County annual report · FIPS 30091
2018 Sheridan County, MT Power Outage Report
In 2018, customers in Sheridan County, MT went without power for an average of 19.1 hours, a total of 34K customer-hours (Montana average 1.9 hours). That ranks 1st worst of 20 Montana counties and 295th of 2,798 nationally.
Compared with MT, the US and 2017
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Sheridan County, 2018
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | July 10, 2018 01:00 | July 18, 2018 23:15 | 8d 22h | 1,194 | 29K |
| 2 | April 30, 2018 10:15 | April 30, 2018 14:15 | 4h | 621 | 1,283 |
| 3 | June 23, 2018 22:30 | June 24, 2018 00:00 | 1h 30m | 295 | 357 |
| 4 | May 24, 2018 21:00 | May 24, 2018 23:15 | 2h 15m | 247 | 96 |
| 5 | June 22, 2018 08:15 | June 22, 2018 09:30 | 1h 15m | 146 | 180 |
| 6 | April 11, 2018 06:15 | April 11, 2018 07:15 | 1h | 31 | 31 |
| 7 | May 24, 2018 18:45 | May 24, 2018 19:30 | 45m | 30 | 23 |
| 8 | April 30, 2018 17:15 | April 30, 2018 17:45 | 30m | 17 | 7 |
| 9 | July 19, 2018 00:15 | July 20, 2018 01:15 | 1d 1h | 11 | 226 |
| 10 | August 23, 2018 02:15 | August 31, 2018 15:00 | 8d 12h | 10 | 2,047 |
Outage episodes by size in 2018: 5 reached 100+ customers, 1 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 Sheridan County reported on EIA Form 861 for 2018, 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 |
|---|---|---|---|---|---|
| Montana-Dakota Utilities Co | - | - | - | - | - |
| Sheridan Electric Coop, Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 16% of Montana's customers in 2018; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 1,766 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. Sheridan County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Sheridan County, MT annual power outage report, 2018, 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/). https://massoutage.com/reports/2018/montana/sheridan-county