For a 2026 visit to Disneyland, September is significantly better than August for both crowds and weather. August is typically one of the hottest months in Southern California, with temperatures frequently reaching the 90s°F (32°C+), and it remains busy as families squeeze in their final summer vacations. In contrast, once Labor Day passes in early September, the crowds drop noticeably as schools return to session. September also marks the start of the Halloween Time season, which brings festive decorations, themed treats, and the popular Haunted Mansion Holiday overlay. While you might encounter some "blocked out" dates for lower-tier passholders in September, the "standby" wait times are generally the lowest of the year during the mid-week periods. If you can handle the slight risk of shorter park hours due to "Oogie Boogie Bash" events on select nights, the cooler mornings and shorter lines make September the clear winner for a more relaxed Disney experience.