The CITY is set for “plenty of sunshine” in the coming days, but the dry weather will also contribute to high levels of air pollution.

Forecasters say today has already been the warmest day of the year so far with the mercury with highs of 20.5C recorded in Northolt, west London.

The conditions are set to be dry and sunny in Brighton and Hove for the next few days before colder, wetter conditions return next week, according to the Met Office.

The Argus: Brighton and Hove has been basking in sunshine this weekBrighton and Hove has been basking in sunshine this week

However, experts also say that south-easterly winds are blowing pollutants in from Europe and the settled UK weather is contributing a build-up of “high levels of air pollution” – especially in towns and cities.

The UK Health Security Agency (UKHSA) is advising people to “reduce physical exertion” in areas that are particularly affected and those with lung or heart problems to “avoid strenuous physical activity”.

A UKHSA spokesperson said: “Many parts of the country have recorded/are forecast to have very high levels of ambient air pollution.

“UKHSA is advising people in those areas to reduce physical exertion, particularly when outdoors and especially if they experience symptoms such as a cough or sore throat.”

“Adults and children with lung problems, adults with heart problems, and older people, in areas where high levels are recorded should avoid strenuous physical activity.

“People with asthma may find they need to use their reliever inhaler more often.”

Becky Mitchell, senior operational meteorologist at the Met Office, said: “Temperatures are rising quite quickly and there’s plenty of sunshine across the whole country today.

“Most places are staying dry and sunny and it looks very similar for much of this week – we hang on to that sunshine.”

The toastiest two days of the current sunny spell will be today and Wednesday, when temperatures are forecast to be 20C.

Becky said: “As we head into next week, it will probably start off sunny and dry, but we’re likely to start to see some showers as the week goes on.

“It will be turning a little bit more unsettled and also, it will be a little bit colder as well.”