Power Outage Risk in Massachusetts

Massachusetts outage exposure spans the Charles-Merrimack-Connecticut river corridor inland and the South Shore-Cape Cod coastal strip, with riverine flooding, heavy snow, and named storms each contributing to multi-day outage risk across different utility service areas.

Massachusetts's NRI top hazard is Riverine Flooding — not hurricane. The state's practical outage pattern is led by severe storms, high winds, heavy snow, and river flooding, with hurricane declarations in the federal record reflecting offshore tracking systems rather than direct major landfalls.

10 federal declarations in 10 years, with Middlesex and Worcester as the primary BPI anchors of storm frequency and medical-device density (2014-2023)

FEMA National Risk Index (NRI)

92.3 / 100

Relatively Moderate

FEMA Declarations (2014-2023)

10 Major incidents

Highest Risk Window

Multi-season

Mixed Flood, Storm, and Coastal Outage Risk

JanJunDec

What drives outage risk in Massachusetts

Hurricane 93.2

FEMA Decl. 2

Winter Weather 54.5

FEMA Decl. —

Wildfire 50.9

FEMA Decl. —

Biological Not scored by NRI

FEMA Decl. 4

Why Massachusetts is different

Massachusetts's NOAA outage-event mix is led by thunderstorm wind (3,279 events), high wind (1,239), and strong wind (1,193) over the 2005-2024 analysis window — severe wind and winter storms dominate the practical outage record, not coastal hurricane surge. Riverine flooding adds a secondary driver across the Merrimack, Connecticut, and Quaboag river corridors.

Middlesex County (emPOWER: 6,938) and Worcester County (5,675) are the state's strongest BPI counties in both storm frequency and medical-backup sensitivity. Together they account for over 31% of the state's 40,363 electricity-dependent Medicare beneficiaries. Worcester County sits in the Central Plateau terrain zone where ice storms accumulate fastest and restoration crews have the longest travel distances from major dispatch points.

The Cape and Islands carry genuine hurricane surge exposure — a direct tropical strike on Buzzards Bay or Nantucket Sound would affect electricity infrastructure from Cape Cod through southeastern Massachusetts. But for the vast majority of Massachusetts households, the planning model should be sized for a multi-day nor'easter or ice storm rather than a Gulf Coast-style extended hurricane outage.

Notable Recent Events

Massachusetts Hurricane Lee (2023)

FEMA EM-3599 — emergency declaration for Hurricane Lee in Massachusetts, September 2023; one of 2 hurricane-related declarations in the 10-declaration federal record for the 2014-2023 window, alongside 2 severe-storm and 2 snowstorm declarations reflecting the state's mixed outage profile.

Source: FEMA EM-3599

Massachusetts Severe Winter Storm and Snowstorm (2022)

FEMA DR-4651 covers the January 2022 snowstorm in Massachusetts — a dense coastal state where snow, coastal wind, and cold-weather continuity pressure can stack infrastructure stress across the same high-population corridors that carry significant medical-device and storm-season exposure.

Source: FEMA DR-4651

Evidence trail

State source notes

These notes trace the editorial claims above back to FEMA, DOE, utility, or other cited records.

5 notes

1 OpenFEMA API

FEMA declaration count (10) from OpenFEMA API, deduplicated by disaster number, DR/EM/FM types, 2014-2023; Massachusetts's mix in this window includes Hurricane (2), Severe Storm (2), Snowstorm (2), and Biological (4).
2 FEMA NRI county layer

NRI composite score (92.3) from FEMA NRI county layer, population-weighted to state level; top modeled hazards are Riverine Flooding, Hurricane, and Earthquake.
3 NOAA Storm Events 2005-2024

NOAA outage-relevant event mix is led by Thunderstorm Wind (3,279), High Wind (1,239), Strong Wind (1,193), Flood (908), and Heavy Snow (876), with Middlesex, Norfolk, Worcester, and Berkshire leading county counts.
4 HHS emPOWER + GeneratorChecker BPI review

HHS emPOWER counts 40,363 electricity-dependent Medicare beneficiaries statewide; Middlesex (6,938), Worcester (5,675), Hampden (4,411), and Essex (4,279) are the strongest county anchors. Middlesex and Worcester are the top BPI counties in the GeneratorChecker cross-signal layer for both storm frequency and medical-backup sensitivity.
5 FEMA disaster records

Massachusetts Hurricane Lee EM-3599 and Massachusetts Severe Winter Storm and Snowstorm DR-4651 from FEMA declaration records.

Structured FEMA NRI, HHS emPOWER, NOAA Storm Events, and EIA methodology is documented separately on the methodology page.

NRI composite score of 92.3 reflects relatively moderate composite modeled hazard exposure; top modeled hazards are Riverine Flooding, Hurricane, and Earthquake, with 2 hurricane-related and 4 snowstorm and severe-storm declarations in the 10-declaration federal record for the 2014-2023 window..

