New Castle, Indiana climate: Normal weather by month, frost dates and records
New Castle's normal year runs from 17°F January nights to 83°F July afternoons, with 44.4 inches of precipitation and 25 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.2°C, January lows of −8°C, July highs of 28°C, 1,126 mm of precipitation a year.
- NOAA stationNew Castle (3 mi SW)
- Station IDUSC00126164
- Location39.89°N 85.40°W
- Elevation991 ft (302 m)
- From the center2 miles
- Population17,382
On October 23, the normal high in New Castle is 62°F and the normal low 39°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for New Castle.
- Jan 34° 17°
- Feb 38° 19°
- Mar 49° 28°
- Apr 62° 38°
- May 72° 50°
- Jun 80° 59°
- Jul 83° 61°
- Aug 82° 59°
- Sep 77° 52°
- Oct 65° 41°
- Nov 51° 31°
- Dec 39° 23°
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 New Castle each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 17°F. The most precipitation falls in June (5.34 in), the least in February (2.46 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 17°F | 25.6°F | 3.01 | 7.9 | 13 | <1 | 28 | 9 h 40 min |
| February | 38°F | 19°F | 28.7°F | 2.46 | 6.4 | 11 | <1 | 25 | 10 h 40 min |
| March | 49°F | 28°F | 38.4°F | 3.40 | 3.4 | 12 | <1 | 21 | 11 h 50 min |
| April | 62°F | 38°F | 50.1°F | 4.42 | 0.3 | 13 | <1 | 9 | 13 h 10 min |
| May | 72°F | 50°F | 60.9°F | 4.85 | 0.0 | 13 | <1 | 1 | 14 h 20 min |
| June | 80°F | 59°F | 69.4°F | 5.34 | 0.0 | 12 | 1 | <1 | 15 h |
| July | 83°F | 61°F | 72.1°F | 4.70 | 0.0 | 11 | 3 | <1 | 14 h 50 min |
| August | 82°F | 59°F | 70.5°F | 3.38 | 0.0 | 8 | 2 | <1 | 13 h 50 min |
| September | 77°F | 52°F | 64.6°F | 3.07 | 0.0 | 8 | 2 | <1 | 12 h 30 min |
| October | 65°F | 41°F | 53.1°F | 3.23 | 0.0 | 9 | <1 | 6 | 11 h 10 min |
| November | 51°F | 31°F | 40.8°F | 3.45 | 0.9 | 10 | <1 | 18 | 10 h |
| December | 39°F | 23°F | 30.9°F | 3.04 | 5.9 | 12 | <1 | 25 | 9 h 20 min |
| Year (annual) | 61°F | 40°F | 50.4°F | 44.35 | 24.8 | 131 | 9 | 132 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −8°C | −3.6°C | 76 mm | 20 cm |
| February | 3°C | −7°C | −1.8°C | 62 mm | 16 cm |
| March | 9°C | −2°C | 3.6°C | 86 mm | 9 cm |
| April | 17°C | 4°C | 10.1°C | 112 mm | 1 cm |
| May | 22°C | 10°C | 16.1°C | 123 mm | 0 cm |
| June | 27°C | 15°C | 20.8°C | 136 mm | 0 cm |
| July | 28°C | 16°C | 22.3°C | 119 mm | 0 cm |
| August | 28°C | 15°C | 21.4°C | 86 mm | 0 cm |
| September | 25°C | 11°C | 18.1°C | 78 mm | 0 cm |
| October | 18°C | 5°C | 11.7°C | 82 mm | 0 cm |
| November | 10°C | −1°C | 4.9°C | 88 mm | 2 cm |
| December | 4°C | −5°C | −0.6°C | 77 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00126164; 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 New Castle?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. Of those, August 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 USC00126164.
When is the last frost in New Castle?
In New Castle, the last spring frost (32°F) comes after April 27 in half of years and after May 12 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 4 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 271 year in 10 after May 12; 9 in 10 after April 11
- First autumn frost, half of years before
- October 171 year in 10 before October 4; 9 in 10 before October 28
NOAA puts the median frost-free season at 173 days, and the season without a hard freeze (28°F) at 194 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 27 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts New Castle in zone 6a in ZIP code 47362, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, New Castle's NOAA station is in zone 6a: the coldest night of a typical year reaches −9°F (27 complete years).
