Alert archive / Illinois / LaSalle County

Weather alerts in LaSalle County, Illinois, 2024

177 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

LaSalle County and its neighbors

Each county as a circle sized by its count in 2024. Tap one for its archive.

Alerts: 177
Warnings: 46
Watches: 30
Advisories: 44
Busiest month: January33 alerts
Busiest day: July 15, 202413 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

1 of 2 tornado warnings covering LaSalle County in 2024 had a tornado report inside them.

LaSalle County, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	2	1	50%	0
Severe thunderstorm warnings	19	10	47%	15	67%	19 min
Flash flood warnings	0			2	0%

Each office's whole area, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Chicago, IL: tornado warnings	34	20	41%	58	69%	17 min
NWS Chicago, IL: severe thunderstorm warnings	155	88	43%	549	79%	30 min
NWS Chicago, IL: flash flood warnings	22	6	73%	72	72%	85 min

An office's figures cover every county it serves, including across state lines.

Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.

The alerts

Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Jan 8, 3:00 AM CST	Winter Weather Advisory	LOT	47 hr
Jan 8, 2:07 PM CST	Winter Storm Warning	LOT	36 hr
Jan 9, 1:09 PM CST	Mesoscale Discussion	SPC	3 hr
Jan 10, 2:18 PM CST	Winter Storm Watch	LOT	24 hr
Jan 11, 2:22 PM CST	Winter Storm Warning	LOT	37 hr
Jan 11, 2:22 PM CST	Winter Weather Advisory	LOT	46 hr
Jan 12, 4:23 AM CST	Mesoscale Discussion	SPC	4 hr
Jan 12, 9:31 AM CST	Winter Weather Advisory	LOT	26 hr
Jan 13, 3:29 AM CST	Wind Chill Advisory	LOT	4 days
Jan 13, 2:17 PM CST	Wind Chill Warning	LOT	70 hr
Jan 13, 2:17 PM CST	Winter Weather Advisory	LOT	20 hr
Jan 16, 10:01 AM CST	Areal Flood Warning	LOT	4 hr
Jan 16, 1:39 PM CST	River Flood Warning	LOT	21 days
Jan 16, 1:39 PM CST	River Flood Warning	LOT	21 days
Jan 17, 12:14 PM CST	River Flood Advisory	LOT	4 days
Jan 17, 12:14 PM CST	River Flood Advisory	LOT	5 days
Jan 18, 3:41 AM CST	Winter Weather Advisory	LOT	26 hr
Jan 19, 3:28 AM CST	Wind Chill Advisory	LOT	30 hr
Jan 20, 2:44 AM CST	Wind Chill Advisory	LOT	31 hr
Jan 21, 2:42 PM CST	Winter Weather Advisory	LOT	42 hr
Jan 22, 3:21 AM CST	Winter Weather Advisory	LOT	33 hr
Jan 22, 9:17 AM CST	Mesoscale Discussion	SPC	4 hr
Jan 23, 1:57 PM CST	Dense Fog Advisory	LOT	22 hr
Jan 23, 2:04 PM CST	Flood Watch	LOT	4 days
Jan 24, 2:57 PM CST	Dense Fog Advisory	LOT	30 hr
Jan 25, 10:10 AM CST	River Flood Warning	LOT	14 days
Jan 25, 10:16 AM CST	River Flood Warning	LOT	5 days
Jan 26, 7:17 AM CST	River Flood Warning	LOT	50 hr
Jan 26, 12:03 PM CST	River Flood Warning	LOT	72 hr
Jan 26, 1:22 PM CST	Dense Fog Advisory	LOT	33 hr
Jan 27, 11:18 AM CST	River Flood Warning	LOT	46 hr
Jan 28, 10:57 AM CST	River Flood Warning	LOT	34 hr
Jan 29, 5:12 AM CST	Dense Fog Advisory	LOT	6 hr
