Power Out Map
– 0% of Tuolumne out 0 customers out in California

Power outage history

Tuolumne County California

59hours

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

5th most of 56 in California 9.0× the national median

Worst outage on record Oct 27, 2019 100% of customers out · 90% back in 2.6 days
Hours without power, average customer per year 59h / yr State average 6.2 h · national median 6.6 h
Major outages a year 16.1 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 8.4days Jan 27, 2021, over 1% of customers out
Outage hours on storm days 81% Share falling on days with a NOAA storm report here
Worst year 2019 5.0 days without power, average customer
Electricity customers 23,610 ORNL customer model · 8 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 Tuolumne'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

2019 was the worst well-recorded year, at 5.0 days for the average customer. Hatched years have a thin record and are left out of the averages.

Tuolumne, hours without power per customer

TuolumneUS median countyCalifornia average
0 50 100 150 ’16 ’17 2.9 ’18 120 ’19 89 ’20 111 ’21 22 ’22 85 ’23 28 ’24 14 ’25 US 6.6 CA 6.2

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
Oct 27, 2019 Wildfire 23,610 100% 3.6 d 2.6 d 1.2M
Sep 7, 2020 Wildfire 23,610 100% 41 h 39 h 774k
Oct 25, 2020 Windstorm 23,610 100% 45 h 43 h 648k
Dec 25, 2021 Winter storm 9,277 39% 4.8 d 4.7 d 610k
Jan 27, 2021 Winter storm 6,211 26% 8.4 d 4.5 d 575k
Feb 27, 2023 Winter storm 10,969 46% 7.2 d 4.1 d 551k
Sep 9, 2023 Wildfire 23,610 100% 2.1 d 26 h 536k
Oct 10, 2019 Wildfire 23,610 100% 45 h 32 h 515k
Feb 5, 2019 Winter storm 23,610 100% 3.1 d 39 h 485k
Jan 19, 2021 Windstorm 7,690 33% 3.7 d 3.2 d 362k
Aug 20, 2020 Wildfire 4,154 18% 3.8 d 23 h 279k
Oct 9, 2019 No storm report 23,610 100% 11 h 23 h 242k

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 +28h 90% by +44h

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

  • Wildfire 36%
  • Winter storm 32%
  • No storm on record 19%
  • Windstorm 10%
  • Heat 2.5%

Who keeps the lights on

Utilities serving Tuolumne

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

Utility Type Outage min / yr Excl. major storms Outages / yr Residential ¢/kWh Customers
Pacific Gas & Electric Co. Investor Owned 273 208 1.63 37.5 5.1M
Southern California Edison Co Investor Owned 545 116 1.39 31.5 4.6M
Turlock Irrigation District Political Subdivision 62 62 0.66 17.4 81k
WAPA-- Western Area Power Administration Federal – – – – –
Tuolumne County Pub Power Agny CA – – – – –

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 California

Where it is darkest

Hours / yr64+

All California 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 23,610 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 →