Millions of O2 customers have been unable to to make or receive calls or data since around Midday today.
The mobile phone company says it has now fixed the fault but that customers may still experience problems as full service returns.
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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."