Indianapolis, Indiana climate: Normal weather by month, frost dates and records
Indianapolis's normal year runs from 21°F January nights to 85°F July afternoons, with 43.6 inches of precipitation and 26 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.0°C, January lows of −6°C, July highs of 30°C, 1,108 mm of precipitation a year.
- NOAA stationIndianapolis International Airport
- Station IDUSW00093819
- Location39.71°N 86.28°W
- Elevation790 ft (241 m)
- From the center9 miles
- Population891,484
On October 22, the normal high in Indianapolis is 63°F and the normal low 43°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Indianapolis.
- Jan 36° 21°
- Feb 41° 24°
- Mar 52° 33°
- Apr 64° 43°
- May 73° 54°
- Jun 82° 63°
- Jul 85° 66°
- Aug 84° 65°
- Sep 78° 57°
- Oct 66° 46°
- Nov 52° 35°
- Dec 40° 26°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Indianapolis each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 21°F. The most precipitation falls in June (4.95 in), the least in February (2.43 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 21°F | 28.5°F | 3.12 | 8.8 | 12 | <1 | 26 | 9 h 40 min |
| February | 41°F | 24°F | 32.5°F | 2.43 | 6.0 | 10 | <1 | 22 | 10 h 40 min |
| March | 52°F | 33°F | 42.4°F | 3.69 | 3.2 | 12 | <1 | 16 | 11 h 50 min |
| April | 64°F | 43°F | 53.6°F | 4.34 | 0.2 | 12 | <1 | 4 | 13 h 10 min |
| May | 73°F | 54°F | 63.6°F | 4.75 | 0.0 | 13 | <1 | <1 | 14 h 20 min |
| June | 82°F | 63°F | 72.5°F | 4.95 | 0.0 | 12 | 3 | <1 | 15 h |
| July | 85°F | 66°F | 75.8°F | 4.42 | 0.0 | 10 | 7 | <1 | 14 h 40 min |
| August | 84°F | 65°F | 74.7°F | 3.20 | 0.0 | 8 | 6 | <1 | 13 h 50 min |
| September | 78°F | 57°F | 67.8°F | 3.14 | 0.0 | 8 | 3 | <1 | 12 h 30 min |
| October | 66°F | 46°F | 55.5°F | 3.22 | 0.1 | 9 | <1 | 2 | 11 h 10 min |
| November | 52°F | 35°F | 43.3°F | 3.45 | 0.8 | 10 | <1 | 13 | 10 h |
| December | 40°F | 26°F | 33.3°F | 2.92 | 6.4 | 12 | <1 | 23 | 9 h 20 min |
| Year (annual) | 63°F | 45°F | 53.6°F | 43.63 | 25.5 | 128 | 20 | 106 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −6°C | −1.9°C | 79 mm | 22 cm |
| February | 5°C | −4°C | 0.3°C | 62 mm | 15 cm |
| March | 11°C | 1°C | 5.8°C | 94 mm | 8 cm |
| April | 18°C | 6°C | 12.0°C | 110 mm | 1 cm |
| May | 23°C | 12°C | 17.6°C | 121 mm | 0 cm |
| June | 28°C | 17°C | 22.5°C | 126 mm | 0 cm |
| July | 30°C | 19°C | 24.3°C | 112 mm | 0 cm |
| August | 29°C | 18°C | 23.7°C | 81 mm | 0 cm |
| September | 26°C | 14°C | 19.9°C | 80 mm | 0 cm |
| October | 19°C | 8°C | 13.1°C | 82 mm | 0 cm |
| November | 11°C | 2°C | 6.3°C | 88 mm | 2 cm |
| December | 5°C | −3°C | 0.7°C | 74 mm | 16 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093819; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Indianapolis?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. Of those, September has the fewest days with rain (8).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093819.
When is the last frost in Indianapolis?
