Climate and monthly weather forecast
Indiana, USA

Indiana experiences a humid continental type of climate (Köppen climate classification Dfa, Dfb) in the northern and central regions of the state and a humid subtropical climate (Köppen Cfa) in the south. Hot summers and cold winters are typical, with a gradual increase in warmth in the southern regions. Indiana lies in the Midwestern and Great Lakes region of North America. Ohio in the west, Kentucky in the south and southeast, Illinois in the west, Lake Michigan in the northwest, and Michigan in the north, border the state. Location in the continent, scarcity of high mountain ranges, and the Gulf of Mexico are major players that influence the climate.

Indiana, the Hoosier State, has an average elevation of 210 meters above sea level, with the highest point at Hoosier Hill at 383 meters. The topography mainly consists of flat plains in the northern two-thirds, and hills, caves, ridges, and waterfalls in the south. Indiana comprises of two natural regions: the Central Lowlands and the Interior Low Plateaus of the United States. Along the Lake Michigan shoreline, there are sand ridges and dunes in the northwest. The central region is mainly flat, and the soil is favorable for agriculture. The Hoosier National Forest and much of southcentral Indiana has rugged, hilly terrain.

The best time to visit Indiana is in the autumn season from September and October when the temperatures are pleasant, and the skies are clear. The sunny days register temperatures in the 65°F (18.3°C) to 85°F (29.4°C) zone, while the nights are in the range of 40°F (4.4°C) to 60°F (15.6°C).
The rainfall ceases significantly from the high of summer and is light to moderate. Storm activity eases considerably by the end of September, and the season is the most colorful time of the year. Summers are hot and humid in Indiana and the time of peak tourist activity. Fall trips are more economical than in the summer.

The worst time to visit Indiana is from December to February when the state lies in the grip of severe cold weather. Low temperatures often drop to extremes that can reach 0°F (-17.8°C) as strong wind speeds keep the conditions chilly. Polar air masses frequently invade the northern regions and even affect the south to a degree.
Snowstorms are frequent in the winter, with a vast accumulation of snow within a short period. Northern Indiana is the snowiest region due to the presence of lake effect snow in the Lake Michigan area. However, prolonged spells are rare in the state.

Spring in Indiana is marked by the transition from cold to warmth, making it a season of weather variability. During this period, Indiana witnesses an increase in tornadoes and thunderstorms. The temperatures in this season gradually rise, signaling the end of cold winter days. With the snow melting away, landscapes regain their vibrancy, making it a picturesque time to explore the state. However, visitors should be cautious of the occasional stormy weather and be prepared for sudden changes.

Indiana's summer is characterized by hot, humid, and wet conditions. Temperatures in July, the hottest month, often surpass 100°F (37.8°C). The high levels of humidity can make the weather feel more oppressive. The state sees the highest amount of rainfall during this season, providing a respite from the heat occasionally. While summer can be intense, it also offers plenty of sunny days and opportunities for outdoor activities.

Autumn in Indiana is primarily marked by sunny skies, low humidity, and mild temperatures. The state transitions from the hot summer to cooler temperatures, ranging between 65°F (18.3°C) and 85°F (29.4°C) during the day. As nights turn cooler, temperatures can vary from 40°F (4.4°C) to 60°F (15.6°C). The state is adorned with a palette of fall colors, making it a visual treat for visitors.

Winter in Indiana is typified by its cold and bitter conditions. Night temperatures can drop below 15°F (-9.4°C), especially in the northern parts. The influence of polar air masses from the north and warm air from the tropics results in frequent shifts in weather patterns. Snow is a common feature, especially in regions near Lake Michigan, with accumulation differing across the state. While the Great Lakes region remains the cloudiest, overall winter days tend to have limited sunshine.

January stands out as the coldest month in Indiana's calendar year. As the state is still in the grip of winter, it witnesses severe cold temperatures throughout its regions. Northern parts of the state, especially areas close to Lake Michigan, experience the brunt of the cold with nighttime temperatures often plummeting below 15°F (-9.4°C). Weather in January »

February in Indiana sees the continuation of the winter season, but with some subtle transitions as it bridges the gap between the intense cold of January and the approaching warmth of spring. The state, still under the influence of winter's cold grip, experiences cold temperatures, although generally milder than January. Weather in February »

As winter loosens its grip, March in Indiana acts as the doorway to spring, bringing with it a mixture of lingering cold and the first signs of warmer temperatures. The state starts to witness a more evident transition from winter to spring throughout the month, with temperatures steadily on the rise. Weather in March »

April in Indiana solidly anchors itself in the spring season, showcasing a more consistent rise in temperatures and a landscape transforming under the influence of increasing warmth. The bitter cold that occasionally marked the earlier months is now mostly a memory, with the state experiencing milder temperatures. Weather in April »

Indiana in May is a testament to the full bloom of spring, with temperatures on a consistent incline, heralding the imminent arrival of summer. The entire state, from the northern regions near Lake Michigan to the southernmost parts, experiences warming temperatures, typically ranging from 50°F (10°C) to 75°F (23.9°C). Weather in May »

With the transition from spring to summer, June in Indiana offers a delightful combination of long, sunlit days and temperatures that evoke the essence of the season. The state, as a whole, starts to experience the warmth of summer, with temperatures typically ranging from 60°F (15.6°C) to 85°F (29.4°C). Weather in June »

July stands as the pinnacle of summer in Indiana, boasting the warmest temperatures of the year. Across the state, from the northern areas bordering Lake Michigan to the southern extremities, temperatures comfortably settle between 65°F (18.3°C) and 90°F (32.2°C). Weather in July »

As August unfolds, Indiana experiences the concluding phases of summer, subtly hinting at the upcoming transition to autumn. Throughout the state, temperatures generally vary between 63°F (17.2°C) and 87°F (30.6°C). While the month maintains the warmth characteristic of summer, a gradual decline in temperature is noticeable, especially as it edges towards its end. Weather in August »

Indiana in September is a kaleidoscope of colors and a harbinger of the imminent fall season. The month witnesses a notable shift in temperatures, generally ranging from 55°F (12.8°C) to 78°F (25.6°C). The northern regions, influenced by their proximity to Lake Michigan, start to cool more rapidly than the southern parts, where summer warmth lingers a little longer. Rainfall in September slightly decreases compared to the preceding months, and the nature of the precipitation begins to change. Weather in September »

Indiana in October is a celebration of autumn, with nature adorning itself in vibrant hues of red, orange, and gold. The temperature sees a more pronounced decline this month, generally oscillating between 43°F (6.1°C) and 68°F (20°C). Weather in October »

As November unfolds in Indiana, there's an unmistakable chill in the air, signaling the approach of winter. Temperatures drop considerably during this month, typically ranging from 32°F (0°C) to 53°F (11.7°C). The northern regions of the state, already cooler due to Lake Michigan’s influence, begin to experience the first hints of winter frost, especially during the early mornings and late evenings. Rainfall in November lessens from the previous months, but the form of precipitation begins to diversify. Weather in November »

December in Indiana marks the firm commencement of the winter season. The mercury levels exhibit a notable drop, with temperatures typically fluctuating between 23°F (-5°C) and 40°F (4.4°C). Northern Indiana, always more susceptible to the bracing cold due to Lake Michigan, frequently records temperatures plummeting below freezing, especially during nighttime. With the decrease in temperature, the nature of precipitation undergoes a marked shift. Weather in December »