Rockville, Indiana climate: Normal weather by month, frost dates and records
Rockville's normal year runs from 17°F January nights to 86°F July afternoons, with 47.4 inches of precipitation and 13 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.1°C, January lows of −8°C, July highs of 30°C, 1,205 mm of precipitation a year.
- NOAA stationRockville
- Station IDUSC00127522
- Location39.76°N 87.23°W
- Elevation689 ft (210 m)
- Population2,589
On October 23, the normal high in Rockville is 64°F and the normal low 39°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rockville.
- Jan 36° 17°
- Feb 41° 21°
- Mar 52° 29°
- Apr 66° 40°
- May 76° 50°
- Jun 84° 58°
- Jul 86° 62°
- Aug 85° 60°
- Sep 79° 53°
- Oct 67° 42°
- Nov 52° 31°
- Dec 40° 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 Rockville each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 17°F. The most precipitation falls in June (5.45 in), the least in February (2.60 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 17°F | 26.5°F | 3.38 | 5.1 | 8 | <1 | 25 | 9 h 40 min |
| February | 41°F | 21°F | 30.9°F | 2.60 | 2.8 | 7 | <1 | 22 | 10 h 40 min |
| March | 52°F | 29°F | 40.8°F | 3.32 | 1.1 | 8 | <1 | 17 | 11 h 50 min |
| April | 66°F | 40°F | 52.8°F | 4.96 | 0.1 | 10 | <1 | 5 | 13 h 10 min |
| May | 76°F | 50°F | 62.7°F | 5.02 | 0.0 | 11 | 1 | <1 | 14 h 20 min |
| June | 84°F | 58°F | 71.0°F | 5.45 | 0.0 | 10 | 7 | <1 | 15 h |
| July | 86°F | 62°F | 73.9°F | 4.70 | 0.0 | 9 | 10 | <1 | 14 h 40 min |
| August | 85°F | 60°F | 72.3°F | 3.84 | 0.0 | 8 | 7 | <1 | 13 h 50 min |
| September | 79°F | 53°F | 65.9°F | 3.14 | 0.0 | 6 | 3 | <1 | 12 h 30 min |
| October | 67°F | 42°F | 54.2°F | 3.87 | 0.0 | 8 | <1 | 4 | 11 h 10 min |
| November | 52°F | 31°F | 41.7°F | 3.90 | 0.3 | 8 | <1 | 15 | 10 h |
| December | 40°F | 22°F | 31.0°F | 3.25 | 3.6 | 9 | <1 | 23 | 9 h 20 min |
| Year (annual) | 64°F | 40°F | 52.0°F | 47.43 | 13.0 | 102 | 28 | 111 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −8°C | −3.1°C | 86 mm | 13 cm |
| February | 5°C | −6°C | −0.6°C | 66 mm | 7 cm |
| March | 11°C | −1°C | 4.9°C | 84 mm | 3 cm |
| April | 19°C | 4°C | 11.6°C | 126 mm | 0 cm |
| May | 24°C | 10°C | 17.1°C | 128 mm | 0 cm |
| June | 29°C | 15°C | 21.7°C | 138 mm | 0 cm |
| July | 30°C | 17°C | 23.3°C | 119 mm | 0 cm |
| August | 29°C | 16°C | 22.4°C | 98 mm | 0 cm |
| September | 26°C | 12°C | 18.8°C | 80 mm | 0 cm |
| October | 19°C | 5°C | 12.3°C | 98 mm | 0 cm |
| November | 11°C | 0°C | 5.4°C | 99 mm | 1 cm |
| December | 4°C | −5°C | −0.6°C | 83 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00127522; 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 Rockville?
Normal highs sit between 65°F and 85°F in April, May, June, August, September and October. Of those, September has the fewest days with rain (6).
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 USC00127522.
When is the last frost in Rockville?
In Rockville, the last spring frost (32°F) comes after April 30 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 12 in half of years and before September 30 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 301 year in 10 after May 15; 9 in 10 after April 14
- First autumn frost, half of years before
- October 121 year in 10 before September 30; 9 in 10 before October 24
NOAA puts the median frost-free season at 164 days, and the season without a hard freeze (28°F) at 185 days.
A hard freeze (28°F) comes after April 18 in half of springs and before October 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rockville in zone 6a in ZIP code 47872, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Rockville's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°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 USC00127522; 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 Rockville?