Historical Storm Patterns in Massachusetts

NOAA storm-event records filtered to outage-relevant event types for Massachusetts. Counts reflect historical storm-event assignments, not confirmed utility outages.

Official data GeneratorChecker analysis

Analysis window

2005-01 to 2024-12

Included storm-event records

8,663

Source as of

2026-03

Included exact NOAA event types for Massachusetts: Thunderstorm Wind, Tornado, High Wind, Strong Wind, Flash Flood, Flood, Hurricane (Typhoon), Tropical Storm, Tropical Depression, Storm Surge/Tide, Winter Storm, Ice Storm, Freezing Rain, Heavy Snow, Blizzard.

Hazard seasonality

In this filtered NOAA record set for Massachusetts, Jul has the highest monthly count (1,467 records) , and Thunderstorm Wind is the leading event type. This chart shows frequency in NOAA records, not how severe a specific outage may be.

Sorted Jan–Dec

Jan 748

Feb 769

Mar 624

Apr 282

May 453

Jun 858

Jul 1,467

Aug 963

Sep 570

Oct 921

Nov 401

Dec 607

Top outage-relevant event types

1. Thunderstorm Wind 3,279
2. High Wind 1,239
3. Strong Wind 1,193
4. Flood 908
5. Heavy Snow 876
6. Winter Storm 486

Counties with highest historical outage-relevant storm event frequency

1. MIDDLESEX 1,137

59.5% of listed records were matched directly to this county.
2. NORFOLK 1,097

27.9% of listed records were matched directly to this county.
3. WORCESTER 1,017

63.6% of listed records were matched directly to this county.
4. BERKSHIRE 796

68.1% of listed records were matched directly to this county.
5. PLYMOUTH 748

28.2% of listed records were matched directly to this county.
6. ESSEX 715

51.9% of listed records were matched directly to this county.

Coverage and limitations

Forecast-zone events in Massachusetts are assigned to counties using the current NWS county crosswalk. Some forecast zones expand to multiple counties; unresolved legacy, coastal, and sub-county forecast zones fall into the excluded bucket.

Source notes NOAA Storm Events ↗

Direct county match

53.2%

Mapped from forecast zone

46.8%

Not assigned to county ranking

0.0%

Unresolved forecast zones

Forecast-zone events with no current NWS county crosswalk entry are excluded from county-level rankings.
Forecast-zone events are mapped with the current NWS county crosswalk, which may not exactly match historical zone boundaries across the full analysis window.
Counts reflect historical NOAA storm event records, not confirmed utility outage counts.
Marine event types remain excluded from this state contract even when coastal impacts may be operationally relevant.

Medical Outage Sensitivity in Massachusetts

County-level HHS emPOWER counts for electricity-dependent Medicare beneficiaries in Massachusetts.

Official data

40,363 Medicare beneficiaries in Massachusetts have claims associated with electricity-dependent medical equipment. (HHS emPOWER, 2026-03)

County-level HHS emPOWER records for this state. Medicare enrollment data only. 14 counties are included in this state snapshot.

Counties by total count

1. Middlesex 6,938
2. Worcester 5,675
3. Hampden 4,411
4. Essex 4,279
5. Bristol 3,957

Counties by share of Medicare beneficiaries

Counties with at least 1,000 Medicare beneficiaries

1. Hampden 4.1%
2. Worcester 3.2%
3. Franklin 3.1%
4. Bristol 3.0%
5. Hampshire 2.8%

GeneratorChecker analysis

Source notes HHS emPOWER Map ↗

Counties with higher concentrations may face elevated community-level demand for backup power during outages. This does not indicate individual medical necessity.

CPAP battery backup guide Oxygen concentrator backup guide

Limitations: Reflects Medicare beneficiaries with claims associated with electricity-dependent medical equipment. Does not capture non-Medicare or uninsured populations. HHS masks cells from 1 to 10 as 11.

GeneratorChecker BPI BPI v1.0 · NOAA 2005-2024 · HHS emPOWER 2026-03

Backup Priority Index in Massachusetts

The GeneratorChecker Backup Priority Index is a county shortlist for backup planning, combining historically frequent outage-relevant storm activity with larger county counts of electricity-dependent Medicare beneficiaries. It is planning context, not a forecast or an outage guarantee.

Official data GeneratorChecker analysis

BPI version

v1.0

Analysis window

2005-01 to 2024-12

Matched counties

Counties qualify for the public BPI only when both signals land at or above the 80th percentile within the state. The shortlist excludes low-base medical counties and counties with less than 30% direct NOAA county matching.

Qualifying counties shown on the page: 2.

Top BPI counties in this state

Percentiles are computed within Massachusetts only and are not comparable across states.

