Carter County Montana

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

Worst outage on record Apr 16, 2018 7% of customers out · 90% back in 1.0 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% – Median across major outages, from the peak

Longest single outage 1hours Apr 16, 2018, over 1% of customers out

Outage hours on storm days – Share falling on days with a NOAA storm report here

Worst year –

Electricity customers 508 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 Carter'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

Carter, hours without power per customer

CarterUS median countyMontana average

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
Apr 16, 2018	No storm report	33	7%	1.0 h	1.0 h	33

When it happens

The outage clock

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

What was happening

Weather behind the outages

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

No storm on record 100%

Who keeps the lights on

Utilities serving Carter

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
Tongue River Electric Coop Inc	MT	–	–	–	14.1	56k
Southeast Electric Coop, Inc	MT	443	443	–	–	19k
Grand Electric Coop, Inc	SD	–	–	–	11.9	124
Black Hills Power, Inc.	Investor Owned	756	673	3.43	7.0	13

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

Harding, SD 60 h
Crook, WY 18 h
Butte, SD 3.0 h
Custer 0.6 h
Carter (this county) – h

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 508 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 →