Hamilton, Ohio climate: Normal weather by month, frost dates and records
Hamilton's normal year runs from 22°F January nights to 87°F July afternoons, with 41.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.1°C, January lows of −6°C, July highs of 30°C, 1,052 mm of precipitation a year.
- NOAA stationHamilton Butler County Regional Airport
- Station IDUSW00053855
- Location39.36°N 84.52°W
- Elevation634 ft (193 m)
- From the center3 miles
- Population63,953
On October 14, the normal high in Hamilton is 69°F and the normal low 43°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hamilton.
- Jan 40° 22°
- Feb 44° 23°
- Mar 54° 32°
- Apr 67° 42°
- May 75° 52°
- Jun 83° 61°
- Jul 87° 64°
- Aug 86° 62°
- Sep 80° 54°
- Oct 68° 42°
- Nov 55° 32°
- Dec 44° 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 Hamilton each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 22°F. The most precipitation falls in April (4.63 in), the least in February (2.41 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 22°F | 30.7°F | 2.91 | 11 | <1 | 25 | 9 h 40 min |
| February | 44°F | 23°F | 33.6°F | 2.41 | 11 | <1 | 23 | 10 h 40 min |
| March | 54°F | 32°F | 42.8°F | 3.49 | 12 | <1 | 17 | 11 h 50 min |
| April | 67°F | 42°F | 54.1°F | 4.63 | 13 | <1 | 5 | 13 h 10 min |
| May | 75°F | 52°F | 63.6°F | 4.59 | 15 | 1 | <1 | 14 h 20 min |
| June | 83°F | 61°F | 71.9°F | 4.06 | 13 | 5 | <1 | 15 h |
| July | 87°F | 64°F | 75.5°F | 3.67 | 13 | 10 | <1 | 14 h 40 min |
| August | 86°F | 62°F | 74.1°F | 2.95 | 11 | 8 | <1 | 13 h 50 min |
| September | 80°F | 54°F | 66.7°F | 3.04 | 12 | 4 | <1 | 12 h 30 min |
| October | 68°F | 42°F | 54.8°F | 3.17 | 11 | <1 | 5 | 11 h 10 min |
| November | 55°F | 32°F | 43.2°F | 3.16 | 10 | <1 | 17 | 10 h |
| December | 44°F | 26°F | 34.6°F | 3.34 | 13 | <1 | 23 | 9 h 20 min |
| Year (annual) | 65°F | 43°F | 53.8°F | 41.42 | 143 | 28 | 115 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −6°C | −0.7°C | 74 mm |
| February | 7°C | −5°C | 0.9°C | 61 mm |
| March | 12°C | 0°C | 6.0°C | 89 mm |
| April | 19°C | 5°C | 12.3°C | 118 mm |
| May | 24°C | 11°C | 17.6°C | 117 mm |
| June | 28°C | 16°C | 22.2°C | 103 mm |
| July | 30°C | 18°C | 24.2°C | 93 mm |
| August | 30°C | 17°C | 23.4°C | 75 mm |
| September | 26°C | 12°C | 19.3°C | 77 mm |
| October | 20°C | 5°C | 12.7°C | 81 mm |
| November | 13°C | 0°C | 6.2°C | 80 mm |
| December | 6°C | −4°C | 1.4°C | 85 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Cheviot (15 miles away), gets 16 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00053855; 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 Hamilton?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, October has the fewest days with rain (11).
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 USW00053855.
When is the last frost in Hamilton?
In Hamilton, the last spring frost (32°F) comes after April 22 in half of years and after May 10 in one year in ten; the first autumn frost comes before October 18 in half of years and before October 5 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 221 year in 10 after May 10; 9 in 10 after April 6
- First autumn frost, half of years before
- October 181 year in 10 before October 5; 9 in 10 before October 29
NOAA puts the median frost-free season at 178 days, and the season without a hard freeze (28°F) at 200 days.
A hard freeze (28°F) comes after April 8 in half of springs and before October 27 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hamilton in zone 6b in ZIP code 45015. By the map's own method, the average of each year's coldest night over 1991-2020, Hamilton's NOAA station is in zone 6a: the coldest night of a typical year reaches −5°F (22 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 Ohio · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00053855; 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 Hamilton?