Frost dates for every NOAA station in Indiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00126164; 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.
How hot and how cold does it get in New Castle?
In a normal year in New Castle, 9 days a year reach 90°F, 132 nights fall to 32°F or colder and 131 days bring measurable precipitation.
- Days at 90°F or more
- 9a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 132a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 131a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1949) is 107°F, on June 29, 2012; the lowest is −26°F, on January 20, 1994.
The wettest calendar year on that record is 2011, with 63.46 in; the snowiest season is 2013–14, with 51.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00126164; records: ACIS (NOAA Regional Climate Centers), station USC00126164. Records use complete months only; a month missing more than three days is left out.
How sunny is New Castle?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around New Castle, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 60% | 1.8 |
| February | 62% | 2.6 |
| March | 66% | 3.6 |
| April | 71% | 4.9 |
| May | 72% | 5.5 |
| June | 79% | 6.2 |
| July | 80% | 6.1 |
| August | 81% | 5.6 |
| September | 79% | 4.5 |
| October | 73% | 3.2 |
| November | 69% | 2.2 |
| December | 58% | 1.5 |
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 New Castle need?
A normal year in New Castle brings 6,018 heating degree days, 12% more than the median U.S. place (5,373), and 737 cooling degree days, 19% fewer 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 3,058 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,221 | 0 |
| February | 1,016 | 0 |
| March | 826 | 1 |
| April | 454 | 7 |
| May | 184 | 58 |
| June | 32 | 164 |
| July | 7 | 225 |
| August | 13 | 181 |
| September | 99 | 87 |
| October | 382 | 13 |
| November | 726 | 0 |
| December | 1,059 | 0 |
| Year (annual) | 6,018 | 737 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00126164. 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 New Castle been warmer than normal lately?
2025 averaged 51.0°F, 0.6°F above the 1991-2020 normal of 50.4°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 51.3°F | +0.9°F | 44.91 | 28.6 |
| 2022 | 50.0°F | −0.4°F | 38.50 | 19.7 |
| 2023 | 52.5°F | +2.1°F | 34.74 | 6.8 |
| 2024 | 53.5°F | +3.1°F | 40.16 | 20.1 |
| 2025 | 51.0°F | +0.6°F | 36.52 | 31.3 |
Over 62 complete years from 1950 to 2025, the station's annual mean temperature rose at a fitted 3.6°F per century (+0.20°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00126164; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does New Castle's climate compare?
New Castle is warmer than 26 of the other 98 places with their own NOAA record in Indiana, and wetter than 53. Across the 7,247 U.S. stations with normals, its annual mean of 50.4°F is warmer than 42%.
In the Köppen classification computed from these normals, New Castle 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 New Castle share this climate record?
12 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.
- Knightstown, IN2,158 people · 10 mi SW
- Spiceland, IN963 people · 4 mi SW
- Shirley, IN840 people · 10 mi W
- Westwood, IN555 people · 2 mi NW
- Kennard, IN451 people · 7 mi W
- Mount Summit, IN349 people · 8 mi N
- Lewisville, IN340 people · 6 mi S
- Sulphur Springs, IN335 people · 7 mi N
- Dunreith, IN170 people · 7 mi S
- Cadiz, IN161 people · 6 mi NW
- Springport, IN134 people · 11 mi N
- Greensboro, IN125 people · 4 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.
Questions about New Castle's climate
What is the coldest month in New Castle?
January, with a normal high of 34°F and a normal low of 17°F. The warmest is July (83°F by day, 61°F at night).
Does it snow in New Castle?
Yes: 25 inches in a normal year, falling on 17 days with 0.1 inch or more, the most in January (7.9 inches).
What is the rainiest month in New Castle?
June, with 5.34 in of precipitation in a normal year; the driest is February with 2.46 in.
What plant hardiness zone is New Castle in?
The USDA's 2023 map puts New Castle in zone 6a in ZIP code 47362, the nearest ZIP area. By the same method at New Castle's NOAA station, the coldest night of a typical year reaches −9°F (27 years, 1991-2020): zone 6a.
How late can frost come in New Castle?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 12. Waiting until May 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Cambridge City, IN11 miles from this station, 49.8°F a year
- Rushville, IN21 miles from this station, 51.7°F a year
- Greenfield, IN21 miles from this station, 51.9°F a year
- Anderson, IN23 miles from this station, 52.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made