Weather is probably a major factor when you plan your trip to Surrey Hills, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually February and January, with an average temperature of 7°C, while the coldest months are July and August, with an average of -3°C. The rainiest months in Surrey Hills are May, September, December and July, with each month seeing an average of 360 mm of rainfall.