Power outages in Massachusetts
In 2025, the average Massachusetts customer lost power for 2.0 hours (121.5 minutes) in total over the year. That is well below the US median of 4.3 hours (258.7 minutes) across the 50 states compared.
Trend
Total outage time was 5.3 hours (318.9 minutes) in 2020, peaked at 8.6 hours in 2021, then fell to 1.7 hours in 2024 before a small rise to 2.0 hours in 2025.
Utilities in 2025
The best utility by SAIDI in 2025 was Town of North Attleborough at 9.9 minutes (0.2 hours). The worst was Town of Shrewsbury at 830.5 minutes (13.8 hours).
| Utility | Customers | Hours / yr | Interruptions |
|---|---|---|---|
| Town of Shrewsbury - (MA) | 16,851 | 13.8 | 2.6 |
| City of Westfield - (MA) | 18,183 | 3.2 | 1.8 |
| Massachusetts Electric Co | 1,361,506 | 2.2 | 1.0 |
| City of Norwood - (MA) | 15,563 | 2.0 | 1.7 |
| NSTAR Electric Company | 1,463,349 | 1.9 | 0.8 |
| Nantucket Electric Co | 14,137 | 1.7 | 1.0 |
| Fitchburg Gas & Elec Light Co | 31,034 | 1.2 | 1.1 |
| Town of Braintree - (MA) | 16,623 | 1.2 | 1.3 |
| Town of Middleborough - (MA) | 16,361 | 1.1 | 0.9 |
| City of Taunton - (MA) | 39,801 | 1.1 | 1.4 |
| Town of Hudson - (MA) | 13,639 | 1.1 | 1.2 |
| Town of Reading - (MA) | 30,886 | 0.8 | 0.5 |
| Town of Danvers | 13,400 | 0.8 | 0.5 |
| Town of Wellesley - (MA) | 10,568 | 0.7 | 0.2 |
| City of Holyoke - (MA) | 17,671 | 0.6 | 0.5 |
| Town of Mansfield - (MA) | 10,555 | 0.3 | 0.1 |
| City of Chicopee - (MA) | 26,092 | 0.2 | 0.1 |
| Town of North Attleborough - (MA) | 13,940 | 0.2 | 0.1 |
What this means for backup power
For everyday outages, enter 2.2 hours in the calculator, which is the average length of one interruption. To ride out a year like 2021, size for 8.6 hours, the total outage time for that year.
FAQ
How long do power outages last in Massachusetts?
One interruption lasts 2.2 hours on average. Customers had about 0.9 interruptions per year in 2025.
What does SAIDI mean?
SAIDI is the total outage time per customer in a year. It is not the length of a single outage. In Massachusetts in 2025 it was 2.0 hours (121.5 minutes).
How much backup power time should I plan for?
For typical outages, plan around 2.2 hours. If you want cover for a year like 2021, the worst year in the data, plan for 8.6 hours of total outage time.
Utility pages
Source: U.S. EIA Form 861 Reliability file. Data snapshot 2026-11-05.