Source notes

1. MIDDLESEX

County FIPS 25017

Storm frequency · Top 1% statewide Medical exposure · Top 1% statewide

At-risk Medicare count

6,938

Storm-event records

1,137

Direct NOAA county match

59.5%
2. WORCESTER

County FIPS 25027

Storm frequency · Top 14% statewide Medical exposure · Top 7% statewide

At-risk Medicare count

5,675

Storm-event records

1,017

Direct NOAA county match

63.6%

How to read the BPI

BPI qualifies a county only when both the NOAA outage-relevant storm signal and the HHS emPOWER medical-count signal are at or above the 80th percentile within the state.
The medical signal uses total county count of electricity-dependent Medicare beneficiaries, not the share of beneficiaries within each county.
Counties with weak direct NOAA county matching stay out of the public BPI list even when their storm percentile is high.
Percentiles are computed within each state only and are not comparable across states.
The BPI is a planning layer. It does not claim a forecast, a utility reliability score, or an individualized medical-risk assessment.

Size your backup for Massachusetts

For Cape Cod and coastal southeastern Massachusetts, model a 48-hour hurricane or nor'easter scenario. For Worcester and Middlesex, a 48-hour ice storm or nor'easter scenario is the primary planning case.

48-hour nor'easter or ice storm backup

Primary Massachusetts scenario: major winter storm or nor'easter brings extended tree damage and ice accumulation across the interior and metro west corridor.

French Door Refrigerator WiFi Router CPAP Machine Gas Furnace Fan (Blower)

Load

1396W

Target

48h

Minimum

110,100 Wh

Worcester and Middlesex households should model this as the primary scenario. This scenario keeps a gas furnace or boiler blower running; it does not model electric resistance heating.

Size this scenario in calculator

24-hour severe storm essentials

Secondary scenario: severe thunderstorm or high-wind event with standard next-day restoration across most utility service areas.

French Door Refrigerator WiFi Router Laptop CPAP Machine

Load

698W

Target

24h

Minimum

27,600 Wh

Covers summer and fall severe-storm events. Cape Cod households should extend this window for coastal storm scenarios.

Size this scenario in calculator

Critical Note: No single portable power station in our database covers the full 48-hour baseline at this load (110,100 Wh target vs. 6,144 Wh max in our current database). Use solar recharge, load rotation, or expandable systems for longer events.

Common mistakes in Massachusetts

Focusing only on coastal hurricane risk while ignoring the ice storm and nor'easter exposure that affects Worcester and Middlesex counties.
Planning only for summer severe-storm events when nor'easters and ice storms create the most extended outages in Worcester and Middlesex counties.
Undersizing for medical-device loads when Middlesex County alone has nearly 7,000 electricity-dependent Medicare beneficiaries.

Top mistake: Sizing for a brief overnight outage when Worcester and Middlesex county households face multi-day nor'easter and ice storm events.

Go Deeper

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Data Sources & Methodology

NRI risk details

Composite score: 92.3 / 100

Rating: Relatively Moderate

Top modeled hazards: Riverine Flooding, Hurricane, Earthquake

Hurricane score: 93.2

Winter Weather score: 54.5

Wildfire score: 50.9

FEMA declaration breakdown

Total (2014-2023): 10

Most recent: 2023-09-15 Hurricane

Type	Count
Biological	4
Hurricane	2
Severe Storm	2
Snowstorm	2

Sizing formula

Required Wh = (Total Load W × Target Hours / Inverter Derate) × Safety Factor

Inverter derate: 0.70 (30% real-world loss)

Safety factor: 1.15

Rounding: Up to nearest 100 Wh

Historical utility-reported and modeled data. Your experience may vary.

Frequently Asked Questions

How high is outage risk in Massachusetts?

Massachusetts has an NRI composite risk score of 92.3 (Relatively Moderate), with 10 federal declarations from 2014 to 2023. NRI composite score of 92.3 reflects relatively moderate composite modeled hazard exposure; top modeled hazards are Riverine Flooding, Hurricane, and Earthquake, with 2 hurricane-related and 4 snowstorm and severe-storm declarations in the 10-declaration federal record for the 2014-2023 window..

What backup size should I target in Massachusetts?

For the primary scenario on this page (48-hour nor'easter or ice storm backup), the estimated minimum is 110,100 Wh for a 48-hour target. Refine this in the calculator with your actual devices.

Why do modeled risk and declaration history sometimes differ?

NRI is a modeled risk index based on hazard exposure, vulnerability, and expected loss. FEMA declarations reflect federally declared incidents. They answer different questions — use both signals together for planning.

What are the most common outage-planning mistakes in Massachusetts?

Sizing for a brief overnight outage when Worcester and Middlesex county households face multi-day nor'easter and ice storm events. See the common mistakes section above for more state-specific pitfalls.

Similar states: Connecticut , Rhode Island