Experts have said that the combo of long winter and an early summer may send pollen levels rocketing and this could cause health problems in many people.
'The cold spring meant a late start for pollen, with pollen burst now in a condensed period - and the phenomenon of several pollens likely to peak at the same time. There's a chance of overnight frosts with -1c to -3c lows, mainly in the North,' researchers said.
Forecaster Brian Gaze of The Weather Outlook said: 'It looks like turning much colder later in the week, with a very late season Arctic blast bringing frost and the risk of snow in central and northern regions of the UK.'
People prone to allergy must take adequate care to protect themselves - for instance keeping themselves covered, washing face and hands frequently, to prevent falling sick due to hay fever.