Around 100 protesters, believed to be English Defence League supporters, are holding unplanned protests in two areas of Manchester.
There are also reports of a counter-protest by members of Unite Against Fascism in another part of the city.
Greater Manchester police have told ITV Granada that one person has been arrested on suspicion of a public order offence.
More top news
At times a little fair weather cloud may bubble up - and there will be a fairly brisk southeasterly breeze - but it will still feel hot.
Analysis of data from hospitals in England showed patients were waiting longer for ambulances, treatment and admission.
She told reporters: "I don't think it's fully sunk in how really bad that could have been, I know it's not the right decision."