Power Out Map
– 0% of Sheridan out 0 customers out in Montana

Power outage history

Sheridan County Montana

The outage record here is too thin for a reliable yearly average. Raw events are listed below.

Worst outage on record Jul 9, 2018 68% of customers out · 90% back in 23 hours
Hours without power, average customer per year –h / yr State average 4.9 h · national median 6.6 h
Major outages a year – Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 1hours Median across major outages, from the peak
Longest single outage 2.0days Jul 9, 2018, over 1% of customers out
Outage hours on storm days 77% Share falling on days with a NOAA storm report here
Worst year –
Electricity customers 1,766 ORNL customer model · 0 well-covered years

Every day since 2015

Eleven years, one night at a time

Each cell is a day. The brighter it is, the larger the share of Sheridan's customers who were without power at that day's worst moment.

20152016201720182019202020212022202320242025
0%100% of customers out

Year by year

Hours in the dark, per customer

Sheridan, hours without power per customer

SheridanUS median countyMontana average
0 5 10 15 20 25 ’17 ’18 ’19 ’20 ’21 ’22 ’23 ’24 ’25 US 6.6 MT 4.9

The record

The biggest outages since 2015

Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.

Began Storm Peak out Share Lasted 90% restored Customer-hours
Jul 9, 2018 Thunderstorms 1,194 68% 2.0 d 23 h 27k
Jul 23, 2020 Thunderstorms 1,246 71% 12 h 7.0 h 8.3k
Jun 5, 2024 Windstorm 616 35% 7.2 h 3.0 h 3.3k
Jun 20, 2019 No storm report 221 13% 7.0 h 48 min 1.5k
Apr 30, 2018 No storm report 621 35% 3.8 h 12 min 1.3k
Apr 24, 2022 No storm report 290 16% 5.2 h 3.2 h 1.1k
Apr 8, 2021 No storm report 204 12% 5.2 h 5.2 h 1.1k
Jun 10, 2020 No storm report 1,205 68% 48 min 48 min 904
Aug 23, 2019 No storm report 39 2% 29 h – 870
Aug 25, 2019 No storm report 31 2% 26 h – 606
Jan 13, 2021 Windstorm 390 22% 4.0 h 1.5 h 596
Jun 10, 2021 Thunderstorms 174 10% 4.8 h 3.0 h 447

After the peak

How fast the lights come back

Each line is one major outage, from its peak. The amber line is the typical path.

0% 25% 50% 75% 100% peak+24h+48h+72h+96h half back by +2h 90% by +2h

When it happens

The outage clock

Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.

00061218 Jan inside

What was happening

Weather behind the outages

Each outage is matched to NOAA storm reports for Sheridan from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • Thunderstorms 70%
  • No storm on record 23%
  • Windstorm 7.6%

Who keeps the lights on

Utilities serving Sheridan

As each utility reports to the Energy Information Administration for its whole Montana territory, not this county alone. Outage minutes include major storm days.

Utility Type Outage min / yr Excl. major storms Outages / yr Residential ¢/kWh Customers
Sheridan Electric Coop, Inc MT – – – 8.4 39k
Montana-Dakota Utilities Co Investor Owned 146 146 1.23 12.3 20k

EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.

Next door

Neighbouring counties

Across Montana

Where it is darkest

Hours / yr64+

All Montana counties →

About these numbers

Notes

Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 1,766 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →