Wilmington, Delaware climate: Normal weather by month, frost dates and records
Wilmington's normal year runs from 26°F January nights to 87°F July afternoons, with 45.3 inches of precipitation and 20 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.1°C, January lows of −4°C, July highs of 30°C, 1,151 mm of precipitation a year.
- NOAA stationWilmington Airport
- Station IDUSW00013781
- Location39.67°N 75.60°W
- Elevation79 ft (24 m)
- From the center6 miles
- Population73,176
On October 14, the normal high in Wilmington is 68°F and the normal low 48°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Wilmington.
- Jan 41° 26°
- Feb 44° 27°
- Mar 53° 34°
- Apr 64° 44°
- May 74° 53°
- Jun 82° 63°
- Jul 87° 68°
- Aug 85° 67°
- Sep 79° 59°
- Oct 67° 47°
- Nov 56° 37°
- Dec 46° 30°
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 87°F; January the coldest, with normal lows of 26°F. The most precipitation falls in June (4.67 in), the least in February (2.83 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. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 26°F | 33.5°F | 3.23 | 6.1 | 11 | <1 | 24 | 9 h 40 min |
| February | 44°F | 27°F | 35.5°F | 2.83 | 7.8 | 10 | <1 | 21 | 10 h 40 min |
| March | 53°F | 34°F | 43.2°F | 4.16 | 3.1 | 11 | <1 | 14 | 11 h 50 min |
| April | 64°F | 44°F | 53.9°F | 3.51 | 0.1 | 11 | <1 | 2 | 13 h 10 min |
| May | 74°F | 53°F | 63.5°F | 3.57 | 0.0 | 12 | 1 | <1 | 14 h 20 min |
| June | 82°F | 63°F | 72.6°F | 4.67 | 0.0 | 11 | 4 | <1 | 15 h |
| July | 87°F | 68°F | 77.6°F | 4.41 | 0.0 | 10 | 10 | <1 | 14 h 40 min |
| August | 85°F | 67°F | 75.8°F | 3.98 | 0.0 | 9 | 6 | <1 | 13 h 50 min |
| September | 79°F | 59°F | 68.9°F | 4.38 | 0.0 | 9 | 2 | <1 | 12 h 30 min |
| October | 67°F | 47°F | 57.2°F | 3.68 | 0.0 | 9 | <1 | 1 | 11 h 10 min |
| November | 56°F | 37°F | 46.6°F | 3.06 | 0.2 | 9 | <1 | 10 | 10 h |
| December | 46°F | 30°F | 38.2°F | 3.85 | 2.9 | 11 | <1 | 20 | 9 h 20 min |
| Year (annual) | 65°F | 46°F | 55.5°F | 45.33 | 20.2 | 122 | 22 | 92 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −4°C | 0.8°C | 82 mm | 15 cm |
| February | 7°C | −3°C | 1.9°C | 72 mm | 20 cm |
| March | 11°C | 1°C | 6.2°C | 106 mm | 8 cm |
| April | 18°C | 6°C | 12.2°C | 89 mm | 0 cm |
| May | 23°C | 12°C | 17.5°C | 91 mm | 0 cm |
| June | 28°C | 17°C | 22.6°C | 119 mm | 0 cm |
| July | 30°C | 20°C | 25.3°C | 112 mm | 0 cm |
| August | 29°C | 19°C | 24.3°C | 101 mm | 0 cm |
| September | 26°C | 15°C | 20.5°C | 111 mm | 0 cm |
| October | 19°C | 8°C | 14.0°C | 93 mm | 0 cm |
| November | 13°C | 3°C | 8.1°C | 78 mm | 1 cm |
| December | 8°C | −1°C | 3.4°C | 98 mm | 7 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013781; 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, 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 USW00013781.
When is the last frost in Wilmington?
In Wilmington, the last spring frost (32°F) comes after April 7 in half of years and after April 21 in one year in ten; the first autumn frost comes before November 1 in half of years and before October 19 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 71 year in 10 after April 21; 9 in 10 after March 26
- First autumn frost, half of years before
- November 11 year in 10 before October 19; 9 in 10 before November 15
NOAA puts the median frost-free season at 209 days, and the season without a hard freeze (28°F) at 234 days.
A hard freeze (28°F) comes after March 27 in half of springs and before November 14 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Wilmington in zone 7b across its 5 ZIP code areas (7b in 19801, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Wilmington's NOAA station is in zone 7b: the coldest night of a typical year reaches 7°F (30 complete years).
Frost dates for every NOAA station in Delaware · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00013781; 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.
What hardiness zone is each Wilmington ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Wilmington's 5 ZIP code areas are all in zone 7b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Wilmington?
