This interactive map shows FEMA flood zones across Connecticut, drawn directly from the National Flood Hazard Layer (NFHL). Connecticut faces flood risk from two distinct sources: coastal storm surge and tidal flooding along its shoreline, plus inland (riverine) flooding from rivers, creeks, and heavy rainfall. Use the map to see Special Flood Hazard Areas, coastal V and VE zones (where applicable), the 500-year (Zone X) floodplain, and regulatory floodways – the data is identical to what underwrites the National Flood Insurance Program.

Flood risk overview for Connecticut

• Inland (riverine) flood risk: FEMA rates Connecticut as Relatively Moderate, with an expected annual loss of $858.5 million/year from rivers, creeks, and rainfall flooding.
• Coastal flood risk: FEMA rates Connecticut as Relatively Moderate, with an expected annual loss of $31.1 million/year from storm surge and tidal flooding along the coast.
• Combined flood expected annual loss across Connecticut: $889.5 million per year, based on FEMA’s December 2025 National Risk Index.
• Population in mapped flood-exposed areas: roughly 135,914 Connecticut residents in inland flood zones and 153,882 along the coast.
• Recorded historical flood events: 289 inland flood events in the NRI source record.

FEMA’s National Risk Index ratings range from Very Low through Very High. Ratings reflect the state’s expected annual economic loss from each hazard, normalised against the rest of the country.

Interactive map of Connecticut flood zones

The map below opens centred on Connecticut. FEMA flood zone polygons load at zoom level 11 and above – this is a hard limit set by the source dataset, which contains over 51 GB of polygon geometry. Use the +/- controls or scroll to zoom in until polygons appear, then pan to any address in the state. Click a polygon for the full zone designation, SFHA status, and base flood elevation where available.

Connecticut counties with the highest flood risk

FEMA’s National Risk Index aggregates flood loss expectations to the county level. The Connecticut counties below carry the largest combined inland + coastal expected annual loss from flooding:

Recent flood-related federal disaster declarations in Connecticut

Federal disaster declarations covering flood, severe storm, hurricane, and coastal storm events affecting Connecticut in the last decade. Each declaration unlocks federal Public Assistance, Individual Assistance, and Hazard Mitigation funding for the designated counties.

• DR-4820 (Sep 2024): Severe Storm, Flooding, Landslides, And Mudslides – 3 designated counties/areas
• DR-3612 (Aug 2024): Severe Storms, Flooding, Landslides, And Mudslides – 3 designated counties/areas
• DR-3604 (Jan 2024): Severe Storms, Flooding, And A Potential Dam Breach – 3 designated counties/areas
• DR-4629 (Oct 2021): Remnants Of Hurricane Ida – 7 designated counties/areas
• DR-3564 (Aug 2021): Hurricane Henri – 10 designated counties/areas
• DR-4580 (Jan 2021): Tropical Storm Isaias – 10 designated counties/areas
• DR-3535 (Aug 2020): Tropical Storm Isaias – 10 designated counties/areas
• DR-4410 (Dec 2018): Severe Storms And Flooding – 2 designated counties/areas

Source: OpenFEMA Disaster Declarations Summaries.

How to look up the FEMA flood zone for a Connecticut address

The map on this page is for general orientation. For an authoritative flood zone determination on any specific Connecticut property – which is what mortgage lenders, insurance underwriters, and permitting offices use – go to the FEMA Map Service Center, search by address, and download the effective Flood Insurance Rate Map (FIRM) or generate a FIRMette for that location. This is the only legally recognised flood zone determination in Connecticut.

Flood zone categories on the Connecticut map

• Floodway – the channel of a river plus floodplain that must remain clear to carry the base flood. Construction in floodways is severely restricted across Connecticut.
• Zone AE – the most common Special Flood Hazard Area in Connecticut. Has a published Base Flood Elevation. Mandatory flood insurance for federally backed mortgages.
• Zone A – SFHA without a published base flood elevation; common in less-studied parts of Connecticut. An engineer or surveyor must determine the elevation.
• Zone AH / AO – shallow flooding zones (1-3 ft of ponded water or sheet flow).
• Zone V / VE – coastal high-hazard areas with wave action. Coastal V and VE zones (the highest-risk category, with wave action) appear along the Connecticut shoreline.
• Zone X (shaded) – the 0.2% annual chance (500-year) floodplain. Insurance optional but risk is not zero.

Flood insurance in Connecticut

If a Connecticut property carries a federally backed mortgage and sits inside an SFHA zone (any A or V zone), flood insurance is mandatory. Properties outside the SFHA can buy NFIP coverage on a voluntary basis, often at a much lower premium. FEMA’s Risk Rating 2.0 system now prices NFIP premiums based on each individual property’s flood risk – distance to water, elevation, replacement cost – rather than zone alone, so two homes in the same zone can have very different premiums.

Frequently asked questions

What does “1% annual chance” mean for Connecticut flood zones?

A 1% annual chance flood (the “100-year flood”) has a 1% probability of occurring in any single year. Over a 30-year mortgage, that compounds to roughly a 26% probability of at least one such flood at the property. SFHA zones in Connecticut are defined by this 1% threshold.

How current are the Connecticut flood maps shown here?

The polygons come from FEMA’s National Flood Hazard Layer, which FEMA updates on a rolling basis as individual communities complete new flood studies. Some Connecticut communities have very recent maps; others may be running on FIRMs that are 10-20 years old. The effective date is shown in the FEMA Map Service Center for each panel.

Why is my Connecticut property not in a flood zone but still flooded?

FEMA flood maps cover riverine and coastal flooding from named flood sources. They do not show pluvial (urban surface-water) flooding from extreme rainfall, sewer back-up, or drainage failure. A significant fraction of US flood losses each year happen outside mapped SFHAs – which is why FEMA encourages flood insurance even for Connecticut properties in Zone X.

Flood zone maps for nearby states

• New York flood zones map
• Massachusetts flood zones map
• Rhode Island flood zones map
• New Jersey flood zones map

Sources

• FEMA National Flood Hazard Layer – the source of all polygon geometry shown on the map.
• FEMA National Risk Index v1.20 (December 2025) – state and county expected annual loss figures.
• OpenFEMA Disaster Declarations Summaries – federal disaster declarations.
• FEMA Map Service Center – authoritative effective FIRM lookup.
• Mapscaping national FEMA Flood Zones map – the full US-wide version of this tool.