94:
Over the next four hours, this band of heavy rainfall remained nearly stationary. The band of rainfall dissipated and brief break in heavy rainfall began around 12:00 PM, while a new band of rainfall formed to the north of
Chicago along the shore of Lake Michigan. By 2:00 PM, this second band of heavy rainfall had drifted slowly southward to near Chicago. Over the next three hours, this band of heavy rainfall remained nearly stationary, again impacting some of the same areas as earlier in the morning. The second band of rainfall dissipated around 5:00 PM. In total, widespread rainfall of 2.0 to 9.0 inches (5.1 to 22.9 cm) occurred across the central portion of the Chicago metropolitan area over an 18-hour period, with peak rainfall occurring near the western border of Chicago near Berwyn and Cicero.
65:
86:
31:. Rainfall up to 9.0 inches (23 cm) occurred over an 18-hour period; the majority occurred from early in the morning to late in the afternoon. Flood-related damages across northeastern Illinois were estimated to be at least $ 500 million (equivalent to $ 500 million in 2023) in the Chicago area, making it among the most expensive weather-related events in the history of Chicago and
137:, sending untreated sewage mixed with rain water into the lake. Due to the large number of structures impacted by flooding, the event was declared an Illinois state disaster area on July 11. After a request by the state of Illinois, the event was declared a federal disaster on August 15, which allowed FEMA to offer individual assistance grants to those affected by flooding.
93:
Showers and thunderstorms first began to form in the
Chicago area to the east of an area of low pressure between 5:00 AM and 7:00 AM. Between 7:00 AM and 8:00 AM, a line of heavy rainfall had drifted southward into central Cook County, and was centered near Chicago and the immediate western suburbs.
102:
Widespread flooding of structures and roadways, some significant, occurred across
Chicago and the immediate western suburbs, including the Berwyn, Oak Park, and Cicero areas. Flooding caused at least $ 500 million (equivalent to $ 500 million in 2023) in damages in the Chicago area, making it
72:
During the overnight and early morning hours of July 2, a nearly stationary, weak warm front extended across parts of northern
Illinois from roughly Peoria east-northeast toward the southern Chicago metropolitan area. A weak area of surface low pressure, a remnant
56:, July 2010, July 2011, and September 2022. Primary flood impacts in the Chicago metropolitan area include urban flooding of roadways, underpasses, and basements. During more significant rainfall events, basements may be flooded due to combined sewer backups.
35:. This event was part of a cluster of three extreme rainfall events which occurred in the central portion of the metropolitan area within an approximately one-year period from September 2022 to September 2023. The flood event occurred on the same day as the
103:
one of the most costly weather events in
Chicago history. Flash flooding impacted numerous roadways and underpasses, including multiple Interstate Highways. At least 70,000 basements were flooded. Rainfall exceeded the capacity of the
47:
Prior to July 2023, multiple extreme rainfall events occurred in
Chicago or the nearby suburbs of central Cook County at a frequency of about one to two times per decade. Notable events include flood-producing rainfall in
77:, was located in west-central Illinois, drifting slowly to the northeast. As the area of low pressure neared the Chicago area, showers and thunderstorms developed and continued throughout the day.
305:
290:
271:"President Biden approves Gov. Pritzker's Illinois Disaster Declaration for July 2023 Severe Weather, Unlocking Federal Individual Assistance"
49:
231:
121:
was scheduled to continue with the Grant Park 220 after the Loop 121 the day prior. Heavy rainfall caused a delayed start to the race.
208:
68:
Surface weather features in northeastern
Illinois on July 2, 2023. Maps are valid 3 hours apart and begin at 4:00 AM CDT.
300:
74:
295:
104:
24:
64:
134:
118:
36:
32:
85:
112:
164:
253:"Gov. Pritzker Expands Disaster Proclamation to Additional Counties Following Severe Weather"
270:
252:
194:
284:
130:
108:
53:
89:
Rainfall in the
Chicago Metropolitan Area of northeastern Illinois on July 2, 2023.
232:"The July 2 and September 17, 2023, Flash Flood Events in the Chicago Metro Area"
189:
165:"An Analysis of Extreme Rainfall Events in Chicago and Vicinity Since 1950"
28:
52:, July 1957, June 1967, June 1976, August 1987, July 1996, August 2001,
23:
was caused by a heavy rainfall that occurred on July 2, 2023, in the
84:
63:
111:
to rise above flood stage in and near the
Chicago Loop. The
135:"reverse" the river (back to the original flow direction)
107:, and the resulting combined sewer overflow caused the
172:
National
Weather Service Technical Service Publication
16:
Natural disaster in Chicago, Illinois, United States
37:NASCAR Grant Park 220 on the Chicago Street Course
183:
181:
188:Johnston, Louis; Williamson, Samuel H. (2023).
115:was opened to reduce the effects of flooding.
8:
133:after the Chicago Harbor Lock was opened to
129:Floodwaters from the Chicago River entered
119:NASCAR racing on the Chicago Street Course
239:National Weather Service Technical Paper
146:
306:July 2023 events in the United States
7:
225:
223:
221:
158:
156:
154:
152:
150:
14:
105:deep tunnels and McCook Reservoir
291:2023 floods in the United States
209:Gross Domestic Product deflator
1:
190:"What Was the U.S. GDP Then?"
21:July 2023 Chicago Area Flood
163:Lincoln, W.S. (June 2024).
75:mesoscale convective vortex
322:
25:Chicago Metropolitan Area
230:Lincoln, W.S. (2023).
90:
69:
88:
67:
211:figures follow the
113:Chicago Harbor Lock
301:Floods in Illinois
273:. August 15, 2023.
91:
70:
257:State of Illinois
313:
296:2023 in Illinois
275:
274:
267:
261:
260:
259:. July 24, 2023.
249:
243:
242:
236:
227:
216:
206:
204:
202:
185:
176:
175:
169:
160:
27:of northeastern
321:
320:
316:
315:
314:
312:
311:
310:
281:
280:
279:
278:
269:
268:
264:
251:
250:
246:
234:
229:
228:
219:
200:
198:
187:
186:
179:
167:
162:
161:
148:
143:
127:
100:
83:
62:
60:July 2023 event
45:
17:
12:
11:
5:
319:
317:
309:
308:
303:
298:
293:
283:
282:
277:
276:
262:
244:
217:
213:MeasuringWorth
207:United States
195:MeasuringWorth
177:
145:
144:
142:
139:
126:
123:
99:
96:
82:
79:
61:
58:
54:September 2008
44:
41:
15:
13:
10:
9:
6:
4:
3:
2:
318:
307:
304:
302:
299:
297:
294:
292:
289:
288:
286:
272:
266:
263:
258:
254:
248:
245:
240:
233:
226:
224:
222:
218:
214:
210:
197:
196:
191:
184:
182:
178:
173:
166:
159:
157:
155:
153:
151:
147:
140:
138:
136:
132:
131:Lake Michigan
124:
122:
120:
116:
114:
110:
109:Chicago River
106:
97:
95:
87:
80:
78:
76:
66:
59:
57:
55:
51:
42:
40:
38:
34:
30:
26:
22:
265:
256:
247:
238:
212:
201:November 30,
199:. Retrieved
193:
171:
128:
117:
101:
92:
71:
50:October 1954
46:
20:
18:
33:Cook County
285:Categories
141:References
43:Background
125:Aftermath
215:series.
98:Flooding
81:Rainfall
29:Illinois
235:(PDF)
168:(PDF)
203:2023
19:The
287::
255:.
237:.
220:^
192:.
180:^
170:.
149:^
39:.
241:.
205:.
174:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
