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

Power outage history

Madison County Montana

12hours

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

7th most of 35 in Montana 1.8× the national median

Worst outage on record Nov 8, 2020 99% of customers out · 90% back in 11 hours
Hours without power, average customer per year 12h / yr State average 4.9 h · national median 6.6 h
Major outages a year 7.8 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 23hours Aug 25, 2020, over 1% of customers out
Outage hours on storm days 24% Share falling on days with a NOAA storm report here
Worst year 2020 22 hours without power, average customer
Electricity customers 6,199 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 Madison'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 22 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Madison, hours without power per customer

MadisonUS median countyMontana average
0 10 20 30 ’18 ’19 22 ’20 8.9 ’21 9.8 ’22 5.3 ’23 14 ’24 12 ’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
Nov 8, 2020 No storm report 6,110 99% 16 h 11 h 96k
Oct 11, 2021 No storm report 2,860 46% 7.8 h 2.0 h 11k
Jun 28, 2021 No storm report 800 13% 11 h 11 h 8.4k
Dec 17, 2025 Windstorm 1,688 27% 13 h 4.8 h 8.1k
Sep 16, 2025 Wildfire 1,953 32% 3.8 h 3.8 h 7.3k
Feb 7, 2025 Winter storm 1,222 20% 7.5 h 7.5 h 7.1k
Aug 3, 2024 No storm report 768 12% 19 h 14 h 6.6k
Sep 5, 2024 Wildfire 614 10% 11 h 1.0 h 6.6k
May 4, 2024 No storm report 1,213 20% 4.8 h 4.8 h 5.8k
Dec 21, 2022 Winter storm 1,163 19% 8.5 h 9.8 h 5.3k
May 5, 2025 No storm report 882 14% 5.8 h 3.8 h 5.1k
Jul 1, 2023 Thunderstorms 636 10% 9.0 h 4.5 h 5.0k

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 +8h

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

  • No storm on record 76%
  • Winter storm 7.9%
  • Wildfire 7.8%
  • Windstorm 5.0%
  • Thunderstorms 3.6%

Who keeps the lights on

Utilities serving Madison

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

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 6,199 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 →