Derechos aren't rare here
A derecho is a long-lived line of storms that does widespread wind damage, including gusts of 75 mph or more along much of its path. NWS Chicago says northern Illinois sees at least 10 of them a decade, roughly one a year, though big ones like August 2026 come less often (NWS Chicago). The NWS also notes that northern Illinois and northern Indiana have long been a corridor of enhanced derecho activity (NWS Chicago). For more on how they form, see the Storm Prediction Center.
Aug. 10, 2020: the Corn Belt derecho
Nationally it was the costliest known thunderstorm event in modern U.S. history, about $11.5 billion. In the NWS Chicago area alone there were more than 160 damaging-wind reports and 15 tornadoes, an August single-day record for the office (NWS Chicago). Around Joliet, the official storm data reads like a tree inventory (NWS Storm Data):
- Northwest Joliet: widespread damage from Caton Farm Road and I-55 southeast through Larkin Avenue and Black Road. Several hundred trees damaged, hundreds of limbs down, some roads blocked, and a few pines with their tops sheared off.
- Jefferson Street and the Cathedral Area: broken limbs in several intersections, power lines down, and at least one car damaged by a large tree. (Our Cathedral Area trees guide covers that neighborhood.)
- Crest Hill: widespread tree damage, worst on the east side, with large limbs and some whole trees blocking roads.
- New Lenox: hundreds of trees uprooted or snapped along Cedar Road and Joliet Highway.
One of the 15 tornadoes ran from the south side of Yorkville to south of Plainfield. NWS says it peaked near 105 mph east of Schlapp Road, did mainly tree damage in neighborhoods south of Renwick Road, and ended just before I-55, with 70 to 80 mph winds carrying on into Crest Hill (NWS Chicago).
Aug. 11, 2026: the second one
This derecho hit the south and southwest suburbs with swaths of 70 to locally 100-plus mph straight-line winds, and spun up 8 confirmed tornadoes in the NWS Chicago area (NWS Chicago). In and around Joliet, the NWS storm reports include (same source):
- Tree damage and minor fascia damage to a house west of the Joliet Mall, and a healthy tree about a foot across snapped at the base on Loch Lane.
- Multiple trees and big limbs down west of Gaylord Road between Division Street and Renwick Road.
- A large limb snapped off near Caterpillar Drive and McDonough Street.
- A 96 mph gust on a private weather station just north-northwest of Shorewood, and an 88 mph gust near Plainfield.
- Tornadoes in Will County: an EF-1 in Wilmington that did substantial tree damage in that town's Oakwood Cemetery, an EF-1 from Mokena to Tinley Park that snapped large hardwoods, and an EF-2 from Monee to Crown Point.
The Herald-News reported large trees damaged at Oakwood Cemetery on Lincoln Highway in Joliet, a tree on a house in unincorporated Lockport Heights, and ComEd showing about 80,000 customers out at 6 p.m. The City of Joliet asked residents to report downed parkway trees or trees blocking a road at 815-724-3650 (Herald-News).
What the record says about your trees
Read the reports and a few patterns show up. These are our observations from the records above, not an engineering study:
- Big limbs fail more than whole trees. Most entries are limbs, 4 to 8 inches and up, not uprooted trunks. A limb over the roof or the service wire is the thing to deal with first.
- Healthy trees break too. The 2026 report from Loch Lane calls out a healthy tree snapped at its base. At 80-plus mph, "it looks fine" isn't a guarantee.
- Old canopies over narrow streets block roads. Jefferson Street and the Cathedral Area in 2020 are the example.
- Wires come down with the trees. Nearly every Joliet entry mentions power lines.
Before the next one
- Parkway tree looks bad? It's the City's. Report it at 815-724-3650 (Joliet Forestry).
- Limbs over the house wire? ComEd will drop or de-energize the service line for free so a contractor can trim. Call 1-800-334-7661 at least 5 days ahead (ComEd). Our ComEd service-drop guide walks through it.
- Dead or hollow tree near the house? Get it looked at in the fall or winter, not the week after a storm, when every crew is booked. See tree removal in Joliet.
- Dead ash? They get brittle. Our EAB timeline for Joliet explains why so many are still standing.
If it's already down, start with storm damage in Joliet.
Sources
Checked Nov. 4, 2026. If a City rule has changed since, the City’s page wins.