Feb 6, 1:34 AM CST	Dense Fog Advisory	LOT	10 hr
Feb 6, 9:08 PM CST	Dense Fog Advisory	LOT	12 hr
Feb 8, 2:53 PM CST	Mesoscale Discussion	SPC	3 hr
Feb 8, 4:44 PM CST	Mesoscale Discussion	SPC	61 min
Feb 8, 5:35 PM CST	Special Weather Statement	LOT	25 min
Feb 8, 5:44 PM CST	Special Weather Statement	LOT	31 min
Feb 22, 1:30 AM CST	Special Weather Statement	LOT	45 min
Feb 25, 1:13 PM CST	Fire Weather Watch	LOT	14 hr
Feb 26, 3:05 AM CST	Red Flag Warning	LOT	15 hr
Feb 27, 2:35 PM CST	Wind Advisory	LOT	15 hr
Feb 27, 2:50 PM CST	Mesoscale Discussion	SPC	115 min
Feb 27, 3:53 PM CST	Tornado Watch	SPC	6 hr
Feb 27, 5:54 PM CST	Tornado Warning	LOT	51 min
Feb 27, 5:59 PM CST	Mesoscale Discussion	SPC	91 min
Feb 27, 6:45 PM CST	Severe Thunderstorm Warning	LOT	45 min
Mar 3, 2:13 PM CST	Wind Advisory	LOT	4 hr
Mar 4, 6:39 AM CST	Dense Fog Advisory	LOT	2 hr
Mar 4, 1:25 PM CST	Mesoscale Discussion	SPC	2 hr
Mar 4, 10:26 PM CST	Special Weather Statement	LOT	34 min
Mar 5, 1:38 AM CST	Areal Flood Advisory	LOT	4 hr
Mar 5, 1:49 AM CST	Special Weather Statement	LOT	26 min
Mar 14, 3:15 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Mar 29, 8:52 PM CDT	Mesoscale Discussion	SPC	83 min
Apr 1, 1:24 PM CDT	River Flood Watch	LOT	3 hr
Apr 1, 1:24 PM CDT	River Flood Warning	LOT	13 days
Apr 1, 4:29 PM CDT	River Flood Warning	LOT	21 days
Apr 1, 9:09 PM CDT	River Flood Warning	LOT	39 hr
Apr 1, 9:11 PM CDT	River Flood Watch	LOT	25 hr
Apr 3, 8:10 AM CDT	Wind Advisory	LOT	11 hr
Apr 16, 3:40 PM CDT	Mesoscale Discussion	SPC	95 min
Apr 16, 5:52 PM CDT	Tornado Watch	SPC	4 hr
Apr 20, 2:41 PM CDT	Freeze Warning	LOT	17 hr
Apr 21, 2:29 PM CDT	Frost Advisory	LOT	18 hr
Apr 24, 2:58 PM CDT	Frost Advisory	LOT	17 hr
Apr 26, 3:42 PM CDT	Special Weather Statement	LOT	48 min
Apr 27, 7:58 PM CDT	Mesoscale Discussion	SPC	62 min
Apr 28, 2:01 AM CDT	Areal Flood Advisory	LOT	3 hr
Apr 28, 12:49 PM CDT	River Flood Warning	LOT	8 days
Apr 29, 10:34 AM CDT	River Flood Warning	LOT	34 hr
Apr 29, 11:20 AM CDT	River Flood Warning	LOT	37 hr
May 2, 3:07 PM CDT	Mesoscale Discussion	SPC	113 min
May 2, 6:58 PM CDT	Special Weather Statement	LOT	17 min
May 2, 7:16 PM CDT	Special Weather Statement	LOT	14 min
May 4, 1:56 PM CDT	Mesoscale Discussion	SPC	94 min
May 4, 5:33 PM CDT	Special Weather Statement	LOT	42 min
May 7, 6:40 AM CDT	Special Weather Statement	LOT	50 min
May 7, 12:14 PM CDT	Mesoscale Discussion	SPC	2 hr
May 7, 1:28 PM CDT	Tornado Watch	SPC	12 hr
May 7, 6:51 PM CDT	Severe Thunderstorm Warning	LOT	54 min
May 7, 7:36 PM CDT	Special Weather Statement	LOT	24 min
May 9, 4:08 AM CDT	Special Weather Statement	LOT	37 min
May 9, 4:45 AM CDT	Special Weather Statement	LOT	60 min
May 13, 1:47 PM CDT	Areal Flood Advisory	LOT	43 min
May 13, 2:29 PM CDT	Areal Flood Advisory	LOT	109 min
May 14, 12:15 PM CDT	River Flood Warning	LOT	71 hr
May 17, 2:42 AM CDT	Dense Fog Advisory	LOT	6 hr
