Henlopen Acres · Weather, flooding and hazards

Henlopen Acres, Delaware: weather, flooding and hazards

Weather, climate, flooding and hazards in Henlopen Acres, Sussex County, Delaware: 20 questions answered from NOAA, the state and other official sources.

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Questions about weather, flooding and hazards in Henlopen Acres

What is the climate like in Henlopen Acres, Delaware?

Using NOAA 1991 to 2020 climate normals from the Lewes station, the nearest of the stations we use, the average January low is 30.2 degrees F and the average July high is 87.7 degrees F. Annual precipitation averages 47.28 inches. The station is not inside Henlopen Acres, so readings in town can differ a little, especially near the water. Source: ncei.noaa.gov.

How much snow does Henlopen Acres get per year?

The 1991 to 2020 normal for the Lewes station, the nearest station we use, is 10.5 inches of snow a year. Individual winters vary a lot around that average. Source: ncei.noaa.gov.

Is Henlopen Acres in a flood zone?

Part of Henlopen Acres may sit in a FEMA Special Flood Hazard Area, and the answer depends on the address, so we do not give a town-wide yes or no. The USGS elevation at the town's Census center point is only about 17 feet, which is low ground. Look up a specific property in the FEMA Flood Map Service Center and the DNREC Delaware Flood Planning Tool. Source: msc.fema.gov, floodplanning.dnrec.delaware.gov, epqs.nationalmap.gov.

Is Henlopen Acres in a hurricane evacuation zone?

Delaware labels hurricane evacuation zones A, B, C and D, and describes them as low-lying areas susceptible to flooding and storm surge. The state page does not list communities by zone, so we cannot say which zone Henlopen Acres or a given address falls in. Use the Know Your Zone lookup tool or interactive map to check an address. Source: preparede.org, dema.delaware.gov.

What body of water is Henlopen Acres on?

The Atlantic Ocean forms the eastern edge of Henlopen Acres, and the Lewes and Rehoboth Canal forms its northwest and west boundary. Source: archives.delaware.gov.

How big is Henlopen Acres and how high above sea level is it?

The 2020 Census Gazetteer lists Henlopen Acres at 0.255 square miles of land and 0 square miles of water. Elevation at the Census center point is about 17 feet above sea level (USGS 3DEP), and ground height varies across town. Source: www2.census.gov, epqs.nationalmap.gov.

Which National Weather Service forecast zone covers Henlopen Acres?

The National Weather Service (Mount Holly office) places Henlopen Acres in forecast zone DEZ004, Delaware Beaches, Delaware. This was read from the NWS point forecast page for the town's Census center point. Source: forecast.weather.gov.

How much of Henlopen Acres is in the FEMA floodplain?

The 2025 comprehensive plan update says the FEMA 100-year floodplain covers nearly the entire area from Zwaanendael to the beach, plus portions of Broad Hollow and Tidewaters. It gives no percentage, so check an address on the FEMA map service center. Source: henlopenacres.delaware.gov.

When did Henlopen Acres get its current FEMA flood maps?

The 2025 comprehensive plan update says revised flood insurance rate maps took effect March 16, 2015. Source: henlopenacres.delaware.gov.

What freeboard does Henlopen Acres require?

The Town's floodplain ordinance includes a 36-inch freeboard requirement, according to the 2025 comprehensive plan update. Source: henlopenacres.delaware.gov.

Is Henlopen Acres planning for sea level rise?

The 2025 plan proposes a Resiliency Subcommittee to study sea level rise effects on property, the water plant and wells, the marina and stormwater. The Town may restrict new permanent structures within 5 feet of expected sea level rise. It gives no specific projection. Source: henlopenacres.delaware.gov.

What protects the Henlopen Acres beach from storms?

The Beach Club jetty extends 320 feet, and the comprehensive plan recommends an engineering inspection every five years, annual dune grass planting and prompt sand fence repairs for the Block W dunes. Source: henlopenacres.delaware.gov.

Is the Lewes and Rehoboth Canal dredged near Henlopen Acres?

The canal forms the Town's western boundary and falls under Army Corps of Engineers jurisdiction. The 2025 plan says a 90,000 cubic yard maintenance dredge was planned for 2025 in two phases. Source: henlopenacres.delaware.gov.

How is stormwater handled in Henlopen Acres?

The Town lies in the Inland Bays watershed and the stormwater system was built out in 2005, with tie-ins in 2010, per the 2025 plan. Sandy Bottoms serves as a drainage outfall and needs regular maintenance. Source: henlopenacres.delaware.gov.

Was Henlopen Acres included in Hurricane Irene and Sandy evacuations?

Yes. Sussex County's August 2011 Irene evacuation listed Henlopen Acres along the Route 1 corridor, and Delaware's October 2012 Sandy order listed it among flood-prone ocean communities. Source: sussexcountyde.gov, news.delaware.gov.

How many days a year reach 90 degrees F near Henlopen Acres?

NOAA 1991 to 2020 normals for the Lewes station list 29.2 days a year with a high of 90 F or more and 59.1 days with a low of 32 F or colder. The station is not in Henlopen Acres. Source: ncei.noaa.gov.

What is the annual mean temperature near Henlopen Acres?

At the Lewes station, NOAA 1991 to 2020 normals list 58.5 F as the annual mean, with July averaging 79.2 F and January 38.2 F. Source: ncei.noaa.gov.

When does it snow near Henlopen Acres?

At the Lewes station, February is the snowiest month at 6.5 inches in the 1991 to 2020 normals, followed by January at 2.0 and 1.0 inch each in March and December. Source: ncei.noaa.gov.

How much sea level rise does Delaware plan for by 2100?

Delaware Geological Survey lists planning scenarios relative to 2000 of 1.71 ft (low), 3.25 ft (intermediate) and 5.02 ft (high) by 2100, from the 2017 DNREC committee. Source: dgs.udel.edu.

How fast is sea level rising at Lewes, the nearest NOAA tide gauge?

NOAA's Tides and Currents data list a Lewes trend of 1.49 inches per decade for 1919 to 2025, with an uncertainty of 0.05 inches per decade. Source: api.tidesandcurrents.noaa.gov.

How these answers are sourced

Every answer on this page cites an official or primary source, such as the town, a state agency, NOAA or the institution itself. Answers SussexCounty.ai could not confirm from a primary source are left out until they can be.