Climate Risk Summary

Norwalk, CT Risk Profile

The primary drivers of climate-related financial risk in Norwalk, CT are Inland Flooding, Hurricane, and Coastal Flooding.

City-Wide Aggregation

These scores represent the population-weighted average across all residential blocks in Norwalk.

Primary Risks

Inland Flooding

$21,081,940

Expected Annual Loss for Norwalk

64.6Score

Very High compared to US average

Norwalk

Minimal Estimated LossMax Estimated Loss

Hurricane

$6,421,560

Expected Annual Loss for Norwalk

86.5Score

Relatively High compared to US average

Norwalk

Minimal Estimated LossMax Estimated Loss

Coastal Flooding

$1,875,200

Expected Annual Loss for Norwalk

39.0Score

Very High compared to US average

Norwalk

Minimal Estimated LossMax Estimated Loss

City Boundary

Legend

Very Low

Low

Moderate

High

Very High

Extreme

Financial Risk Inventory

MAJOR DRIVER

Inland Flooding

$21,081,940

Score: 64.6

MAJOR DRIVER

Hurricane

$6,421,560

Score: 86.5

MAJOR DRIVER

Coastal Flooding

$1,875,200

Score: 39.0

Earthquake

$1,168,564

Score: 61.2

Strong Wind

$783,637

Score: 72.7

Heat Wave

$328,530

Score: 25.6

Cold Wave

$258,994

Score: 27.3

Tornado

$270,600

Score: 26.1

Ice Storm

$146,584

Score: 59.6

Lightning

$113,798

Score: 32.5

Winter Weather

$87,995

Score: 63.2

Hail

$22,601

Score: 23.3

Wildfire

$546

Score: 15.5

Landslide

$157

Score: 55.1

Recommended investments to protect your property value and reduce insurance liability based on your local risk profile.

💧Medium Investment

Inland Flooding Mitigation

Install a smart sump pump with battery backup and extend downspouts 10ft from foundation.

Risk Score: 64.6

🌀High Investment

Hurricane Mitigation

Install permanent hurricane shutters or upgrade to impact-resistant windows.

Risk Score: 86.5

🏠Low Investment

Earthquake Mitigation

General property maintenance and insurance review recommended.

Risk Score: 61.2

💨Low Investment

Strong Wind Mitigation

Trim large trees back from the roofline and reinforce roof-to-wall connectors (hurricane straps).

Risk Score: 72.7

❄️Medium Investment

Ice Storm Mitigation

Install a 10kWh backup battery system to keep pipes from freezing during grid failure.

Risk Score: 59.6

🏠Low Investment

Winter Weather Mitigation

General property maintenance and insurance review recommended.

Risk Score: 63.2

⛰️High Investment

Landslide Mitigation

Professional slope stabilization and foundation drainage inspection is highly recommended.

Risk Score: 55.1

Sources and Methodology

Spatial Aggregation

Our "Atlas" risk scores are derived using a population-weighted spatial join. Because US Zip Codes and Census Tracts do not share perfectly aligned boundaries, a simple geographic average would be misleading. We utilize US Census Block Group population statistics to identify where residents actually live within a Zip Code. We then intersect these points with FEMA National Risk Index (NRI) hazard data to calculate a weighted exposure score.

Financial Projections (EAL)

Expected Annual Loss (EAL) estimates the average economic impact of natural hazards in dollars per year. This calculation incorporates three components: Exposure (the value of structures and agriculture), Annualized Frequency (historical probability), and Historic Loss Ratio (vulnerability of the area).

Primary Data Sources

FEMA National Risk IndexHazard frequency and loss data (v1.20.0 - Dec 2025)
U.S. Census BureauTIGER/Line 2025 Shapefiles & Decennial Population

Nearby Cities

Compo Darien Downtown Noroton Noroton Heights Old Hill

Zip Codes in Norwalk

06850 06851 06853 06854 06855 06880