Wilmington, Ohio climate: Normal weather by month, frost dates and records
Wilmington's normal year runs from 21°F January nights to 84°F July afternoons, with 42.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.4°C, January lows of −6°C, July highs of 29°C, 1,077 mm of precipitation a year.
- NOAA stationWilmington Air Park
- Station IDUSW00013841
- Location39.42°N 83.82°W
- Elevation1,056 ft (322 m)
- Population12,639
On October 23, the normal high in Wilmington is 62°F and the normal low 41°F, and the chance of measurable rain or snow is 36%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Wilmington.
- Jan 37° 21°
- Feb 41° 24°
- Mar 51° 32°
- Apr 64° 42°
- May 73° 52°
- Jun 82° 60°
- Jul 84° 63°
- Aug 83° 61°
- Sep 77° 54°
- Oct 65° 44°
- Nov 52° 34°
- Dec 41° 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 in Wilmington each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 21°F. The most precipitation falls in June (4.64 in), the least in February (2.73 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 37°F | 21°F | 29.1°F | 2.91 | 13 | <1 | 26 | 9 h 40 min |
| February | 41°F | 24°F | 32.2°F | 2.73 | 12 | <1 | 23 | 10 h 40 min |
| March | 51°F | 32°F | 41.2°F | 3.63 | 12 | <1 | 17 | 11 h 50 min |
| April | 64°F | 42°F | 52.7°F | 4.46 | 13 | <1 | 5 | 13 h 10 min |
| May | 73°F | 52°F | 62.5°F | 4.63 | 14 | <1 | <1 | 14 h 20 min |
| June | 82°F | 60°F | 70.9°F | 4.64 | 13 | 3 | <1 | 15 h |
| July | 84°F | 63°F | 73.6°F | 3.88 | 12 | 6 | <1 | 14 h 40 min |
| August | 83°F | 61°F | 72.0°F | 3.16 | 11 | 3 | <1 | 13 h 50 min |
| September | 77°F | 54°F | 65.6°F | 2.93 | 11 | 2 | <1 | 12 h 30 min |
| October | 65°F | 44°F | 54.5°F | 3.20 | 11 | <1 | 3 | 11 h 10 min |
| November | 52°F | 34°F | 42.9°F | 3.05 | 11 | <1 | 14 | 10 h |
| December | 41°F | 27°F | 34.0°F | 3.18 | 13 | <1 | 22 | 9 h 20 min |
| Year (annual) | 62°F | 43°F | 52.6°F | 42.40 | 145 | 14 | 110 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 3°C | −6°C | −1.6°C | 74 mm |
| February | 5°C | −5°C | 0.1°C | 69 mm |
| March | 10°C | 0°C | 5.1°C | 92 mm |
| April | 18°C | 5°C | 11.5°C | 113 mm |
| May | 23°C | 11°C | 16.9°C | 118 mm |
| June | 28°C | 16°C | 21.6°C | 118 mm |
| July | 29°C | 17°C | 23.1°C | 99 mm |
| August | 28°C | 16°C | 22.2°C | 80 mm |
| September | 25°C | 12°C | 18.7°C | 74 mm |
| October | 18°C | 7°C | 12.5°C | 81 mm |
| November | 11°C | 1°C | 6.1°C | 77 mm |
| December | 5°C | −3°C | 1.1°C | 81 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Wilmington's own co-op station Wilmington (3 mi N) does: 23 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013841; 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 Wilmington?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. Of those, August 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 USW00013841.
When is the last frost in Wilmington?
In Wilmington, the last spring frost (32°F) comes after April 19 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 8 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 191 year in 10 after May 6; 9 in 10 after April 5
- First autumn frost, half of years before
- October 221 year in 10 before October 8; 9 in 10 before November 3
NOAA puts the median frost-free season at 185 days, and the season without a hard freeze (28°F) at 208 days.
A hard freeze (28°F) comes after April 6 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts 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, Wilmington's NOAA station is in zone 6b: the coldest night of a typical year reaches −4°F (21 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 USW00013841; 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 Wilmington?
