Weather Office Wilmington, Ohio climate: Climate normals at a NOAA weather station
Weather Office Wilmington's normal year runs from 22°F January nights to 85°F July afternoons, with 44.7 inches of precipitation and 27 inches of snow 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, 1,135 mm of precipitation a year.
- NOAA stationWeather Office Wilmington
- Station IDUSC00339220
- Location39.42°N 83.82°W
- Elevation1,053 ft (321 m)
On October 23, the normal high in Weather Office Wilmington is 64°F and the normal low 42°F, and the chance of measurable rain or snow is 33%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Weather Office Wilmington.
- Jan 38° 22°
- Feb 42° 24°
- Mar 52° 33°
- Apr 65° 43°
- May 75° 53°
- Jun 83° 61°
- Jul 85° 64°
- Aug 84° 62°
- Sep 79° 55°
- Oct 67° 44°
- Nov 54° 34°
- Dec 43° 27°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Weather Office Wilmington each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 22°F. The most precipitation falls in May (4.81 in), the least in February (2.94 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 38°F | 22°F | 30.1°F | 3.25 | 8.9 | 14 | <1 | 25 | 9 h 40 min |
| February | 42°F | 24°F | 33.4°F | 2.94 | 7.4 | 12 | <1 | 22 | 10 h 40 min |
| March | 52°F | 33°F | 42.4°F | 4.05 | 4.1 | 12 | <1 | 16 | 11 h 50 min |
| April | 65°F | 43°F | 53.8°F | 4.47 | 0.4 | 13 | <1 | 5 | 13 h 10 min |
| May | 75°F | 53°F | 63.9°F | 4.81 | 0.0 | 14 | 1 | <1 | 14 h 20 min |
| June | 83°F | 61°F | 71.9°F | 4.53 | 0.0 | 13 | 4 | <1 | 15 h |
| July | 85°F | 64°F | 74.6°F | 4.13 | 0.0 | 11 | 6 | <1 | 14 h 40 min |
| August | 84°F | 62°F | 73.0°F | 3.42 | 0.0 | 10 | 4 | <1 | 13 h 50 min |
| September | 79°F | 55°F | 66.7°F | 3.03 | 0.0 | 9 | 2 | <1 | 12 h 30 min |
| October | 67°F | 44°F | 55.5°F | 3.36 | 0.1 | 10 | <1 | 3 | 11 h 10 min |
| November | 54°F | 34°F | 44.0°F | 3.28 | 1.1 | 11 | <1 | 14 | 10 h |
| December | 43°F | 27°F | 34.9°F | 3.43 | 4.6 | 13 | <1 | 22 | 9 h 20 min |
| Year (annual) | 64°F | 44°F | 53.7°F | 44.70 | 26.6 | 142 | 17 | 105 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −1.1°C | 83 mm | 23 cm |
| February | 6°C | −4°C | 0.8°C | 75 mm | 19 cm |
| March | 11°C | 0°C | 5.8°C | 103 mm | 10 cm |
| April | 18°C | 6°C | 12.1°C | 114 mm | 1 cm |
| May | 24°C | 12°C | 17.7°C | 122 mm | 0 cm |
| June | 28°C | 16°C | 22.2°C | 115 mm | 0 cm |
| July | 30°C | 18°C | 23.7°C | 105 mm | 0 cm |
| August | 29°C | 17°C | 22.8°C | 87 mm | 0 cm |
| September | 26°C | 13°C | 19.3°C | 77 mm | 0 cm |
| October | 19°C | 7°C | 13.1°C | 85 mm | 0 cm |
| November | 12°C | 1°C | 6.7°C | 83 mm | 3 cm |
| December | 6°C | −3°C | 1.6°C | 87 mm | 12 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00339220; 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.
Which months are mildest at Weather Office Wilmington?
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 (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 USC00339220.
When is the last frost at Weather Office Wilmington?
