Weather is probably a major factor when you plan your trip to Lajeado, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually January and February with an average temp of 74°F, while the coldest months are July and June with an average of 58°F. The rainiest months in Lajeado are October, September, July, and January, with each month seeing an average of 7 inches of rainfall.