Hillsboro, Ohio climate: Normal weather by month, frost dates and records
Hillsboro's normal year runs from 19°F January nights to 85°F July afternoons, with 46.7 inches of precipitation and 18 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.3°C, January lows of −7°C, July highs of 29°C, 1,186 mm of precipitation a year.
- NOAA stationHillsboro
- Station IDUSC00333758
- Location39.23°N 83.61°W
- Elevation953 ft (291 m)
- Population6,599
On October 23, the normal high in Hillsboro is 64°F and the normal low 39°F, and the chance of measurable rain or snow is 34%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hillsboro.
- Jan 39° 19°
- Feb 43° 22°
- Mar 53° 29°
- Apr 65° 39°
- May 74° 50°
- Jun 82° 59°
- Jul 85° 62°
- Aug 83° 60°
- Sep 78° 53°
- Oct 67° 42°
- Nov 54° 32°
- Dec 43° 25°
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 Hillsboro each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 19°F. The most precipitation falls in May (5.06 in), the least in November (3.10 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 39°F | 19°F | 29.1°F | 3.44 | 6.9 | 13 | <1 | 26 | 9 h 40 min |
| February | 43°F | 22°F | 32.0°F | 3.26 | 5.0 | 12 | <1 | 23 | 10 h 40 min |
| March | 53°F | 29°F | 40.9°F | 4.20 | 3.4 | 13 | <1 | 18 | 11 h 50 min |
| April | 65°F | 39°F | 52.0°F | 4.85 | 0.2 | 13 | <1 | 6 | 13 h 10 min |
| May | 74°F | 50°F | 61.8°F | 5.06 | 0.0 | 14 | <1 | <1 | 14 h 20 min |
| June | 82°F | 59°F | 70.0°F | 4.82 | 0.0 | 12 | 2 | <1 | 14 h 50 min |
| July | 85°F | 62°F | 73.2°F | 4.25 | 0.0 | 11 | 4 | <1 | 14 h 40 min |
| August | 83°F | 60°F | 71.8°F | 3.72 | 0.0 | 10 | 2 | <1 | 13 h 50 min |
| September | 78°F | 53°F | 65.5°F | 3.17 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 67°F | 42°F | 54.3°F | 3.19 | 0.2 | 10 | <1 | 3 | 11 h 10 min |
| November | 54°F | 32°F | 42.7°F | 3.10 | 0.2 | 11 | <1 | 16 | 10 h |
| December | 43°F | 25°F | 33.8°F | 3.62 | 2.2 | 13 | <1 | 23 | 9 h 30 min |
| Year (annual) | 64°F | 41°F | 52.3°F | 46.68 | 18.1 | 141 | 10 | 115 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −7°C | −1.6°C | 87 mm | 18 cm |
| February | 6°C | −6°C | 0.0°C | 83 mm | 13 cm |
| March | 11°C | −1°C | 4.9°C | 107 mm | 9 cm |
| April | 18°C | 4°C | 11.1°C | 123 mm | 1 cm |
| May | 23°C | 10°C | 16.6°C | 129 mm | 0 cm |
| June | 28°C | 15°C | 21.1°C | 122 mm | 0 cm |
| July | 29°C | 17°C | 22.9°C | 108 mm | 0 cm |
| August | 29°C | 16°C | 22.1°C | 94 mm | 0 cm |
| September | 26°C | 12°C | 18.6°C | 81 mm | 0 cm |
| October | 19°C | 5°C | 12.4°C | 81 mm | 1 cm |
| November | 12°C | 0°C | 5.9°C | 79 mm | 1 cm |
| December | 6°C | −4°C | 1.0°C | 92 mm | 6 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00333758; 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 Hillsboro?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. Of those, September has the fewest days with rain (9).
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 USC00333758.
When is the last frost in Hillsboro?
In Hillsboro, the last spring frost (32°F) comes after April 24 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 6 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 241 year in 10 after May 11; 9 in 10 after April 10
- First autumn frost, half of years before
- October 201 year in 10 before October 6; 9 in 10 before November 1
NOAA puts the median frost-free season at 178 days, and the season without a hard freeze (28°F) at 201 days.
