Weather will likely play an important role when you plan your trip to Warrenton, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July, with an average temperature of 15°C, while the coldest months are February and December, with an average of 7°C. The rainiest months in Warrenton are November, December, January and March, with each month seeing an average of 236 mm of rainfall.