Alert archive / Illinois / LaSalle County

Weather alerts in LaSalle County, Illinois, 2026

208 weather alerts in 2026, 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 2026. Tap one for its archive.

Alerts
208
Warnings
76
Watches
43
Advisories
49
Busiest month
August49 alerts
Busiest day
August 10, 202616 alerts

Over time

By month

Warning verification

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

3 of 10 tornado warnings covering LaSalle County in 2026 had a tornado report inside them; 6 of 7 tornado reports fell inside a warning, on average 29 minutes after it went out.

LaSalle County, 2026

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings10370%786%29 min
Severe thunderstorm warnings341944%2391%23 min
Flash flood warnings8363%10%

Each office's whole area, 2026

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Chicago, IL: tornado warnings752961%9169%19 min
NWS Chicago, IL: severe thunderstorm warnings26516737%1,19490%30 min
NWS Chicago, IL: flash flood warnings593147%18886%119 min

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

The year is still running; reports filed late and damage surveys can still change these figures.

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.

IssuedProductOfficeLasted
Jan 18, 2:13 AM CSTCold Weather AdvisoryLOT34 hr
Jan 21, 3:01 AM CSTExtreme Cold WatchLOT24 hr
Jan 21, 4:42 PM CSTWind AdvisoryLOT7 hr
Jan 22, 3:12 AM CSTCold Weather AdvisoryLOT55 hr
Jan 22, 3:12 AM CSTExtreme Cold WarningLOT33 hr
Jan 24, 1:51 AM CSTWinter Weather AdvisoryLOT42 hr
Jan 25, 2:35 AM CSTCold Weather AdvisoryLOT32 hr
Feb 15, 7:24 AM CSTDense Fog AdvisoryLOT3 hr
Feb 16, 5:20 AM CSTDense Fog AdvisoryLOT4 hr
Feb 17, 1:45 PM CSTFire Weather WatchLOT11 hr
Feb 18, 1:00 AM CSTRed Flag WarningLOT17 hr
Feb 19, 1:56 PM CSTWind AdvisoryLOT26 hr
Feb 27, 5:58 AM CSTDense Fog AdvisoryLOT2 hr
Mar 4, 8:34 PM CSTDense Fog AdvisoryLOT37 hr
Mar 6, 2:10 PM CSTMesoscale DiscussionSPC2 hr
Mar 10, 11:16 AM CDTMesoscale DiscussionSPC29 min
Mar 10, 12:04 PM CDTFlood WatchLOT13 hr
Mar 10, 1:53 PM CDTMesoscale DiscussionSPC3 hr
Mar 10, 3:57 PM CDTTornado WatchSPC10 hr
Mar 10, 4:07 PM CDTSevere Thunderstorm WarningLOT53 min
Mar 10, 4:32 PM CDTSevere Thunderstorm WarningLOT43 min
Mar 10, 7:01 PM CDTSevere Thunderstorm WarningLOT59 min
Mar 10, 7:21 PM CDTMesoscale DiscussionSPC84 min
Mar 10, 7:27 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT43 min
Mar 10, 7:51 PM CDTMesoscale DiscussionSPC54 min
Mar 10, 7:57 PM CDTSevere Thunderstorm WarningLOT63 min
Mar 10, 8:09 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT66 min
Mar 10, 8:10 PM CDTFlash Flood WarningLOT3 hr
Mar 10, 8:36 PM CDTTornado WarningLOT18 min
Mar 10, 11:16 PM CDTAreal Flood AdvisoryLOT119 min
Mar 12, 1:33 AM CDTWind AdvisoryLOT40 hr
Mar 12, 11:28 AM CDTHigh Wind WarningLOT29 hr
Mar 14, 11:57 AM CDTWind AdvisoryLOT30 hr
Mar 15, 9:27 AM CDTWinter Weather AdvisoryLOT39 hr
Mar 26, 2:48 PM CDTMesoscale DiscussionSPC117 min
Mar 26, 4:15 PM CDTSevere Thunderstorm WatchSPC8 hr
Mar 30, 9:21 PM CDTSevere Thunderstorm WatchSPC6 hr
Mar 31, 1:54 AM CDTMesoscale DiscussionSPC96 min
Mar 31, 7:46 AM CDTMesoscale DiscussionSPC89 min
Mar 31, 8:41 AM CDTSevere Thunderstorm WarningLOT49 min
Mar 31, 9:25 AM CDTSevere Thunderstorm WatchSPC6 hr
Apr 2, 1:32 AM CDTWind AdvisoryLOT17 hr
Apr 2, 4:36 AM CDTRiver Flood WatchLOT31 hr
Apr 2, 9:59 AM CDTRiver Flood WatchLOT15 hr
Apr 2, 1:43 PM CDTTornado WatchSPC8 hr
Apr 2, 6:47 PM CDTSevere Thunderstorm WarningLOT43 min
Apr 2, 7:06 PM CDTSevere Thunderstorm WarningLOT24 min
Apr 2, 7:11 PM CDTSevere Thunderstorm WarningLOT34 min
Apr 2, 7:30 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT45 min
