Wilmington New Castle County, DE Climate: Temperature & Rain by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Wilmington New Castle County's primary NOAA station, WILMINGTON NEW CASTLE CO AP.
The climate verdict for Wilmington New Castle County
Water is the standout signal in Wilmington New Castle County, Delaware: 45.3 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 56°F. Its climate comfort score of 73/100 (good) lands mid-pack nationally, exceeding 66% of station-mapped location scores.
- 56°F
- yearly average temperature, NOAA normal
- 73/100
- comfort score, above 66% of station-mapped location scores
- 45.3"
- annual precipitation · 20" snow
- 208 days
- frost-free growing season
Wilmington New Castle County: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00013781 · Wilmington New Castle County, DE 56°F mean · 45.3" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-MID · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 56°F
- RANK-UPPER #4,254
- PHOTO-FINISH ≈ W Plains
- PRCP-MID 45.3"
- SWING-MID 44°F
- COMF-MID 73/100
- LOAD-HEAT 4,647 HDD
- STN-1 USW00013781
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: W Plains, MO (+ 0.1 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every DE station list.
- Wilmington New… (this station) 56°F
- Hot Alton, MO 56°F
- Near W Plains, MO 56°F
- Near S Point, OH 56°F
- Near Washington DC D…, VA 56°F
Climate Living Index · Wilmington New Castle County
Wilmington New Castle County: 66/100 · grade C
Wilmington New Castle County publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Wilmington New Castle County, not an official NOAA rating. Rankings still use Comfort Score 73/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 93 calendar days | 78/100 · B |
| Frost-free season | 208 days/year | 70/100 · B |
| Precipitation balance | 45.3 in · 10.3 from 35 in | 64/100 · C |
| Annual temperature balance | 55.5°F · 12.0° from 67.5°F | 61/100 · C |
| Snowfall burden | 20.2 inches/year | 49/100 · D |
Wilmington New Castle County · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Wilmington New Castle County is a temperate Köppen climate: Cfa
Coldest-month mean 33.5°F and warmest-month mean 77.6°F place this station in temperate, no dry season, hot summer climates (Cfa). Class Cfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, no dry season, hot summer.
- Köppen code
- Cfa
- Group
- Temperate
- Warmest month
- 77.6°F
- Coldest month
- 33.5°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Wilmington New Castle County sits across the climate record
Three NOAA fields for Wilmington New Castle County's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 62nd percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 69th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- 54th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Wilmington New Castle County compares across U.S. station-mapped locations
Wilmington New Castle County's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
73 Top 34% score exceeds 66% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). This entry sits in this band.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Wilmington New Castle County's measured station temperature trend
MethodologyAcross 76 complete annual observations from 1932 to 2025, WILMINGTON NEW CASTLE CO AP warmed at a fitted rate of 0.25°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Wilmington New Castle County primary station fitted change +0.25 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 41°F (5°C) | 26°F (-4°C) | 34°F (1°C) | 3.2" | 6.1" | 23.6 | 0.0 |
| February | 44°F (7°C) | 27°F (-3°C) | 36°F (2°C) | 2.8" | 7.8" | 21.2 | 0.0 |
| March | 53°F (11°C) | 34°F (1°C) | 43°F (6°C) | 4.2" | 3.1" | 14.2 | 0.0 |
| April | 64°F (18°C) | 44°F (6°C) | 54°F (12°C) | 3.5" | 0.1" | 2.0 | 0.1 |
| May | 74°F (23°C) | 53°F (12°C) | 64°F (18°C) | 3.6" | 0.0" | 0.0 | 1.1 |
| June | 82°F (28°C) | 63°F (17°C) | 73°F (23°C) | 4.7" | 0.0" | 0.0 | 3.9 |
| July | 87°F (30°C) | 68°F (20°C) | 78°F (25°C) | 4.4" | 0.0" | 0.0 | 9.6 |
| August | 85°F (29°C) | 67°F (19°C) | 76°F (24°C) | 4.0" | 0.0" | 0.0 | 5.7 |
| September | 79°F (26°C) | 59°F (15°C) | 69°F (21°C) | 4.4" | 0.0" | 0.0 | 1.9 |
| October | 67°F (19°C) | 47°F (8°C) | 57°F (14°C) | 3.7" | 0.0" | 0.6 | 0.1 |
| November | 56°F (13°C) | 37°F (3°C) | 47°F (8°C) | 3.1" | 0.2" | 9.9 | 0.0 |
| December | 46°F (8°C) | 30°F (-1°C) | 38°F (3°C) | 3.9" | 2.9" | 20.1 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 87°F around July 10, short of 90°F on every date, while 93 dates carry a normal low at or below freezing, the coldest 25°F near January 23.
