There is never a “bad” time to visit Disneyland, but some prefer to visit while the crowds are at the lowest. This allows people with limited time to see and do more in the park. The southern California area has a lot of locals with season pass holders, so weekends are always going to be very crowded, no matter what time of year you visit. Another factor in Disneyland crowds is the Anaheim Convention Center right across the street. Many people attending a convention here pop by Disneyland before or after their convention. It’s usually not necessary to rearrange your Disneyland vacation plans based on convention schedules, but there is one to note this year: Disney’s D23 Expo (dubbed the “Ultimate Disney Fan Event”) which will be at the Anaheim Convention center on July 14-16, 2017. This will make for uber crowds that week!
I’ve created the crowd calendar below based on research of crowd predictions in 2017.