Indianapolis weather by month

The best time to visit Indianapolis is May, September and October — 89/100 in September, 27°C and 5 rainy days. The best season is autumn, September to November (78/100 on average).

The worst month is January at 41/100 — freezing, a little rain, clean air. See January →

Updated September 2026 · climate normals from ERA5 reanalysis

Planning the wider trip? Best time to visit United States →

Indianapolis🇺🇸 United States · Great Lakes & Midwest · City89
  1. 41Jan
  2. 54Feb
  3. 63Mar
  4. 74Apr
  5. 88May
  6. 79Jun
  7. 69Jul
  8. 78Aug
  9. 89Sep
  10. 82Oct
  11. 64Nov
  12. 49Dec

Best season: September to November (78/100 on average) · worst January (41/100)

Days
27°C
Nights
16°C
Wet days
5
Sun
9.9 h
Humidity
68%
Daylight
12 h
Indianapolis, United States
Photo: Steven Van Elk · Pexels

Indianapolis, month by month

Comfort score out of 100 for the kind of trip Indianapolis is best for, the average high, rainy days and hours of sun a day from the climate normals, and how busy it tends to be.

MonthScoreTierHighRainSunCrowdsOn
Jan41F2°C8 d5 hPeak1
Feb54D7°C8 d7 hQuiet—
Mar63C12°C10 d7 hPeak1
Apr74B18°C10 d9 hShoulder1
May88A23°C12 d10 hPeak3
Jun79B29°C9 d12 hPeak2
Jul69C30°C11 d12 hPeak3
Aug78B29°C8 d11 hPeak3
Sep89A27°C5 d10 hBusy1
Oct82A20°C8 d8 hBusy1
Nov64C11°C7 d6 hPeak3
Dec49F5°C8 d5 hPeak2

What's on in Indianapolis through the year

Festivals, natural spectacles, holidays and the seasons to watch out for — curated and sourced. The month pages carry the detail.

March
  • St. Patrick's Day Parade13–14 MarFestival
April
  • Spring storm season1 Apr – 30 Jun (usually)Hazard
May
  • 500 Festival Mini-Marathon1–10 May (usually)Festival
  • Indianapolis 50024 MayFestival
June
  • Indy Pride13–14 JunFestival
July
  • Brickyard 40015 Jul – 5 Aug (usually)Festival
  • Gen Con30 Jul – 2 AugFestival
  • Independence Day3–5 JulHoliday
August
  • Indiana State Fair7–23 AugFestival
September
  • Indy Jazz Fest22–26 SepFestival
October
  • Fall colour10 Oct – 5 Nov (usually)Nature
November
  • Circle of Lights24 Nov – 12 Jan (usually)Festival
  • Thanksgiving25–29 NovHoliday

Everything on in Indianapolis through the year →

Crowds in Indianapolis in September

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusySummer break in United States(estimated)

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Traveller notes on Indianapolis

What people who have been say about the place — the year-round notes first, then month by month.

Indianapolis forum threads describe January as genuinely cold, with posters citing an average temperature around freezing or slightly below, though generally manageable for walking around downtown rather than brutally harsh. One poster specifically reported a visit with temperatures around 10F, wind and an active snowstorm, illustrating the harsher end of what's possible. Posters were consistent that downtown is genuinely walkable from most hotels near the airport corridor, with a cab as a reliable backup if the weather doesn't cooperate on a given day. The standard advice for anyone not used to winter driving conditions was to lean on walking and cabs rather than renting a car for a short downtown visit.
MonumentCircleRegular · January · 1 month ago · Read more on Tripadvisor ↗
Indianapolis forum regulars describe late March with year-by-year examples rather than one forecast, because the swings are genuinely that wide: one year ran “45 to 65 degrees,” another hit “the 70s one week but 30s and 40s the following week,” a third stayed in a “58 to 74” band. The consistent advice across every thread: layers, and don't commit hard to an outdoor-only itinerary. The city's indoor fallback list is long enough to make that easy — the Eiteljorg Museum, the Indiana State Museum, the zoo (weather permitting), Newfields' art and gardens, plus a genuinely walkable downtown (the Cultural Trail, the canal, White River State Park) for whichever days turn out mild. Our record: 12°C days, 1.9°C nights, 12.4 rain days and 131.3mm of rain — cool and genuinely wet, sitting toward the cooler end of the range forums describe for the month.
Tripadvisor community · March · 1 month ago · Read more on Tripadvisor ↗
May in Indianapolis is the month of the race - practice, qualifying, the 500 Festival Parade and then the 500 itself on Memorial Day weekend - and every piece of advice regulars give first-timers is about the weather being unpredictable: sometimes very hot, sometimes bitter cold, and you prepare for both because the grandstands have no shade and no shelter. Our row's 23.4C over 13C is the average that spread sits either side of. The other figure to plan around is water: 130.5mm across 12 precipitation days makes May one of the wetter months of the Indianapolis year. The rest of their advice is logistical - arrive very early, the traffic near the track is dreadful, and only a small cooler comes into the seating area. The record: humidity 71 percent, 10 hours of sun, an 18.2 kph wind and AQI 48.
VeryHotOrBitterColdNoMiddle · May · 1 month ago · Read more on Tripadvisor ↗
Indianapolis's forum calls early September classically pleasant Midwest weather — warm but not hot by day, cool but not cold by night — while being honest that a 90°F day or a genuinely chilly one can both still happen. Regulars' standard advice: pack for both, shorts and a light shirt alongside pants and a jacket.
Tripadvisor community · September · 1 month ago · Read more on Tripadvisor ↗
October is the month locals pick when they have had enough of heat and humidity, and they explain the colour rather than dating it: the first good cold snap starts the turn, regular rain makes it vivid, and the display usually begins in the second week and runs a fortnight to three weeks, so late October is often the best of it. On temperature they offer a correction worth having - fifty degrees feels cold only in shade or wind, and warmer than you expect in still sun. Our row gives 19.6C days over 8.8C nights that feel like 6C, with dew on everything by morning. The record: 79.8mm across 7.7 days, 7.8 hours of sun and AQI 33.
TheFirstColdSnapStartsIt · October · 1 month ago · Read more on Tripadvisor ↗

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