St Louis has a continental climate that swings hard — humid summers in the high 30s, winters that drop well below freezing. The best months are April to early June and mid-September to late October, when temperatures sit in a comfortable 15 to 25°C range. Spring brings the dogwoods and the Cherokee Street Cinco de Mayo festival; autumn has milder weather, baseball at Busch Stadium, and the foliage along the Mississippi bluffs.
July and August are uncomfortably hot and humid; locals retreat indoors or to Forest Park's shaded paths. Mardi Gras in Soulard each February is a winter highlight if you don't mind cold weather. The Muny opens its summer musical season in late June and runs through mid-August — a hot but iconic St Louis evening out.