In a normal year in Rockville, 28 days a year reach 90°F (1 of them 100°F or more), 111 nights fall to 32°F or colder and 102 days bring measurable precipitation.
- Days at 90°F or more
- 28a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 111a normal year
- Days that stay below freezing
- 27high of 32°F or less
- Days with 0.01 inch of precipitation
- 102a normal year
- Days with 1 inch of snow or more
- 5a normal year
The highest temperature in this station's record (since 1893) is 109°F, on July 14, 1936; the lowest is −25°F, on January 19, 1994.
The wettest calendar year on that record is 2018, with 65.08 in; the snowiest season is 1977–78, with 56.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00127522; records: ACIS (NOAA Regional Climate Centers), station USC00127522. Records use complete months only; a month missing more than three days is left out.
How sunny is Rockville?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Rockville, 4.0 kWh per square metre a day. August is the sunniest month (82%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.8 |
| February | 64% | 2.6 |
| March | 67% | 3.7 |
| April | 71% | 4.9 |
| May | 73% | 5.5 |
| June | 80% | 6.3 |
| July | 81% | 6.2 |
| August | 82% | 5.6 |
| September | 81% | 4.7 |
| October | 74% | 3.3 |
| November | 70% | 2.2 |
| December | 60% | 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 Rockville need?
A normal year in Rockville brings 5,635 heating degree days, 5% more than the median U.S. place (5,373), and 917 cooling degree days, 1% 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 3,402 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,195 | 0 |
| February | 956 | 0 |
| March | 752 | 2 |
| April | 380 | 12 |
| May | 145 | 72 |
| June | 20 | 199 |
| July | 3 | 279 |
| August | 5 | 231 |
| September | 79 | 107 |
| October | 349 | 16 |
| November | 698 | 1 |
| December | 1,054 | 0 |
| Year (annual) | 5,635 | 917 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00127522. 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 Rockville been warmer than normal lately?
2025 averaged 53.1°F, 1.1°F above the 1991-2020 normal of 52.0°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.5°F | +0.5°F | 54.22 | – |
| 2022 | 51.8°F | −0.2°F | 45.78 | – |
| 2023 | 54.0°F | +2.0°F | 34.75 | 2.3 |
| 2024 | 55.1°F | +3.1°F | 39.10 | 9.9 |
| 2025 | 53.1°F | +1.1°F | 33.51 | 26.1 |
Over 115 complete years from 1891 to 2025, the station's annual mean temperature rose at a fitted 1.1°F per century (+0.06°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00127522; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rockville's climate compare?
Rockville is warmer than 57 of the other 98 places with their own NOAA record in Indiana, and wetter than 69. Across the 7,247 U.S. stations with normals, its annual mean of 52.0°F is warmer than 49%.
In the Köppen classification computed from these normals, Rockville 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 Rockville share this climate record?
10 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.
- Montezuma, IN926 people · 8 mi W
- Rosedale, IN653 people · 10 mi S
- Waveland, IN439 people · 13 mi NE
- Mecca, IN278 people · 6 mi W
- Marshall, IN277 people · 6 mi N
- Bloomingdale, IN274 people · 5 mi N
- Hillsdale, IN195 people · 9 mi W
- Wallace, IN81 people · 16 mi N
- Bridgeton, IN68 people · 8 mi S
- Judson, IN29 people · 6 mi NE
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 Rockville's climate
What is the coldest month in Rockville?
January, with a normal high of 36°F and a normal low of 17°F. The warmest is July (86°F by day, 62°F at night).
Does it snow in Rockville?
Yes: 13 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in January (5.1 inches).
What is the rainiest month in Rockville?
June, with 5.45 in of precipitation in a normal year; the driest is February with 2.60 in.
What plant hardiness zone is Rockville in?
The USDA's 2023 map puts Rockville in zone 6a in ZIP code 47872, the nearest ZIP area. By the same method at Rockville's NOAA station, the coldest night of a typical year reaches −8°F (27 years, 1991-2020): zone 6a.
How late can frost come in Rockville?
In half of years the last 32°F night comes after April 30; 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
- Greencastle, IN21 miles from this station, 50.5°F a year
- Terre Haute, IN22 miles from this station, 53.5°F a year
- Paris, IL25 miles from this station, 51.4°F a year
- Perrysville, IN26 miles from this station, 52.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made