Cambridge, Massachusetts Flood Zones
Cambridge faces flooding from the Charles River and coastal storm surge propagating up the river. Low-lying areas along the river and near Alewife Brook are in mapped flood zones.
FEMA Flood Risk Profile: Middlesex County
Based on FEMA's National Risk Index, which evaluates flood risk at the county level using historical loss data, exposure, and vulnerability.
Inland Flood Risk
Relatively HighEst. annual loss: $224.4M
Coastal Flood Risk
Relatively LowEst. annual loss: $418K
Hurricane Risk
Relatively HighEst. annual loss: $30.1M
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
Federal Flood Disaster History: Middlesex (County)(in (P)MSA 1120,2600,4560) County
Middlesex (County)(in (P)MSA 1120,2600,4560) County has been included in 13 federal flood-related disaster declarations.
...and 5 earlier declarations since 1985.
These declarations affected communities across Middlesex (County)(in (P)MSA 1120,2600,4560) County, including Cambridge.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced February 2026.
NFIP Flood Insurance Claims: Middlesex County
Properties in Middlesex County have filed 3,749 NFIP flood insurance claims totaling $36.4M in payouts since 1978. The average claim payout is $10K.
Highest-Claim Years
2010
658 claims - $10.3M
1979
354 claims - $1.5M
2006
332 claims - $7.7M
Claims by Flood Zone
Zone X
1,244
Zone A
1,089
Zone AE
855
Zone V
11
Zone AO
7
Source: OpenFEMA NFIP Claims API. Data sourced February 2026.
Common Flood Zones in Cambridge
Properties in Cambridge, MA are commonly designated in these FEMA flood zones:
What Your Flood Zone Means in Cambridge
Cambridge faces multiple inland flood threats, including riverine flooding from nearby waterways and flash flooding from intense rainfall overwhelming urban drainage systems. Properties near river corridors face the highest risk, but stormwater backup can affect neighborhoods well outside the mapped floodplain. The most common FEMA flood zone designations in Cambridge are Zone AE, Zone AO, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $224.4M. Cambridge has Zone AO areas subject to sheet-flow flooding, where shallow water spreads across broad, flat terrain rather than channeling through waterways.
With both riverine and urban stormwater flood risk, insurance costs in Cambridge depend heavily on a property's elevation relative to nearby waterways and the local drainage infrastructure. FEMA's Risk Rating 2.0 prices in multiple inland flood sources rather than relying on the flood zone line alone. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.
Flood zone boundaries in Cambridge can shift when FEMA updates its Flood Insurance Studies or when upstream development changes how water moves through the watershed. New stormwater infrastructure or dam modifications can also trigger map revisions. Use our free lookup tool to check the current flood zone for any Cambridge address.
Flood Insurance Discount: Cambridge
Cambridge participates in FEMA's Community Rating System (CRS), a voluntary program that rewards communities for flood mitigation efforts beyond minimum NFIP requirements. Residents in the Special Flood Hazard Area may qualify for reduced flood insurance premiums.
CRS Class
Class 9
SFHA Premium Discount
5% off
CRS classes range from 1 (best) to 10 (no discount). Cambridge's Class 9 rating means NFIP policyholders in the SFHA can receive up to a 5% discount on their flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Source: FEMA Community Rating System, October 2025. Discounts apply to NFIP policies only.
Check Your Cambridge Address
Enter any Cambridge, MA address to instantly see its FEMA flood zone, risk level, and whether flood insurance is required.
Free Flood Zone LookupCambridge, MA Flood Zone FAQ
What flood zones are in Cambridge, MA?
The most common FEMA flood zones in Cambridge are Zone AE, Zone AO, Zone X. Properties in these high-risk zones (SFHA) may require flood insurance with a federally regulated or government-backed mortgage.
Is flood insurance required in Cambridge?
If your Cambridge property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance. Properties in Zone X are not federally required to carry flood insurance, though coverage is still recommended since about 25% of all NFIP flood claims come from Zone X properties.
How do I check my flood zone in Cambridge?
Enter your Cambridge address in the search tool above for an instant flood zone determination. Results include your FEMA flood zone, SFHA status, base flood elevation (if available), and FIRM panel information, pulled directly from FEMA's National Flood Hazard Layer.
Does Cambridge offer flood insurance discounts?
Yes. Cambridge participates in FEMA's Community Rating System (CRS) with a Class 9 rating, qualifying residents in the Special Flood Hazard Area for up to a 5% discount on NFIP flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Has Cambridge experienced major flooding events?
Middlesex (County)(in (P)MSA 1120,2600,4560) County, where Cambridge is located, has been part of 13 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Hurricane Lee in 2023. Federal disaster declarations are issued when flooding overwhelms local resources and triggers FEMA assistance programs.
How many flood insurance claims have been filed in Cambridge?
Middlesex County has recorded 3,749 NFIP flood insurance claims totaling $36.4M in payouts since 1978. The year with the most claims was 2010, with 658 claims and $10.3M in payouts. These figures cover all NFIP claims in the county, including Cambridge.
Sources
This page summarizes information from FEMA and other official resources in plain language. For full technical details, see the links below.
- FEMA National Flood Hazard LayerDirect Source
The NFHL is the source of all flood zone data shown on this page.
- FEMA Map Service Center — Search by AddressDirect Source
Look up any address to view FIRM panels, FIS reports, and LOMCs.
- NFHL Data and Map StatusTopic Page
View NFHL coverage and data freshness by state and community.
- FEMA National Risk Index — Data ResourcesDirect Source
County-level risk scores for inland flooding, coastal flooding, and hurricane used in the Flood Risk Profile.
- OpenFEMA Disaster Declarations Summaries API v2Direct Source
Federal disaster declarations filtered for flood-related incident types (Flood, Hurricane, Severe Storm, Coastal Storm).
- OpenFEMA FIMA NFIP Claims API v2Direct Source
Historical NFIP flood insurance claims since 1978, aggregated by county and state. Includes claim counts, payouts, and flood zone breakdowns.
Sources last verified: February 2026