Dundee 33%.
Ms Maxey said: “There are quite big regional differences but overall it’s looking like a wet month so far.
“There is a caveat that, with a dry couple of weeks, by the end of the month things could even themselves out.”
She said that two or three heavy downpours often caused much of a location’s July rainfall totals, rather than a prolonged period of wet weather.
St Swithin’s Day on Monday – traditionally said to predict the next 40 days of weather – was another wet one for much of England and Wales.
But the Met Office said conditions next week would be “changeable” rather than just rainy, with temperatures close to average.