Planning for the weather is a good way to make your trip to Girvan relaxing and enjoyable, especially when you’re splurging. The hottest months are usually August and July, with an average temperature of 14°C, while the coldest months are February and January, with an average of 7°C. The rainiest months in Girvan are December, October, November and January, with each month seeing an average of 214 mm of rainfall.