The Slough has abundant wildlife and birds year-round but since you asked: Spring and fall will bring more abundant birds as they migrate. Spring will also bring green hills, wildflowers and baby animals such as sea otters, harbor seals and nesting birds. Summer is great time to visit and escape the heat of the Bay Area. Fall is a wonderful time of year as well with abundant birds, sea otters, harbor seals and perhaps more baby otters. We also love the weather in the fall – typically the fog of summer lifts and we enjoy a week or two of beautiful weather before winter rains arrive. Our winters are marked by breathtaking sunsets, but it’s harder to plan ahead for clear weather.