Power Out Map
– 0% of Lewis and Clark out 0 customers out in Montana

Power outage history

Lewis and Clark County Montana

4.4hours

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

24th most of 35 in Montana 33% below the national median

Worst outage on record Dec 17, 2025 30% of customers out · 90% back in 31 hours
Hours without power, average customer per year 4.4h / yr State average 4.9 h · national median 6.6 h
Major outages a year 2.3 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 2.4days Dec 17, 2025, over 1% of customers out
Outage hours on storm days 45% Share falling on days with a NOAA storm report here
Worst year 2025 8.4 hours without power, average customer
Electricity customers 32,887 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 Lewis and Clark'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

2025 was the worst well-recorded year, at 8.4 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Lewis and Clark, hours without power per customer

Lewis and ClarkUS median countyMontana average
0 2 4 6 8 10 ’19 4.0 ’20 5.1 ’21 2.9 ’22 2.3 ’23 3.6 ’24 8.4 ’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
Dec 17, 2025 Windstorm 9,800 30% 2.4 d 31 h 146k
Jan 13, 2021 No storm report 3,470 11% 32 h 19 h 38k
Jun 3, 2025 No storm report 12,309 37% 2.8 h 1.5 h 27k
May 6, 2024 Windstorm 3,211 10% 7.5 h 16 h 24k
Nov 5, 2022 Windstorm 2,780 8% 13 h 7.5 h 22k
Apr 1, 2025 Winter storm 1,958 6% 16 h 15 h 16k
May 8, 2024 Winter storm 1,412 4% 19 h – 15k
Apr 5, 2021 No storm report 5,516 17% 7.8 h 2.8 h 14k
Aug 22, 2022 No storm report 1,820 6% 7.5 h 7.5 h 12k
Jun 3, 2020 No storm report 8,404 26% 2.2 h 48 min 12k
Aug 3, 2025 No storm report 2,687 8% 7.5 h 2.8 h 12k
Jul 19, 2021 No storm report 5,593 17% 2.0 h 4.8 h 11k

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 +4h

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

  • No storm on record 56%
  • Windstorm 32%
  • Winter storm 7.6%
  • Wildfire 1.8%
  • Thunderstorms 1.8%
  • Flooding 1.5%

Who keeps the lights on

Utilities serving Lewis and Clark

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
Vigilante Electric Coop, Inc MT – – – 8.6 119k
Sun River Electric Coop, Inc MT 79 79 – 13.3 47k
WAPA-- Western Area 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 32,887 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 →