An important part of a successful theme park visit is making sure you and those you are traveling with (in my case, my husband and 2 kids) are comfortable. Otherwise you’re going to be hearing a lot of complaining about being too cold/hot/wet/whatever and that can really ruin a good time!
Overall, the weather in Anaheim is really mild and pleasant. The mornings and evenings are pretty brisk all year long and the afternoons are sunny and warm. That being said, weather can be unpredictable so you want to make sure you check the forecast ahead of time so you know what to expect. In general, the monthly averages look like this: