County annual report · FIPS 25017
2025 Middlesex County, MA Power Outage Report
In 2025, customers in Middlesex County, MA went without power for an average of 4.0 hours, a total of 1.7M customer-hours (Massachusetts average 2.8 hours). That ranks 5th worst of 14 Massachusetts counties and 1777th of 3,000 nationally.
Compared with MA, the US and 2024
Coverage line is EAGLE-I's share of Massachusetts customers tracked each year.
Biggest outages in Middlesex County, 2025
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | December 19, 2025 18:15 | December 21, 2025 13:30 | 1d 19h | 19,321 | 204K |
| 2 | June 23, 2025 14:30 | June 28, 2025 06:30 | 4d 16h | 15,271 | 121K |
| 3 | August 4, 2025 03:15 | August 13, 2025 07:15 | 9d 4h | 12,672 | 60K |
| 4 | July 30, 2025 18:15 | August 2, 2025 05:15 | 2d 11h | 12,391 | 58K |
| 5 | June 13, 2025 23:00 | June 20, 2025 20:45 | 6d 21h | 11,731 | 69K |
| 6 | April 28, 2025 14:15 | May 29, 2025 18:45 | 31d 4h | 9,628 | 108K |
| 7 | July 4, 2025 17:00 | July 19, 2025 16:30 | 14d 23h | 8,681 | 96K |
| 8 | April 12, 2025 17:15 | April 26, 2025 21:45 | 14d 4h | 7,799 | 37K |
| 9 | January 1, 2025 00:00 | January 3, 2025 12:15 | 2d 12h | 7,276 | 32K |
| 10 | August 17, 2025 10:00 | August 23, 2025 06:45 | 5d 20h | 6,058 | 50K |
Outage episodes by size in 2025: 129 reached 100+ customers, 48 reached 1,000+ customers, 5 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Middlesex County reported on EIA Form 861 for 2025, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| Massachusetts Electric Co | 2024 | 2.2 hrs | 1.00 | 1.5 hrs | 0.84 |
| NSTAR Electric Company | 2024 | 81 min | 0.69 | 66 min | 0.64 |
| Unitil Energy Systems | 2024 | 9.9 hrs | 1.73 | 1.6 hrs | 1.00 |
| Fitchburg Gas & Elec Light Co | 2024 | 65 min | 1.05 | 65 min | 1.05 |
| Town of Reading - (MA) | 2024 | 46 min | 0.66 | 23 min | 0.27 |
| Town of Belmont - (MA) | 2018 | 57 min | 0.53 | 57 min | 0.53 |
| Massachusetts Bay Trans Authority | - | - | - | - | - |
| Town of Concord - (MA) | - | - | - | - | - |
| Town of Groton - (MA) | - | - | - | - | - |
| Town of Hudson - (MA) | - | - | - | - | - |
| Town of Littleton - (MA) | - | - | - | - | - |
| Town of Wakefield - (MA) | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about n/a of Massachusetts's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 434,426 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Middlesex County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Middlesex County, MA annual power outage report, 2025, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2025/massachusetts/middlesex-county