In Weather Office Wilmington, the last spring frost (32°F) comes after April 17 in half of years and after May 4 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 9 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 171 year in 10 after May 4; 9 in 10 after April 3
- First autumn frost, half of years before
- October 221 year in 10 before October 9; 9 in 10 before November 3
NOAA puts the median frost-free season at 187 days, and the season without a hard freeze (28°F) at 211 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Weather Office Wilmington in zone 6b in ZIP code 45177, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6b: the coldest night of a typical year reaches −3°F (26 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 USC00339220; 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 at Weather Office Wilmington?
In a normal year in Weather Office Wilmington, 17 days a year reach 90°F, 105 nights fall to 32°F or colder and 142 days bring measurable precipitation.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 105a normal year
- Days that stay below freezing
- 28high of 32°F or less
- Days with 0.01 inch of precipitation
- 142a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1995) is 99°F, on June 28, 2012; the lowest is −14°F, on February 24, 2015.
The wettest calendar year on that record is 2011, with 57.01 in; the snowiest season is 1995–96, with 54.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00339220; records: ACIS (NOAA Regional Climate Centers), station USC00339220. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Weather Office Wilmington?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds at Weather Office Wilmington, 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 many heating and cooling degree days does Weather Office Wilmington record?
A normal year at Weather Office Wilmington brings 5,110 heating degree days, 5% fewer than the median U.S. place (5,373), and 1,019 cooling degree days, 12% 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 3,605 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,082 | 0 |
| February | 886 | 0 |
| March | 703 | 2 |
| April | 351 | 15 |
| May | 123 | 90 |
| June | 13 | 220 |
| July | 2 | 301 |
| August | 5 | 254 |
| September | 67 | 116 |
| October | 316 | 20 |
| November | 632 | 1 |
| December | 932 | 0 |
| Year (annual) | 5,110 | 1,019 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00339220. 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.
Have recent years at Weather Office Wilmington been warmer than normal?
2025 averaged 53.3°F, 0.4°F below the 1991-2020 normal of 53.7°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 54.5°F | +0.8°F | 40.04 | 28.9 |
| 2022 | 54.0°F | +0.3°F | 43.41 | 14.6 |
| 2023 | 55.9°F | +2.2°F | 41.72 | 11.0 |
| 2024 | 56.0°F | +2.3°F | 41.30 | 12.6 |
| 2025 | 53.3°F | −0.4°F | 46.46 | 36.2 |
Source: observed years: ACIS, station USC00339220. A year counts only with all twelve months complete.
How does Weather Office Wilmington's climate compare?
Weather Office Wilmington is warmer than 84 of the 99 places with their own NOAA record in Ohio, and wetter than 80. Across the 7,247 U.S. stations with normals, its annual mean of 53.7°F is warmer than 56%.
In the Köppen classification computed from these normals, Weather Office Wilmington 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 Weather Office Wilmington share this climate record?
2 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.
- Sabina, OH2,465 people · 11 mi NE
- Clarksville, OH536 people · 9 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 Weather Office Wilmington's climate
What is the coldest month at Weather Office Wilmington?
January, with a normal high of 38°F and a normal low of 22°F. The warmest is July (85°F by day, 64°F at night).
Does it snow at Weather Office Wilmington?
Yes: 27 inches in a normal year, falling on 26 days with 0.1 inch or more, the most in January (8.9 inches).
What is the rainiest month at Weather Office Wilmington?
May, with 4.81 in of precipitation in a normal year; the driest is February with 2.94 in.
What plant hardiness zone is Weather Office Wilmington in?
The USDA's 2023 map puts Weather Office Wilmington in zone 6b in ZIP code 45177, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −3°F (26 years, 1991-2020): zone 6b.
How late can frost come at Weather Office Wilmington?
In half of years the last 32°F night comes after April 17; in one year in ten it comes after May 4. Waiting until May 4 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, OH0 miles from this station, 52.6°F a year
- Xenia, OH14 miles from this station, 53.7°F a year
- Hillsboro, OH17 miles from this station, 52.3°F a year
- Washington Court House, OH22 miles from this station, 51.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made