In a normal year in Wilmington, 14 days a year reach 90°F, 110 nights fall to 32°F or colder and 145 days bring measurable precipitation.
- Days at 90°F or more
- 14a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 110a normal year
- Days that stay below freezing
- 30high of 32°F or less
- Days with 0.01 inch of precipitation
- 145a normal year
The highest temperature in Wilmington's official record (kept by the National Weather Service since 1917) is 111°F, on July 21, 1934; the lowest is −25°F, on January 18, 1982.
The wettest calendar year on that record is 1929, with 61.61 in; the snowiest season is 1950–51, with 75.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00013841; records: ACIS (NOAA Regional Climate Centers), NWS threaded record ILNthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Wilmington?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around 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 much heating and cooling does Wilmington need?
A normal year in Wilmington brings 5,364 heating degree days, 0% fewer than the median U.S. place (5,373), and 881 cooling degree days, 3% 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 3,368 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,113 | 0 |
| February | 918 | 0 |
| March | 739 | 1 |
| April | 379 | 8 |
| May | 145 | 69 |
| June | 18 | 195 |
| July | 2 | 270 |
| August | 6 | 223 |
| September | 78 | 97 |
| October | 343 | 16 |
| November | 663 | 0 |
| December | 960 | 0 |
| Year (annual) | 5,364 | 881 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013841. 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 Wilmington been warmer than normal lately?
2025 averaged 52.9°F, 0.3°F above the 1991-2020 normal of 52.6°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.0°F | +1.4°F | 42.46 |
| 2022 | 53.6°F | +1.0°F | 41.85 |
| 2023 | 56.0°F | +3.4°F | 42.92 |
| 2024 | 56.9°F | +4.3°F | 38.47 |
| 2025 | 52.9°F | +0.3°F | 44.24 |
Source: observed years: ACIS, station USW00013841. A year counts only with all twelve months complete.
How does Wilmington's climate compare?
Wilmington is warmer than 70 of the other 98 places with their own NOAA record in Ohio, and wetter than 60. Across the 7,247 U.S. stations with normals, its annual mean of 52.6°F is warmer than 52%.
In the Köppen classification computed from these normals, 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 Wilmington share this climate record?
6 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.
- Blanchester, OH4,226 people · 12 mi SW
- Martinsville, OH407 people · 7 mi S
- Roachester, OH369 people · 15 mi W
- Fayetteville, OH317 people · 17 mi S
- Midland, OH300 people · 9 mi SW
- St. Martin, OH133 people · 15 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.
What do Wilmington's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Wilmington. This page uses Wilmington Air Park; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Wilmington (3 mi N) USC00339219 | 5 mi N | 1,033 ft | 51.9°F | 20°F | 84°F | 43.2 | 23 | April 20 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Wilmington's climate
What is the coldest month in Wilmington?
January, with a normal high of 37°F and a normal low of 21°F. The warmest is July (84°F by day, 63°F at night).
Does it snow in Wilmington?
Yes. NOAA publishes no 1991-2020 snowfall normal for Wilmington's NOAA station; Wilmington's own co-op station Wilmington (3 mi N) records 23 inches of snow in a normal year.
What is the rainiest month in Wilmington?
June, with 4.64 in of precipitation in a normal year; the driest is February with 2.73 in.
What plant hardiness zone is Wilmington in?
The USDA's 2023 map puts Wilmington in zone 6b in ZIP code 45177, the nearest ZIP area. By the same method at Wilmington's NOAA station, the coldest night of a typical year reaches −4°F (21 years, 1991-2020): zone 6b.
How late can frost come in Wilmington?
In half of years the last 32°F night comes after April 19; in one year in ten it comes after May 6. Waiting until May 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wilmington in OctoberThis month day by day, its records and recent years
- Ohio climateThe statewide normals and every place in the state
- Weather Office Wilmington, OH0 miles from this station, 53.7°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