Rio de Janeiro's climate is characterized by mild winters and warm summers, with temperatures gradually increasing as the year progresses. From June to August, the coolest months, daytime highs typically reach the mid-20s to low 30s Celsius, while nighttime lows dip into the teens. Autumn (March to May) brings pleasant weather, with average highs in the mid-20s and lows around 18C. Spring (September to November) is similar, with temperatures gradually warming up towards summer. Summer itself, from December to February, is hot but not scorching, with daytime highs often reaching the mid-to-high 30s Celsius, while nighttime lows remain relatively mild.