The cold and influenza season will reach full force in a few weeks, according to the Benylin forecasting centre.
The UK as a whole is now classified as being at the "pre-alert" stage and will proceed to "alert" status in three to five weeks. The alert stage lasts eight to 10 weeks and indicates a peak in respiratory illnesses, with up to 77 per cent of households affected.
According to the forecasting centre, Bristol, Leeds and Norwich are the furthest advanced in the season, having been at pre-alert status for three to four weeks, while other cities across the UK (including London and Glasgow) have not yet reached pre-alert status.