Greencastle, Indiana climate: Normal weather by month, frost dates and records
Greencastle's normal year runs from 17°F January nights to 83°F July afternoons, with 46.1 inches of precipitation and 22 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.3°C, January lows of −8°C, July highs of 28°C, 1,172 mm of precipitation a year.
- NOAA stationGreencastle (1 mi W)
- Station IDUSC00123513
- Location39.64°N 86.88°W
- Elevation735 ft (224 m)
- Population9,907
On October 23, the normal high in Greencastle is 62°F and the normal low 38°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Greencastle.
- Jan 34° 17°
- Feb 39° 20°
- Mar 50° 29°
- Apr 62° 39°
- May 72° 49°
- Jun 80° 58°
- Jul 83° 61°
- Aug 82° 59°
- Sep 77° 52°
- Oct 65° 41°
- Nov 51° 30°
- Dec 39° 22°
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 Greencastle 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 (5.36 in), the least in February (2.63 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 17°F | 25.6°F | 3.18 | 9.3 | 11 | <1 | 27 | 9 h 40 min |
| February | 39°F | 20°F | 29.5°F | 2.63 | 4.3 | 9 | <1 | 24 | 10 h 40 min |
| March | 50°F | 29°F | 39.5°F | 3.50 | 2.2 | 11 | <1 | 20 | 11 h 50 min |
| April | 62°F | 39°F | 50.4°F | 4.65 | 0.1 | 12 | <1 | 6 | 13 h 10 min |
| May | 72°F | 49°F | 60.6°F | 4.91 | 0.0 | 13 | <1 | 1 | 14 h 20 min |
| June | 80°F | 58°F | 69.3°F | 5.36 | 0.0 | 11 | 3 | <1 | 15 h |
| July | 83°F | 61°F | 72.2°F | 4.72 | 0.0 | 10 | 6 | <1 | 14 h 40 min |
| August | 82°F | 59°F | 70.8°F | 3.36 | 0.0 | 9 | 4 | <1 | 13 h 50 min |
| September | 77°F | 52°F | 64.4°F | 3.67 | 0.0 | 8 | 1 | <1 | 12 h 30 min |
| October | 65°F | 41°F | 52.8°F | 3.59 | 0.1 | 8 | <1 | 5 | 11 h 10 min |
| November | 51°F | 30°F | 40.6°F | 3.61 | 0.9 | 10 | <1 | 16 | 10 h |
| December | 39°F | 22°F | 30.8°F | 2.96 | 5.2 | 12 | <1 | 25 | 9 h 20 min |
| Year (annual) | 61°F | 40°F | 50.5°F | 46.14 | 22.1 | 122 | 15 | 124 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −8°C | −3.6°C | 81 mm | 24 cm |
| February | 4°C | −7°C | −1.4°C | 67 mm | 11 cm |
| March | 10°C | −2°C | 4.2°C | 89 mm | 6 cm |
| April | 17°C | 4°C | 10.2°C | 118 mm | 0 cm |
| May | 22°C | 10°C | 15.9°C | 125 mm | 0 cm |
| June | 27°C | 15°C | 20.7°C | 136 mm | 0 cm |
| July | 28°C | 16°C | 22.3°C | 120 mm | 0 cm |
| August | 28°C | 15°C | 21.6°C | 85 mm | 0 cm |
| September | 25°C | 11°C | 18.0°C | 93 mm | 0 cm |
| October | 18°C | 5°C | 11.6°C | 91 mm | 0 cm |
| November | 11°C | −1°C | 4.8°C | 92 mm | 2 cm |
| December | 4°C | −5°C | −0.7°C | 75 mm | 13 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00123513; 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 Greencastle?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. 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 USC00123513.
When is the last frost in Greencastle?
In Greencastle, the last spring frost (32°F) comes after April 27 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 15 in half of years and before October 1 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 15; 9 in 10 after April 13
- First autumn frost, half of years before
- October 151 year in 10 before October 1; 9 in 10 before October 26
NOAA puts the median frost-free season at 169 days, and the season without a hard freeze (28°F) at 191 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Greencastle in zone 6a in ZIP code 46135, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Greencastle's NOAA station is in zone 6a: the coldest night of a typical year reaches −7°F (21 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 USC00123513; 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 Greencastle?
In a normal year in Greencastle, 15 days a year reach 90°F, 124 nights fall to 32°F or colder and 122 days bring measurable precipitation.
- Days at 90°F or more
- 15a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 124a normal year
- Days that stay below freezing
- 33high of 32°F or less
- Days with 0.01 inch of precipitation
- 122a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1895) is 108°F, on July 8, 1936; the lowest is −23°F, on January 21, 1985.
The wettest calendar year on that record is 2008, with 59.89 in; the snowiest season is 1977–78, with 62.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00123513; records: ACIS (NOAA Regional Climate Centers), station USC00123513. Records use complete months only; a month missing more than three days is left out.
How sunny is Greencastle?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Greencastle, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (59%).
| 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 Greencastle need?
A normal year in Greencastle brings 5,973 heating degree days, 11% more than the median U.S. place (5,373), and 733 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 3,059 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,220 | 0 |
| February | 995 | 0 |
| March | 793 | 1 |
| April | 446 | 6 |
| May | 188 | 50 |
| June | 34 | 162 |
| July | 7 | 230 |
| August | 12 | 192 |
| September | 98 | 81 |
| October | 389 | 11 |
| November | 732 | 0 |
| December | 1,060 | 0 |
| Year (annual) | 5,973 | 733 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00123513. 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.
How does Greencastle's climate compare?
Greencastle is warmer than 30 of the other 98 places with their own NOAA record in Indiana, and wetter than 62. Across the 7,247 U.S. stations with normals, its annual mean of 50.5°F is warmer than 43%.
In the Köppen classification computed from these normals, Greencastle 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 Greencastle share this climate record?
13 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.
- Heritage Lake, IN2,913 people · 11 mi NE
- Cloverdale, IN2,172 people · 9 mi SE
- Putnamville, IN2,126 people · 5 mi S
- Bainbridge, IN710 people · 9 mi NE
- Harmony, IN673 people · 13 mi SW
- Coatesville, IN573 people · 11 mi E
- Fillmore, IN552 people · 7 mi E
- Van Bibber Lake, IN483 people · 7 mi NW
- Amo, IN426 people · 14 mi E
- Stilesville, IN276 people · 13 mi E
- Carbon, IN258 people · 13 mi W
- Groveland, IN217 people · 12 mi NE
- Poland, IN92 people · 14 mi S
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 Greencastle's climate
What is the coldest month in Greencastle?
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 Greencastle?
Yes: 22 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (9.3 inches).
What is the rainiest month in Greencastle?
June, with 5.36 in of precipitation in a normal year; the driest is February with 2.63 in.
What plant hardiness zone is Greencastle in?
The USDA's 2023 map puts Greencastle in zone 6a in ZIP code 46135, the nearest ZIP area. By the same method at Greencastle's NOAA station, the coldest night of a typical year reaches −7°F (21 years, 1991-2020): zone 6a.
How late can frost come in Greencastle?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 15. Waiting until May 15 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Rockville, IN21 miles from this station, 52.0°F a year
- Jamestown, IN24 miles from this station, 51.2°F a year
- Crawfordsville, IN25 miles from this station, 50.4°F a year
- Spencer, IN25 miles from this station, 52.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made