massoutage

2021 Illinois Power Outage Report

In 2021, the average Illinois customer went without power for about 2.3 hours — the 41st worst of any US state that year, below the state's decade average. Figures from DOE/ORNL EAGLE-I.

Avg hrs / customer
2.3
Peak customers out
73,829
Rank (worst state)
41st
Counties affected
20

Illinois outages over the decade

Average hours without power per customer, 2021 highlighted.

2.3h20151.5h20161.4h20172.5h20181.8h20195.9h20202.3h20211.6h20224.0h20233.0h20242.5h2025

Hardest-hit Illinois counties in 2021

By peak customers out during the year's worst event.

1Cook County73,8292Lake County42,3793McHenry County30,9594St. Clair County28,4225Kane County23,0546DuPage County19,4977Sangamon County12,4548Jefferson County12,2599Madison County11,76710Logan County11,43811LaSalle County9,82812Lee County9,31013Tazewell County8,61514Marion County8,58215Will County8,35516Winnebago County7,88217Rock Island County7,76418Grundy County7,31019McLean County6,82320Williamson County6,630

Biggest Illinois outages of 2021

CountyBeganPeak customers out
Cook CountyAugust 2, 202173,829
Lake CountyAugust 10, 202142,379
McHenry CountyAugust 10, 202130,959
St. Clair CountyOctober 25, 202128,422
Kane CountyAugust 9, 202123,054
Cook CountyJuly 10, 202122,644
Cook CountyOctober 24, 202120,640
DuPage CountyFebruary 18, 202119,497
Cook CountyDecember 9, 202117,712
Cook CountyAugust 23, 202116,341
Illinois by year:20252024202320222020201920182017
Other states in 2021:LAMIWVTXORMS

Part of the 2021 US Power Outage Report. Source: DOE/ORNL EAGLE-I. “Avg hours per customer” is a SAIDI-like measure (outage customer-minutes ÷ tracked customers); coverage varies by year.