Indianapolis experiences a humid continental climate, characterized by four distinct seasons: hot, humid summers; cold winters; and transitional periods in spring and autumn.
Seasonal Breakdown
Summer
Summers in Indianapolis are warm and humid, with average high temperatures in July reaching around 85°F (29°C). The season typically spans from late May to mid-September, offering ample sunshine and occasional rainfall.
Winter
Winters are cold, with average January temperatures hovering around 28°F (-2°C). Snowfall is common, averaging approximately 23 inches annually.
Spring and Autumn
Spring and autumn serve as transitional seasons, featuring moderate temperatures and varying weather patterns. Spring often brings increased rainfall, while autumn is marked by cooler temperatures and vibrant foliage.
Climate Change Impacts
Recent studies indicate that Indianapolis is experiencing more frequent and intense heat streaks. For instance, in 2025, the city endured its fourth heat streak by July, an eight-day event with temperatures exceeding the 90th percentile for the area.
Additionally, rainfall intensity has increased by approximately 14.6% from 1970 to 2024, leading to more severe storms and heightened flood risks.
Understanding these patterns is crucial for residents and policymakers to adapt and mitigate the effects of a changing climate.