The county enjoyed temperatures over 25C last week forecasters expect to see a 10C drop this Saturday and Sunday as thermometers struggle to record figures in the teens - and it could be as low as 4C overnight.
And to make matters worse, a high pollen count is expected to bring misery for those with hay fever and asthma.
Heavy showers are also forecast for Friday night and Sunday. Rain could also arrive at the start of next week.
The full Met Office forecast for Yorkshire:
This Evening and Tonight:
Outbreaks of rain spreading from the west with the some heavier bursts possible in places, especially over the Pennines. Later in the night all parts should become dry as clear spells spread eastwards. Winds decreasing in strength around midnight. Minimum temperature 4C.
The day should be dry, with good sunny spells through the morning, but cloud will tend to increase from the south during the afternoon with local rain by evening. Maximum temperature 15C.
Outlook for Sunday to Tuesday:
Sunday rather cloudy with some rain for a time, most likely across eastern areas. Sunshine and showers on Monday, these possibly heavy. Tuesday mostly dry with sunny spells.