A hard freeze (28°F) comes after April 12 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hillsboro in zone 6b in ZIP code 45133, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Hillsboro's NOAA station is in zone 6b: the coldest night of a typical year reaches −3°F (24 complete years).
Frost dates for every NOAA station in Ohio · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00333758; 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 Hillsboro?
In a normal year in Hillsboro, 10 days a year reach 90°F, 115 nights fall to 32°F or colder and 141 days bring measurable precipitation.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 115a normal year
- Days that stay below freezing
- 29high of 32°F or less
- Days with 0.01 inch of precipitation
- 141a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1893) is 105°F, on July 4, 1897; the lowest is −30°F, on February 10, 1899.
The wettest calendar year on that record is 2011, with 62.93 in; the snowiest season is 1925–26, with 51.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00333758; records: ACIS (NOAA Regional Climate Centers), station USC00333758. Records use complete months only; a month missing more than three days is left out.
How sunny is Hillsboro?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hillsboro, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (57%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 58% | 1.8 |
| February | 62% | 2.6 |
| March | 65% | 3.6 |
| April | 71% | 4.9 |
| May | 73% | 5.6 |
| June | 78% | 6.2 |
| July | 79% | 6.0 |
| August | 81% | 5.5 |
| September | 79% | 4.6 |
| October | 72% | 3.2 |
| November | 69% | 2.2 |
| December | 57% | 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 Hillsboro need?
A normal year in Hillsboro brings 5,441 heating degree days, 1% more than the median U.S. place (5,373), and 829 cooling degree days, 9% 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 3,283 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,113 | 0 |
| February | 924 | 0 |
| March | 747 | 1 |
| April | 400 | 9 |
| May | 164 | 63 |
| June | 24 | 174 |
| July | 2 | 256 |
| August | 7 | 217 |
| September | 80 | 94 |
| October | 348 | 14 |
| November | 669 | 0 |
| December | 966 | 0 |
| Year (annual) | 5,441 | 829 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00333758. 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 Hillsboro been warmer than normal lately?
2024 averaged 55.3°F, 3.0°F above the 1991-2020 normal of 52.3°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.1°F | +0.8°F | 48.40 | – |
| 2022 | 51.7°F | −0.6°F | 47.82 | – |
| 2023 | 54.0°F | +1.7°F | 39.92 | – |
| 2024 | 55.3°F | +3.0°F | 42.76 | – |
Over 99 complete years from 1894 to 2025, the station's annual mean temperature rose at a fitted 2.8°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 USC00333758; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Hillsboro's climate compare?
Hillsboro is warmer than 65 of the other 98 places with their own NOAA record in Ohio, and wetter than 86. Across the 7,247 U.S. stations with normals, its annual mean of 52.3°F is warmer than 51%.
In the Köppen classification computed from these normals, Hillsboro 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 Hillsboro share this climate record?
8 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.
- Lynchburg, OH1,544 people · 9 mi W
- Leesburg, OH1,283 people · 8 mi N
- New Vienna, OH1,097 people · 8 mi NW
- Highland Holiday, OH1,004 people · 8 mi E
- Rocky Fork Point, OH868 people · 7 mi SE
- Highland, OH231 people · 8 mi N
- Sinking Spring, OH122 people · 16 mi SE
- Cynthiana, OH23 people · 15 mi E
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 Hillsboro's climate
What is the coldest month in Hillsboro?
January, with a normal high of 39°F and a normal low of 19°F. The warmest is July (85°F by day, 62°F at night).
Does it snow in Hillsboro?
Yes: 18 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (6.9 inches).
What is the rainiest month in Hillsboro?
May, with 5.06 in of precipitation in a normal year; the driest is November with 3.10 in.
What plant hardiness zone is Hillsboro in?
The USDA's 2023 map puts Hillsboro in zone 6b in ZIP code 45133, the nearest ZIP area. By the same method at Hillsboro's NOAA station, the coldest night of a typical year reaches −3°F (24 years, 1991-2020): zone 6b.
How late can frost come in Hillsboro?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ohio climateThe statewide normals and every place in the state
- Wilmington, OH17 miles from this station, 52.6°F a year
- Weather Office Wilmington, OH17 miles from this station, 53.7°F a year
- Washington Court House, OH23 miles from this station, 51.8°F a year
- Xenia, OH30 miles from this station, 53.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made