Climate and monthly weather forecast
Indianapolis, IN

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The magnificent Monument Circle in Indianapolis, Indiana with the surrounding cityscape
The magnificent Monument Circle in Indianapolis, Indiana with the surrounding cityscape

The climate of Indianapolis

Geographically situated within the mid-west portion of the United States, Indianapolis, Indiana, typifies the Humid Subtropical climate. Under the Köppen climate classification, it holds the designation of Cfa, with high levels of humidity and no dry season. A year-round analysis of weather patterns in Indianapolis indicates mild to occasionally high temperature variances with distinct seasonal changes.

The city experiences temperatures ranging from a low 21°F (-6.1°C) during winter months to a high of up to 82°F (27.8°C) during summer. Similarly, humidity levels fluctuate between 73% to 82%, portraying the persistently high moisture content typical of a subtropical climate. Rainfall in Indianapolis shows moderate variability throughout the year, with monthly averages fluctuating from 1.22" (31mm) to 2.68" (68mm).

The quantity of daylight, sun exposure, and UV index each align with seasonal expectations. Extended daylight hours from 14.4 to 15 hours mark the summer months. Concurrently, warmer months exhibit more sunshine hours and a higher UV index of 6. Winter, on the other hand, sees shorter daylight hours from 9.4 to 10.7 hours, fewer hours of sunshine, and a lower UV index of 2.

The best time to visit Indianapolis

Visitors may find the period between May and June to be the most favorable for planning a trip to Indianapolis. The city experiences moderately high temperatures from 61.5°F (16.4°C) to 71.8°F (22.1°C) during this period. Coupled with the longest daylight hours and a favorable UV index, these months offer excellent conditions for outdoor activities.

The worst time to visit Indianapolis

Travelers might want to avoid the coldest months of January and February, as Indianapolis experiences rather chilly conditions during this time. The average low temperatures sink to 21°F (-6.1°C) and go up to just 38.3°F (3.5°C) making it less inviting for outdoor excursions or activities.

Spring weather in Indianapolis

Spring ushers in Indianapolis gradually with temperatures ascending from a cool 50°F (10°C) in March to a warmer 71.8°F (22.1°C) in May. It's also the start of the rainy season, with rainfall reaching up to 2.68" (68mm) in the culminating month of May. The expanding daylight hours and increased sunshine hours certainly boost the allure of the spring season.

Summer weather in Indianapolis

Summer in the city usually runs from June through August, with temperatures rocketing between 80.2°F (26.8°C) to 82°F (27.8°C), making it the hot spot of the year. Rainfall inches down marginally from 2.48" (63mm) to 1.65" (42mm) during these months. The extended hours of daylight, consistent UV index, and highest sunshine exposure accentuate the heat of the season.

Autumn weather in Indianapolis

Autumn starts to settle in Indianapolis around September, as temperatures descend comfortably from 75.9°F (24.4°C) to a cooler 49.3°F (9.6°C) by November. While warm clothing might be needed, this season experiences relatively less rainfall ranging from 1.46" (37mm) to1.3" (33mm). Daylight hours and sunshine hours gradually shrink, reflecting the seasonal transition.

Winter weather in Indianapolis

As December ushers in winter, Indianapolis commences a phase of cold, with temperatures settling between 38.3°F (3.5°C) to a low of 21°F (-6.1°C) throughout the season. Light snowfall begins to mark the landscape with their presence, accumulating about 2.28" (58mm) in December. The shortened daylight hours and minimal sunshine mirror the frosty conditions characteristic of this season.

Weather in January

The start of the year in Indianapolis, Indiana brings with it a typical winter climate. Blankets of snow cover the city as temperatures struggle to surpass 33.4°F (0.8°C) and can dip as low as 21°F (-6.1°C). Expect frost-crusted mornings and frostbite-inducing nights. Weather in January »

Weather in February

Moving into February, Indianapolis experiences a slight climate shift as temperatures begin to slowly rise, reaching a peak of 38.3°F (3.5°C). The snowfall tapers off from January levels, but one can still expect to see the snow-capped cityscape. Weather in February »

Weather in March

March marks a significant change in weather for Indianapolis as the city finally begins to thaw. Temperatures rise to a comfortable maximum of around 50°F (10°C) making outdoor activities more appealing. The dusting of snow the city receives is a residual goodbye wave from the winter. Weather in March »

Weather in April

The arrival of April signals the arrival of spring in full bloom across Indianapolis. Temperatures, more agreeable now, swing between 61.5°F (16.4°C) to a minimum of 45.1°F (7.3°C). The snow has completely retreated leaving greenery in its wake. Weather in April »

Weather in May

May brings with it the true essence of spring in Indianapolis. The climate attains a pleasant balance as temperatures hover around 71.8°F (22.1°C). Longer days provide ample sunshine to the city, ensuring beautiful days for picnics and walks in the parks. Weather in May »

Weather in June

June in Indianapolis signals the onset of summer with a high average temperature reaching around 80.2°F (26.8°C). The weather becomes more inviting for use of the city's outdoor amenities. Increased daylight hours certainly add a charm to the city's numerous outdoor events. Weather in June »