In Indianapolis, the last spring frost (32°F) comes after April 15 in half of years and after May 2 in one year in ten; the first autumn frost comes before October 26 in half of years and before October 13 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 151 year in 10 after May 2; 9 in 10 after April 2
- First autumn frost, half of years before
- October 261 year in 10 before October 13; 9 in 10 before November 7
NOAA puts the median frost-free season at 193 days, and the season without a hard freeze (28°F) at 215 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Indianapolis in zones 6a to 6b across its 35 ZIP code areas (6a in 46239, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Indianapolis's NOAA station is in zone 6b: the coldest night of a typical year reaches −5°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Indiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00093819; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Indianapolis ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Indianapolis's 35 ZIP code areas run from zone 6a to 6b: 16 in 6a and 19 in 6b. Each ZIP's frost dates are in the frost tool.
| ZIP code | Zone | Land in Indianapolis |
|---|---|---|
| 46113 | 6a | 15.4 km² |
| 46201 | 6b | 14.5 km² |
| 46202 | 6b | 14.2 km² |
| 46203 | 6b | 33.3 km² |
| 46204 | 6b | 2.9 km² |
| 46205 | 6b | 16.2 km² |
| 46208 | 6b | 17.1 km² |
| 46214 | 6b | 19.3 km² |
| 46217 | 6b | 54.8 km² |
| 46218 | 6a | 24.7 km² |
| 46219 | 6a | 32.6 km² |
| 46220 | 6b | 30.2 km² |
| 46221 | 6b | 51.8 km² |
| 46222 | 6b | 24.9 km² |
| 46224 | 6b | 9.8 km² |
| 46225 | 6b | 10.3 km² |
| 46226 | 6a | 26.8 km² |
| 46227 | 6b | 41.0 km² |
| 46228 | 6b | 18.6 km² |
| 46229 | 6a | 24.5 km² |
| 46231 | 6b | 14.5 km² |
| 46234 | 6a | 14.3 km² |
| 46235 | 6a | 14.4 km² |
| 46236 | 6a | 5.3 km² |
| 46237 | 6a | 37.8 km² |
| 46239 | 6a | 72.6 km² |
| 46240 | 6b | 22.4 km² |
| 46241 | 6b | 61.9 km² |
| 46250 | 6a | 19.9 km² |
| 46254 | 6b | 32.6 km² |
| 46256 | 6a | 26.1 km² |
| 46259 | 6a | 39.9 km² |
| 46260 | 6a | 24.6 km² |
| 46268 | 6a | 32.1 km² |
| 46278 | 6a | 32.8 km² |
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Indianapolis?
In a normal year in Indianapolis, 20 days a year reach 90°F, 106 nights fall to 32°F or colder and 128 days bring measurable precipitation.
- Days at 90°F or more
- 20a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 106a normal year
- Days that stay below freezing
- 29high of 32°F or less
- Days with 0.01 inch of precipitation
- 128a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in Indianapolis's official record (kept by the National Weather Service since 1871) is 106°F, on July 22, 1901; the lowest is −27°F, on January 19, 1994.
The wettest calendar year on that record is 1876, with 57.65 in; the snowiest season is 1981–82, with 58.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00093819; records: ACIS (NOAA Regional Climate Centers), NWS threaded record INDthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Indianapolis, and how clear are its skies?
The summer (June-August) dew point averages 63°F. The muggiest month is July, with an average dew point of 64°F; the driest air comes in January (21°F). February is the windiest month (11.2 mph on average), and September has the most clear or nearly clear hours (48%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 21°F | 73% | 63% | 10.7 mph | 27% | 52% |
| February | 27°F | 69% | 56% | 11.2 mph | 26% | 51% |
| March | 36°F | 63% | 50% | 11.1 mph | 29% | 43% |
| April | 45°F | 64% | 51% | 10.4 mph | 31% | 39% |
| May | 57°F | 68% | 52% | 9.0 mph | 29% | 32% |
| June | 64°F | 69% | 53% | 8.0 mph | 36% | 24% |
| July | 64°F | 69% | 52% | 7.4 mph | 38% | 20% |
| August | 62°F | 69% | 51% | 7.5 mph | 43% | 19% |
| September | 51°F | 68% | 48% | 8.6 mph | 48% | 22% |
| October | 39°F | 69% | 54% | 9.8 mph | 34% | 40% |
| November | 30°F | 73% | 62% | 10.5 mph | 26% | 52% |
| December | 24°F | 77% | 68% | 10.5 mph | 25% | 57% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00093819. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Indianapolis?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Indianapolis, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (59%). Among the 459 U.S. places of 50,000 or more, that ranks tied 352nd (with 32 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.8 |
| February | 63% | 2.6 |
| March | 66% | 3.7 |
| April | 71% | 4.8 |
| May | 72% | 5.5 |
| June | 79% | 6.3 |
| July | 80% | 6.1 |
| August | 81% | 5.5 |
| September | 80% | 4.6 |
| October | 73% | 3.2 |
| November | 69% | 2.2 |
| December | 59% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Indianapolis need?
