It is very important for zoo keepers to keep an eye on the weather.
Weather is constantly changing and it affects animals of all shapes and sizes. Animals are migrating earlier, food resources are changing because food is blooming earlier, and bugs are starting to arrive earlier as well. Because of this, seeds and berries are different and simple changes like these affect everyone.
When severe weather is present, there are measures in place to keep all animals, big and small, safe. Larger animals are generally left alone so that they have plenty of room and are less likely to injure themselves. Smaller animals, like lemurs or flamingos, have specific holding cells where zoo keepers can capture, crate and move them to designated shelters safely.
Weather elements can pose problems for some animals. Most animals will act on their natural behavior. If the lemurs weren't placed in their respective holding areas on a rainy day they would go into a tree, curl up into a ball and wait out the rain. This is a problem because if they don't come down, they could miss feeding times, medication and may not be found to be brought into safety during the night. Not all animals react the same way though. Cheetahs tend to enjoy cooler weather and have adapted well to new climates because of their resilience to temperature extremes. For the most part, animals aren't much different from humans and it is typical to see an animal playing in an afternoon shower like a small child would, especially on a hot day.
Weather does not only affect animals, it affects zoo attendance; larger crowds come with good weather.