Ronaldsway Met Office said weather conditions ahead of Saturday's Superbike Race would be cloudy and mostly dry in the morning with just the odd pocket of light rain.
However, the bulletin, issued at 5am, warned of a threat of drizzly conditions, with hill fog, increasing in the afternoon. The highest temperatures would be 16C / 61F in moderate or fresh south or south-easterly winds.
The outlook for Mad Sunday was overcast with rain, which may be heavy at times.