A normal year in Indianapolis brings 5,250 heating degree days, 2% fewer than the median U.S. place (5,373), and 1,139 cooling degree days, 26% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,715 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,131 | 0 |
| February | 910 | 0 |
| March | 702 | 3 |
| April | 355 | 13 |
| May | 131 | 86 |
| June | 14 | 237 |
| July | 1 | 336 |
| August | 2 | 301 |
| September | 58 | 142 |
| October | 314 | 21 |
| November | 650 | 1 |
| December | 983 | 0 |
| Year (annual) | 5,250 | 1,139 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093819. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Indianapolis been warmer than normal lately?
2025 averaged 54.7°F, 1.1°F above the 1991-2020 normal of 53.6°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 54.8°F | +1.2°F | 49.75 | 22.2 |
| 2022 | 53.9°F | +0.3°F | 34.88 | 14.9 |
| 2023 | 56.1°F | +2.5°F | 34.38 | 5.7 |
| 2024 | 56.9°F | +3.3°F | 43.53 | 12.3 |
| 2025 | 54.7°F | +1.1°F | 36.70 | 31.6 |
Over 143 complete years from 1872 to 2025, the station's annual mean temperature rose at a fitted 2.7°F per century (+0.15°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00093819; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Indianapolis's climate compare?
Indianapolis is warmer than 68 of the other 98 places with their own NOAA record in Indiana, and wetter than 49. Across the 7,247 U.S. stations with normals, its annual mean of 53.6°F is warmer than 55%.
In the Köppen classification computed from these normals, Indianapolis is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Indianapolis share this climate record?
11 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Plainfield, IN37,796 people · 5 mi W
- Brownsburg, IN33,430 people · 10 mi NW
- Avon, IN24,735 people · 7 mi NW
- Speedway, IN14,268 people · 6 mi N
- Danville, IN12,532 people · 12 mi W
- Mooresville, IN10,027 people · 9 mi SW
- Clermont, IN1,385 people · 8 mi N
- Waverly, IN1,006 people · 11 mi S
- Clayton, IN949 people · 13 mi W
- Belleville, IN536 people · 11 mi W
- Cartersburg, IN67 people · 10 mi W
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Indianapolis's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Indianapolis. This page uses Indianapolis International Airport; the others differ by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Indianapolis Eagle Creek Airport USW00053842 | 9 mi NW | 823 ft | 53.7°F | 21°F | 85°F | 40.7 | – | April 12 |
| Indianapolis Nwfo USC00124260 | 9 mi SW | 790 ft | 53.3°F | 19°F | 85°F | 45.8 | – | April 12 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Indianapolis's climate
What is the coldest month in Indianapolis?
January, with a normal high of 36°F and a normal low of 21°F. The warmest is July (85°F by day, 66°F at night).
Does it snow in Indianapolis?
Yes: 26 inches in a normal year, falling on 22 days with 0.1 inch or more, the most in January (8.8 inches).
What is the rainiest month in Indianapolis?
June, with 4.95 in of precipitation in a normal year; the driest is February with 2.43 in.
What plant hardiness zone is Indianapolis in?
The USDA's 2023 map puts Indianapolis in zones 6a to 6b across its 35 ZIP code areas (6a in 46239, the largest). By the same method at Indianapolis's NOAA station, the coldest night of a typical year reaches −5°F (30 years, 1991-2020): zone 6b.
How late can frost come in Indianapolis?
In half of years the last 32°F night comes after April 15; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indianapolis in OctoberThis month day by day, its records and recent years
- Indiana climateThe statewide normals and every place in the state
- Beech Grove, IN11 miles from this station, 51.8°F a year
- Castleton (2 mi S), IN17 miles from this station, 52.7°F a year
- Whitestown, IN21 miles from this station, 51.9°F a year
- Franklin, IN21 miles from this station, 51.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made