The freezing stretch
The normal low stays at or below 32°F into March 9, then returns to freezing around December 8, covering 93 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is May 9, when 39% of years recorded at least a hundredth of an inch. The driest is August 30 at 27%. Summed across the calendar, that is about 122 wet dates a year.
The widest day
April 24 carries the biggest normal gap between afternoon and dawn, 21°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Wilmington New Castle County.
Where Wilmington New Castle County Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 21°F.
Wilmington New Castle County earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 6.1"
10.8 days with precipitation
Snow: 7.8"
10.0 days with precipitation
Snow: 3.1"
11.2 days with precipitation
Snow: 0.1"
11.1 days with precipitation
11.7 days with precipitation
11.0 days with precipitation
10.0 days with precipitation
8.9 days with precipitation
8.8 days with precipitation
8.9 days with precipitation
Snow: 0.2"
8.8 days with precipitation
Snow: 2.9"
10.6 days with precipitation
Wilmington New Castle County spreads its precipitation across the year
Neither half of the year dominates here: June through August take 29% of the annual total and December through February 22%, with neither reaching the 35% that would mark a distinct wet season. Wilmington New Castle County has no dry season to plan around, though it does carry a 44.1°F seasonal spread.
The gap between the wettest and driest month still matters: June averages 4.7" and February 2.8". The three wettest months together take 30% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
When it rains in Wilmington New Castle County, it arrives in quantity
45.3" of precipitation falls across only about 122 wet days here, averaging 0.37 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 122 a year, 33% of all days
- Average depth per wet day
- 0.37 inches
- Most wet days
- May, about 12
- Fewest wet days
- September, about 9
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Winter brings real snow to Wilmington New Castle County
Wilmington New Castle County averages 20.2 inches of snowfall a year, with February the snowiest month on the normals, spread across roughly 11 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 20.2 inches of depth.
- Days recording measurable snow: about 11 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 4% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
November 1
50% probability date
Last Spring Freeze
April 7
50% probability date
Growing Season
208 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,647
Higher = more heating needed
Cooling Degree Days
1,228
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside DE closest to Wilmington New Castle County on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (56°F here).
- Allardt, TN 56°F · 0.0°F off
- Castle Valley, UT 56°F · 0.0°F off
- Hayesville, NC 56°F · 0.0°F off
- Hillsboro, IL 56°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (45.3" here), excluding temperature-peer places.
- Mineola, NY 45.3" · 0.0" off
- Biglerville, PA 45.3" · 0.0" off
- Ashland, VA 45.3" · 0.0" off
- Millinocket, ME 45.4" · 0.0" off
Snow and freeze rhythm
When cold and snow define Wilmington New Castle County
heating led · wet · mid swing
Wilmington New Castle County's energy balance leans toward cold weather: 4,647 annual heating degree days against 1,228 for cooling. Its 44.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
Wilmington New Castle County's frost-free season lasts about 208 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Wilmington New Castle County coldest normal
January
The monthly mean of 34°F (1°C) sits near freezing, so cold nights and above-freezing afternoons share the same month.
-
2. Wilmington New Castle County typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Wilmington New Castle County snow peak
February
Wilmington New Castle County averages 20.2 inches of snow a year, with February the snowiest month on the normals.
Questions about Wilmington New Castle County's climate
How much snow does Wilmington New Castle County get? ▼
How cold does Wilmington New Castle County get in winter? ▼
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Wilmington New Castle County's primary station: WILMINGTON NEW CASTLE CO AP (USW00013781). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Wilmington New Castle County; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Wilmington New Castle County comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.