In a normal year in Hamilton, 28 days a year reach 90°F, 115 nights fall to 32°F or colder and 143 days bring measurable precipitation.
- Days at 90°F or more
- 28a 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
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 143a normal year
The highest temperature in this station's record (since 1997) is 105°F, on July 7, 2012; the lowest is −20°F, on February 24, 2015.
The wettest calendar year on that record is 2011, with 60.21 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00053855; records: ACIS (NOAA Regional Climate Centers), station USW00053855. Records use complete months only; a month missing more than three days is left out.
How sunny is Hamilton?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hamilton, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (58%). Among the 459 U.S. places of 50,000 or more, that ranks tied 385th (with 30 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.8 |
| February | 62% | 2.6 |
| March | 65% | 3.6 |
| April | 71% | 4.9 |
| May | 72% | 5.5 |
| 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 | 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 Hamilton need?
A normal year in Hamilton brings 5,111 heating degree days, 5% fewer than the median U.S. place (5,373), and 1,067 cooling degree days, 18% 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 3,637 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,063 | 0 |
| February | 881 | 0 |
| March | 689 | 3 |
| April | 341 | 14 |
| May | 126 | 82 |
| June | 14 | 219 |
| July | 1 | 328 |
| August | 3 | 286 |
| September | 66 | 117 |
| October | 333 | 17 |
| November | 655 | 1 |
| December | 941 | 0 |
| Year (annual) | 5,111 | 1,067 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00053855. 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 Hamilton been warmer than normal lately?
2025 averaged 53.8°F, equal to the 1991-2020 normal of 53.8°F. 2 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.7°F | +0.9°F | 42.49 |
| 2022 | 53.8°F | at normal | 40.28 |
| 2024 | 57.6°F | +3.9°F | – |
| 2025 | 53.8°F | at normal | – |
Source: observed years: ACIS, station USW00053855. A year counts only with all twelve months complete.
How does Hamilton's climate compare?
Hamilton is warmer than 85 of the other 98 places with their own NOAA record in Ohio, and wetter than 46. Across the 7,247 U.S. stations with normals, its annual mean of 53.8°F is warmer than 56%.
In the Köppen classification computed from these normals, Hamilton 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 Hamilton share this climate record?
16 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.
- Mason, OH36,046 people · 12 mi E
- Forest Park, OH20,033 people · 5 mi S
- Trenton, OH14,131 people · 9 mi N
- Sharonville, OH14,040 people · 9 mi SE
- Springdale, OH11,183 people · 6 mi SE
- Beckett Ridge, OH9,451 people · 5 mi E
- Woodlawn, OH3,913 people · 8 mi S
- Four Bridges, OH3,407 people · 9 mi E
- Lincoln Heights, OH3,139 people · 9 mi SE
- Glendale, OH2,282 people · 7 mi SE
- New Miami, OH2,276 people · 5 mi N
- Wetherington, OH1,317 people · 8 mi E
- Williamsdale, OH806 people · 5 mi N
- Seven Mile, OH743 people · 9 mi N
- Woodsdale, OH682 people · 5 mi NE
- Olde West Chester, OH357 people · 7 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 Hamilton's climate
What is the coldest month in Hamilton?
January, with a normal high of 40°F and a normal low of 22°F. The warmest is July (87°F by day, 64°F at night).
Does it snow in Hamilton?
Yes. NOAA publishes no 1991-2020 snowfall normal for Hamilton's NOAA station; the nearest record that keeps one, Cheviot (15 miles away), records 16 inches of snow in a normal year.
What is the rainiest month in Hamilton?
April, with 4.63 in of precipitation in a normal year; the driest is February with 2.41 in.
What plant hardiness zone is Hamilton in?
The USDA's 2023 map puts Hamilton in zone 6b in ZIP code 45015. By the same method at Hamilton's NOAA station, the coldest night of a typical year reaches −5°F (22 years, 1991-2020): zone 6a.
How late can frost come in Hamilton?
In half of years the last 32°F night comes after April 22; in one year in ten it comes after May 10. Waiting until May 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ohio climateThe statewide normals and every place in the state
- Fairfield, OH4 miles from this station, 53.6°F a year
- Cheviot, OH16 miles from this station, 53.8°F a year
- Mack, OH17 miles from this station, 53.6°F a year
- Franklin, OH17 miles from this station, 52.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made