County annual report · FIPS 36059
2021 Nassau County, NY Power Outage Report
In 2021, customers in Nassau County, NY went without power for an average of 1.3 hours, a total of 575K customer-hours (New York average 2.7 hours). That ranks 56th worst of 62 New York counties and 2529th of 2,974 nationally.
Compared with NY, the US and 2020
Coverage line is EAGLE-I's share of New York customers tracked each year.
Biggest outages in Nassau County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | March 25, 2021 11:30 | March 26, 2021 08:00 | 20h 30m | 6,525 | 6,400 |
| 2 | July 8, 2021 11:30 | July 13, 2021 11:00 | 4d 23h | 6,463 | 52K |
| 3 | November 12, 2021 12:45 | November 16, 2021 02:30 | 3d 13h | 6,180 | 36K |
| 4 | August 31, 2021 11:00 | September 5, 2021 04:15 | 4d 17h | 5,643 | 58K |
| 5 | July 6, 2021 10:15 | July 8, 2021 09:15 | 1d 23h | 4,323 | 24K |
| 6 | March 4, 2021 13:15 | March 5, 2021 07:45 | 18h 30m | 3,389 | 5,179 |
| 7 | August 25, 2021 11:15 | August 29, 2021 07:45 | 3d 20h | 3,264 | 6,139 |
| 8 | March 26, 2021 12:30 | March 28, 2021 04:30 | 1d 16h | 3,217 | 9,112 |
| 9 | September 13, 2021 11:15 | September 16, 2021 06:45 | 2d 19h | 2,962 | 6,095 |
| 10 | March 14, 2021 12:30 | March 16, 2021 03:00 | 1d 14h | 2,931 | 5,209 |
Outage episodes by size in 2021: 255 reached 100+ customers, 55 reached 1,000+ customers, 0 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 Nassau County reported on EIA Form 861 for 2021, 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 |
|---|---|---|---|---|---|
| Village of Freeport - (NY) | 2021 | 34 min | 1.31 | 19 min | 1.20 |
| Long Island Power Authority | - | - | - | - | - |
| Village of Rockville Centre - (NY) | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 99% of New York's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 427,483 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. Nassau County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Nassau County, NY annual power outage report, 2021, 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/2021/new-york/nassau-county