New Castle County Climate
New Castle County, Delaware
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
54.9°F
Annual Precip
47.5"
Annual Snowfall
16.1"
Extreme Heat Days
24
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
7b
Minimum winter temperature range for plant survival
3,709
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: New Castle County
Climate Verdict
New Castle County has a mild, with an average annual temperature of 54.9°F, moderately wet with 47.5 inches of annual precipitation, occasional hot days — 24.100000000000005 per year above 90°F, light snow averaging 16.1 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are cold, with January averaging 32.7°F. summers are warm — July averages 76.9°F. The 44°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for New Castle County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
New Castle County closely matches the Delaware statewide average temperature of 56.4°F.
Climate Profile
About New Castle County Weather
Matching the national temperature median
At 54.9°F annually, New Castle County aligns closely with the national median temperature for U.S. counties. It offers a balanced four-season climate that avoids the extreme heat found further south.
Delaware’s coolest county
New Castle is Delaware’s coolest county, falling 1.5 degrees below the state average of 56.4°F. While the rest of the state leans warmer, this northern corridor maintains a more temperate profile year-round.
Chillier than southern neighbors
The county is significantly cooler than its southern neighbor Kent, which averages 57.1°F. It also receives 16.1 inches of snow, the highest volume in Delaware, distinguishing it from the sandier coastal regions.
The state's snowiest winters
Winter brings a chilly January average of 32.7°F, contributing to the state's most robust snowfall totals. Summers remain warm with 24 days over 90°F, though the July average of 76.9°F is the lowest in the state.
Prepare for freezing temperatures
Reliable heating and insulation are vital as winter temperatures frequently dip below freezing. Residents should also invest in snow shovels or blowers to manage the county's 16.1-inch annual snow accumulation.
Frequently Asked Questions
What is the average temperature in New Castle County?
How much rain does New Castle County get?
Does it snow in New Castle County?
How hot does New Castle County get in summer?
How cold are winters in New Castle County?
Track your own weather in New Castle County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
Other Counties in Delaware
Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.