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

Power outage history

Powell County Montana

6.7hours

without power for the average customer in a typical year, 2018–2025

18th most of 35 in Montana close to the national median

Worst outage on record Jun 8, 2020 43% of customers out · 90% back in 13 hours
Hours without power, average customer per year 6.7h / yr State average 4.9 h · national median 6.6 h
Major outages a year 2.8 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 3hours Median across major outages, from the peak
Longest single outage 5.1days Dec 17, 2025, over 1% of customers out
Outage hours on storm days 61% Share falling on days with a NOAA storm report here
Worst year 2020 14 hours without power, average customer
Electricity customers 4,506 ORNL customer model · 6 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 Powell'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

2020 was the worst well-recorded year, at 14 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Powell, hours without power per customer

PowellUS median countyMontana average
0 5 10 15 20 14 ’20 1.5 ’21 1.4 ’22 1.5 ’23 13 ’24 8.8 ’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
Jun 8, 2020 Winter storm 1,916 43% 2.5 d 13 h 37k
Jul 24, 2024 Heat 2,993 66% 2.7 d 2.2 h 26k
Dec 17, 2025 Windstorm 689 15% 5.1 d 2.2 d 18k
Oct 25, 2020 No storm report 300 7% 2.6 d 2.3 d 10k
Oct 4, 2024 Windstorm 192 4% 28 h – 4.4k
Jun 6, 2020 No storm report 1,982 44% 4.0 h 3.5 h 3.4k
Aug 23, 2024 No storm report 173 4% 26 h – 3.3k
May 23, 2024 Winter storm 411 9% 14 h 9.2 h 3.3k
Sep 9, 2025 No storm report 1,443 32% 2.2 h 9.2 h 3.2k
Jul 4, 2025 No storm report 667 15% 5.0 h 5.0 h 3.0k
Sep 22, 2022 No storm report 439 10% 7.8 h 7.8 h 2.6k
Nov 12, 2020 No storm report 918 20% 2.5 h 2.5 h 2.3k

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 +4h 90% by +6h

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 Powell from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • No storm on record 39%
  • Winter storm 29%
  • Heat 17%
  • Windstorm 15%

Who keeps the lights on

Utilities serving Powell

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
NorthWestern Energy LLC Investor Owned 125 117 1.10 14.4 334k
Missoula Electric Coop, Inc Cooperative 1,332 363 2.40 10.9 15k
Bonneville Power Administration Federal – – – – –

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 4,506 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 →