May 20, 10:13 AM CDT	Mesoscale Discussion	SPC	92 min
May 21, 7:13 PM CDT	Tornado Watch	SPC	5 hr
May 21, 10:20 PM CDT	Wind Advisory	LOT	6 hr
May 24, 6:07 AM CDT	Severe Thunderstorm Watch	SPC	9 hr
May 24, 8:44 AM CDT	Mesoscale Discussion	SPC	2 hr
May 24, 4:07 PM CDT	Special Weather Statement	LOT	68 min
May 24, 4:46 PM CDT	Mesoscale Discussion	SPC	119 min
May 27, 5:10 PM CDT	Mesoscale Discussion	SPC	2 hr
May 27, 7:21 PM CDT	Severe Thunderstorm Warning	LOT	39 min
May 27, 7:53 PM CDT	Severe Thunderstorm Warning	LOT	37 min
Jun 1, 5:14 PM CDT	Areal Flood Advisory	LOT	3 hr
Jun 5, 1:02 AM CDT	Areal Flood Advisory	LOT	4 hr
Jun 13, 1:02 PM CDT	Mesoscale Discussion	SPC	118 min
Jun 13, 1:50 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 13, 4:46 PM CDT	Mesoscale Discussion	SPC	89 min
Jun 13, 8:13 PM CDT	Severe Thunderstorm Warning	LOT	62 min
Jun 16, 12:33 PM CDT	Mesoscale Discussion	SPC	117 min
Jun 16, 2:15 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 16, 3:42 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 16, 3:58 PM CDT	Severe Thunderstorm Warning	LOT	47 min
Jun 16, 4:39 PM CDT	Dust Storm Advisory	LOT	66 min
Jun 22, 6:55 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 22, 7:36 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 22, 7:37 PM CDT	Flood Watch	LOT	5 hr
Jun 22, 10:43 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 25, 5:00 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 25, 6:28 AM CDT	Mesoscale Discussion	SPC	92 min
Jun 25, 8:29 AM CDT	Special Weather Statement	LOT	31 min
Jun 25, 4:52 PM CDT	Flood Watch	LOT	4 hr
Jun 25, 5:17 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 2, 6:27 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 10, 7:28 PM CDT	Areal Flood Advisory	LOT	3 hr
Jul 13, 3:00 PM CDT	Special Weather Statement	LOT	30 min
Jul 13, 3:28 PM CDT	Special Weather Statement	LOT	32 min
Jul 13, 5:12 PM CDT	Severe Thunderstorm Warning	LOT	33 min
Jul 13, 5:35 PM CDT	Areal Flood Advisory	LOT	3 hr
Jul 13, 5:56 PM CDT	Severe Thunderstorm Warning	LOT	34 min
Jul 13, 6:28 PM CDT	Severe Thunderstorm Warning	LOT	16 min
Jul 14, 7:36 AM CDT	Special Weather Statement	LOT	24 min
Jul 14, 3:03 PM CDT	Flood Watch	LOT	11 hr
Jul 14, 3:15 PM CDT	Mesoscale Discussion	SPC	90 min
Jul 14, 5:55 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 14, 7:51 PM CDT	Mesoscale Discussion	SPC	84 min
Jul 14, 10:52 PM CDT	Mesoscale Discussion	SPC	83 min
Jul 14, 11:10 PM CDT	Severe Thunderstorm Warning	LOT	80 min
Jul 14, 11:35 PM CDT	Severe Thunderstorm Warning	LOT	55 min
Jul 15, 12:05 AM CDT	Tornado Warning	LOT	25 min
Jul 15, 12:28 AM CDT	Severe Thunderstorm Warning	LOT	48 min
Jul 15, 4:07 AM CDT	Heat Advisory	LOT	15 hr
Jul 15, 12:26 PM CDT	River Flood Watch	LOT	4 days
Jul 15, 12:52 PM CDT	Flood Watch	LOT	14 hr
Jul 15, 1:59 PM CDT	Mesoscale Discussion	SPC	3 hr