In a normal year in Wilmington, 22 days a year reach 90°F, 92 nights fall to 32°F or colder and 122 days bring measurable precipitation.
- Days at 90°F or more
- 22a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 92a normal year
- Days that stay below freezing
- 14high of 32°F or less
- Days with 0.01 inch of precipitation
- 122a normal year
- Days with 1 inch of snow or more
- 5a normal year
The highest temperature in Wilmington's official record (kept by the National Weather Service since 1894) is 107°F, on August 7, 1918; the lowest is −15°F, on February 9, 1934.
The wettest calendar year on that record is 2018, with 61.37 in; the snowiest season is 2009–10, with 72.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00013781; records: ACIS (NOAA Regional Climate Centers), NWS threaded record ILGthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Wilmington?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Wilmington, 4.1 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (68%). Among the 459 U.S. places of 50,000 or more, that ranks tied 304th (with 25 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 2.0 |
| February | 71% | 2.9 |
| March | 69% | 3.8 |
| April | 73% | 5.0 |
| May | 72% | 5.6 |
| June | 78% | 6.2 |
| July | 82% | 6.2 |
| August | 80% | 5.4 |
| September | 77% | 4.4 |
| October | 73% | 3.2 |
| November | 74% | 2.3 |
| December | 68% | 1.8 |
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 4,647 heating degree days, 14% fewer than the median U.S. place (5,373), and 1,228 cooling degree days, 35% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,841 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 976 | 0 |
| February | 825 | 0 |
| March | 677 | 1 |
| April | 347 | 13 |
| May | 122 | 74 |
| June | 13 | 241 |
| July | 0 | 389 |
| August | 1 | 334 |
| September | 38 | 155 |
| October | 266 | 23 |
| November | 551 | 0 |
| December | 832 | 0 |
| Year (annual) | 4,647 | 1,228 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013781. 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 56.0°F, 0.5°F above the 1991-2020 normal of 55.5°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 56.9°F | +1.4°F | 38.03 | 11.6 |
| 2022 | 56.4°F | +0.9°F | 43.17 | 10.8 |
| 2023 | 57.7°F | +2.2°F | 52.09 | 1.1 |
| 2024 | 57.1°F | +1.6°F | 43.03 | 11.0 |
| 2025 | 56.0°F | +0.5°F | 40.52 | 14.7 |
Over 76 complete years from 1932 to 2025, the station's annual mean temperature rose at a fitted 4.5°F per century (+0.25°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00013781; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Wilmington's climate compare?
Wilmington is warmer than 1 of the other 5 places with their own NOAA record in Delaware, and wetter than 1. Across the 7,247 U.S. stations with normals, its annual mean of 55.5°F is warmer than 62%.
In the Köppen classification computed from these normals, Wilmington is Cfa: temperate, 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?
9 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.
- Pennsville, NJ12,238 people · 6 mi E
- Wilmington Manor, DE8,030 people · 1 mi NE
- New Castle, DE5,715 people · 2 mi E
- Salem, NJ5,369 people · 10 mi SE
- Delaware City, DE1,933 people · 7 mi S
- St. Georges, DE1,564 people · 8 mi S
- Alloway, NJ1,473 people · 16 mi SE
- Quinton, NJ463 people · 13 mi SE
- Hancocks Bridge, NJ296 people · 14 mi SE
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 Airport; the other differs by site and elevation, and the linked ones have pages of their own:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Wilmington Porter Research USC00079605 | 3 mi N | 270 ft | 53.4°F | 24°F | 84°F | 50.3 | 12 | April 7 |
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 41°F and a normal low of 26°F. The warmest is July (87°F by day, 68°F at night).
Does it snow in Wilmington?
Yes: 20 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in February (7.8 inches).
What is the rainiest month in Wilmington?
June, with 4.67 in of precipitation in a normal year; the driest is February with 2.83 in.
What plant hardiness zone is Wilmington in?
The USDA's 2023 map puts Wilmington in zone 7b across its 5 ZIP code areas (7b in 19801, the largest). By the same method at Wilmington's NOAA station, the coldest night of a typical year reaches 7°F (30 years, 1991-2020): zone 7b.
How late can frost come in Wilmington?
In half of years the last 32°F night comes after April 7; in one year in ten it comes after April 21. Waiting until April 21 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
- Delaware climateThe statewide normals and every place in the state
- Wilmington Porter Research, DE7 miles from this station, 53.4°F a year
- Newark, DE7 miles from this station, 55.7°F a year
- Marcus Hook, PA14 miles from this station, 57.1°F a year
- Avondale, PA16 miles from this station, 52.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made