Cleveland's climate is largely influenced by Lake Erie: It's cooler in summer and more moderate in winter than its latitude might suggest. (Just the same, lake-effect snow often buries the city.) Although some summer days can be hot (90+ F/32+ C) with high humidity, the usual summer temperatures are 57-81 F/14-27 C. When breezes blow from the lake, temperatures stay comfortable. Spring has the most rainy days, and thunderstorms occur most frequently in June and July. The best times to visit are late spring and autumn: Temperatures range 47-68 F/8-19 C in May and 43-74 F/6-22 C in September and October.
Most attractions are open year-round, although some outdoor activities and lakeside attractions close during winter. Temperatures are often well below freezing in the cold-weather months, but they're not extreme (18 to 32 F/-5 to 0 C are January ranges). A wind off Lake Erie can make it feel much colder.