Jul 15, 5:26 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 15, 6:06 PM CDT	Mesoscale Discussion	SPC	114 min
Jul 15, 6:53 PM CDT	Tornado Watch	SPC	6 hr
Jul 15, 8:21 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	54 min
Jul 15, 8:26 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 15, 8:43 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	62 min
Jul 16, 7:03 AM CDT	River Flood Watch	LOT	14 hr
Jul 23, 6:36 PM CDT	Special Weather Statement	LOT	39 min
Aug 5, 5:09 PM CDT	Mesoscale Discussion	SPC	66 min
Aug 5, 5:52 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Aug 15, 9:08 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 15, 11:47 PM CDT	Severe Thunderstorm Warning	LOT	58 min
Aug 16, 1:19 AM CDT	Mesoscale Discussion	SPC	116 min
Aug 16, 6:40 PM CDT	Severe Thunderstorm Warning	LOT	35 min
Aug 16, 7:08 PM CDT	Severe Thunderstorm Warning	LOT	37 min
Aug 16, 7:35 PM CDT	Special Weather Statement	LOT	25 min
Aug 24, 2:32 PM CDT	Excessive Heat Watch	LOT	48 hr
Aug 25, 3:35 AM CDT	Heat Advisory	LOT	40 hr
Aug 25, 2:13 PM CDT	Excessive Heat Warning	LOT	54 hr
Aug 27, 4:47 PM CDT	Mesoscale Discussion	SPC	88 min
Aug 27, 5:09 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 27, 8:23 PM CDT	Severe Thunderstorm Warning	LOT	37 min
Aug 27, 8:55 PM CDT	Areal Flood Advisory	LOT	3 hr
Aug 27, 9:10 PM CDT	Severe Thunderstorm Warning	LOT	50 min
Aug 27, 9:39 PM CDT	Mesoscale Discussion	SPC	96 min
Oct 14, 1:24 PM CDT	Freeze Watch	LOT	14 hr
Oct 15, 3:29 AM CDT	Freeze Warning	LOT	30 hr
Oct 16, 1:54 PM CDT	Freeze Warning	LOT	19 hr
Oct 28, 1:59 PM CDT	Fire Weather Watch	LOT	13 hr
Oct 29, 2:43 AM CDT	Red Flag Warning	LOT	18 hr
Nov 21, 3:59 AM CST	Wind Advisory	LOT	10 hr
Dec 4, 2:19 AM CST	Wind Advisory	LOT	22 hr
Dec 14, 2:22 AM CST	Winter Weather Advisory	LOT	16 hr
Dec 15, 2:48 AM CST	Dense Fog Advisory	LOT	9 hr
Dec 15, 3:12 PM CST	Dense Fog Advisory	LOT	20 hr
Dec 26, 5:14 AM CST	Dense Fog Advisory	LOT	16 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

Product	Alerts
Severe storms
Severe Thunderstorm Warning	19
Tornado Warning	2
Severe Thunderstorm Watch	11
Tornado Watch	5
Mesoscale Discussion	37
Special Weather Statement	20
Flooding
Areal Flood Warning	1
River Flood Warning	15
Flood Watch	5
River Flood Watch	4
Areal Flood Advisory	9
River Flood Advisory	2
Winter
Winter Storm Warning	2
Winter Storm Watch	1
Winter Weather Advisory	8
Heat
Excessive Heat Warning	1
Excessive Heat Watch	1
Heat Advisory	2
Cold
Freeze Warning	3
Wind Chill Warning	1
Freeze Watch	1
Frost Advisory	2
Wind Chill Advisory	3
Wind and dust
Dust Storm Advisory	1
Wind Advisory	6
Fire
Red Flag Warning	2
Fire Weather Watch	2
Fog and smoke
Dense Fog Advisory	11

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2023 2025

Sources

National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.