West Nile Virus (WNV) is a potentially serious illness. Experts believe WNV is a seasonal epidemic of the summer months, just like influenza is to winter. West Nile Virus can be transmitted year-round whenever mosquitoes are biting, which is why it is best to protect yourself all year.
Prevention is a key component. There is no way to predict what a mosquito season will be like, which means that everyone needs to do what they can to eliminate breeding sites around their homes, as well as use repellent and dress appropriately if they are outdoors whereever mosquitoes are most active.