In this chapter, we consider how adverse weather conditions such as rain or fog affect the performance of wireless networks, and how to optimize these networks so as to make them robust to these conditions. We first show how to analyze the weather conditions in order to make them useful for network optimization modelling. Using an example realistic network, we show how to optimize two types of wireless networks: free-space optical (FSO) networks and wireless mesh networks (WMN). The key difference between the two network types is that in WMNs, links interfere with each other, while in FSO networks, link rates may be assumed independent. We formulate optimization problems to protect each network type against adverse weather conditions, discuss solution methods to solve them and present a numerical study illustrating the considerations of the chapter.