Weather in July

July rightly earns the distinction of being the hottest month in Indianapolis with an average high temperature of 82°F (27.8°C). The summer sun shines brightly, dominating the city's weather pattern. Although the city is at its warmest, it's a great time for locals and tourists to enjoy water-sports and other outdoor activities. Weather in July »

Weather in August

In August, Indianapolis sees slightly lower temperatures than the previous month, with temperatures varying from 81.1°F (27.3°C) to 64°F (17.8°C). While the sun continues to rule the sky, there's no dearth of refreshing breezes. Weather in August »

Weather in September

September brings with it a welcoming transition from the heat of summer to the cool of autumn in Indianapolis. While temperatures remain high at about 75.9°F (24.4°C), there’s an evident decrease towards the end of the month. Weather in September »

Weather in October

October in Indianapolis carries the essence of autumn, an intermediate period between the warm summer and brisk winter. As temperatures moderate, falling to an average low of 47.3°F (8.5°C), the city is imbued with a refreshing chill. Weather in October »

Weather in November

November witnesses a significant drop in temperature, as Indianapolis braces for the upcoming winter. With the mercury dropping to an average low of 36.1°F (2.3°C), the city dons its winter attire. The chill air brings with it a sense of anticipation for the impending holiday season. Weather in November »

Weather in December

December in Indianapolis can be described as a perfect winter wonderland with the landscape turning shades of white thanks to an average snowfall of 2.28" (58mm). The temperature hovers around a chilly 38.3°F (3.5°C), while the holiday lights twinkle across the cityscape. Weather in December »

Frequently asked questions

What part of the year is the coldest?

During the coldest month in Indianapolis, January, temperatures average a high of 33.4°F (0.8°C) and a low of 21°F (-6.1°C).

How much does it rain in Indianapolis?

Throughout the year, there are 146.4 rainfall days, and 21.14" (537mm) of precipitation is accumulated.

When does it snow?

January through April, November and December are months with snowfall.

How many days does it snow?

Throughout the year, there are 28.1 snowfall days, and 7.87" (200mm) of snow is accumulated.

What is the month with the least sunshine?

The month with the least sunshine is January, with an average of 4.1h of sunshine.

What is the month with the lowest UV index?

The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2.

What is the driest month?

February is the month with the least rainfall. Rain falls for 6.8 days and accumulates 1.22" (31mm) of precipitation.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

What is the wettest month?

May is the month with the most rainfall. Rain falls for 17.6 days and accumulates 2.68" (68mm) of precipitation.

When it does not snow?

In Indianapolis, snow does not fall in May through October.

When is the highest UV index?

The months with the highest UV index are May through August, with an average maximum UV index of 6.

When are the longest days?

The month with the longest days is June, with an average of 14h and 54min of daylight.

What month is the hottest?

In Indianapolis, July is identified by the average highest temperatures, reaching a peak of 82°F (27.8°C) and a low of 66.2°F (19°C).

What month has the most sunshine?

July has the most sunshine of the year, with an average of 10.3h of sunshine.

What is the least humid month?

The least humid month is October, with an average relative humidity of 73%.

What is the most humid month?

December is the most humid month, with an average relative humidity of 82%.

When does it snow the most?

December is the month with the most snowfall. Snow falls for 6.2 days and accumulates 2.28" (58mm) of snow.

What is the month with the shortest days in Indianapolis?

The month with the shortest days is December, with an average of 9h and 24min of daylight.

Average temperature
Indianapolis, IN

Average temperature - Indianapolis, IN

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.4°F).

The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (21°F).

Average pressure
Indianapolis, IN

Average pressure - Indianapolis, IN

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed
Indianapolis, IN

Average wind speed - Indianapolis, IN

The windiest months (with the highest average wind speed) are January and February (9.8mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

Average humidity
Indianapolis, IN

Average humidity - Indianapolis, IN

The month with the highest relative humidity is December (82%).
The month with the lowest relative humidity is October (73%).

Average rainfall
Indianapolis, IN

Average rainfall - Indianapolis, IN

The wettest month (with the highest rainfall) is May (2.68").
The driest month (with the least rainfall) is February (1.22").

Average rainfall days
Indianapolis, IN

Average rainfall days - Indianapolis, IN

The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is February (6.8 days).

Average snowfall
Indianapolis, IN

Average snowfall - Indianapolis, IN

The month with the highest snowfall is December (2.28").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days
Indianapolis, IN

Average snowfall days - Indianapolis, IN

The month with the highest number of snowfall days is January (7.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Indianapolis, IN

Average daylight / Average sunshine - Indianapolis, IN

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days
Indianapolis, IN

Average sunshine days - Indianapolis, IN

The month with the most sunshine days is October (18.6 days).
The month with the least sunshine days is May (11.1 days).

Average UV index
Indianapolis, IN

Average UV index - Indianapolis, IN

The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).

Average visibility
Indianapolis, IN

Average visibility - Indianapolis, IN

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Indianapolis, Indiana, USA

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