Apr 2, 7:43 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT62 min
Apr 3, 12:58 AM CDTRiver Flood WarningLOT45 hr
Apr 3, 11:58 AM CDTRiver Flood WarningLOT7 days
Apr 3, 3:56 PM CDTFlood WatchLOT18 hr
Apr 3, 4:59 PM CDTMesoscale DiscussionSPC2 hr
Apr 3, 10:12 PM CDTRiver Flood WarningLOT4 days
Apr 4, 1:59 AM CDTAreal Flood WarningLOT8 hr
Apr 13, 11:03 AM CDTMesoscale DiscussionSPC87 min
Apr 13, 12:37 PM CDTSevere Thunderstorm WarningLOT24 min
Apr 13, 1:24 PM CDTSevere Thunderstorm WarningLOT51 min
Apr 14, 1:55 PM CDTMesoscale DiscussionSPC2 hr
Apr 14, 7:11 PM CDTFlood WatchLOT30 hr
Apr 14, 10:37 PM CDTRiver Flood WatchLOT21 days
Apr 15, 10:43 AM CDTRiver Flood WatchLOT11 hr
Apr 15, 7:55 PM CDTSevere Thunderstorm WatchSPC4 hr
Apr 15, 9:26 PM CDTMesoscale DiscussionSPC94 min
Apr 17, 11:48 AM CDTFlood WatchLOT15 hr
Apr 17, 12:40 PM CDTTornado WatchSPC9 hr
Apr 17, 1:46 PM CDTRiver Flood WatchLOT16 hr
Apr 17, 1:46 PM CDTRiver Flood WarningLOT6 days
Apr 17, 6:25 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 7:58 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT77 min
Apr 17, 8:07 PM CDTTornado WarningLOT38 min
Apr 17, 8:09 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 8:29 PM CDTTornado WarningLOT46 min
Apr 17, 8:46 PM CDTTornado WarningLOT47 min
Apr 18, 5:44 AM CDTRiver Flood WarningLOT15 hr
Apr 18, 12:41 PM CDTRiver Flood WarningLOT23 hr
Apr 18, 1:29 PM CDTFrost AdvisoryLOT20 hr
Apr 18, 1:29 PM CDTFreeze WatchLOT12 hr
Apr 19, 1:52 AM CDTFreeze WarningLOT30 hr
Apr 26, 8:36 PM CDTRiver Flood WatchLOT38 hr
Apr 27, 11:18 AM CDTWind AdvisoryLOT5 hr
May 1, 3:32 AM CDTFrost AdvisoryLOT28 hr
May 4, 2:59 AM CDTBlowing Dust AdvisoryLOT15 hr
May 4, 3:42 PM CDTMesoscale DiscussionSPC2 hr
May 4, 6:49 PM CDTSevere Thunderstorm WarningLOT41 min
May 4, 7:05 PM CDTAreal Flood AdvisoryLOT3 hr
May 4, 7:13 PM CDTSevere Thunderstorm WarningLOT34 min
May 6, 1:23 PM CDTFrost AdvisoryLOT19 hr
May 12, 9:36 AM CDTBlowing Dust AdvisoryLOT9 hr
May 16, 5:25 AM CDTSevere Thunderstorm WarningLOT50 min
Jun 6, 11:54 PM CDTAreal Flood AdvisoryLOT3 hr
Jun 7, 5:09 PM CDTAreal Flood AdvisoryLOT2 hr
Jun 8, 12:58 PM CDTMesoscale DiscussionSPC92 min
Jun 10, 2:06 PM CDTMesoscale DiscussionSPC54 min
Jun 10, 2:38 PM CDTSevere Thunderstorm WarningLOT48 min
Jun 10, 2:40 PM CDTSevere Thunderstorm WatchSPC4 hr
Jun 10, 6:35 PM CDTMesoscale DiscussionSPC55 min
Jun 10, 6:54 PM CDTFlood WatchLOT7 hr
Jun 10, 7:06 PM CDTTornado WatchSPC4 hr
Jun 10, 7:20 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT70 min
Jun 10, 7:55 PM CDTMesoscale DiscussionSPC95 min
Jun 10, 8:03 PM CDTAreal Flood AdvisoryLOT3 hr
Jun 11, 9:53 AM CDTMesoscale DiscussionSPC97 min
Jun 11, 10:05 AM CDTFlood WatchLOT11 hr
Jun 11, 12:22 PM CDTMesoscale DiscussionSPC83 min
Jun 11, 1:57 PM CDTTornado WatchSPC7 hr
Jun 11, 4:37 PM CDTRiver Flood WarningLOT61 hr
Jun 11, 4:37 PM CDTRiver Flood WarningLOT18 days
Jun 11, 5:12 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT33 min
Jun 11, 5:13 PM CDTMesoscale DiscussionSPC62 min
Jun 11, 5:15 PM CDTTornado Warning Tornado observedConsiderable damage threatLOT60 min
Jun 11, 5:55 PM CDTTornado Warning Tornado observedConsiderable damage threatLOT37 min
Jun 11, 6:14 PM CDTMesoscale DiscussionSPC91 min
Jun 12, 10:39 AM CDTRiver Flood WarningLOT38 hr
Jun 17, 2:20 AM CDTFlood WatchLOT15 hr
Jun 17, 7:49 AM CDTTornado WatchSPC6 hr
Jun 17, 8:16 AM CDTMesoscale DiscussionSPC59 min
Jun 24, 12:44 PM CDTMesoscale DiscussionSPC3 hr
Jun 24, 1:55 PM CDTSevere Thunderstorm WatchSPC8 hr
Jun 24, 6:27 PM CDTSevere Thunderstorm WarningLOT48 min
Jun 24, 6:57 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT63 min
Jun 24, 6:58 PM CDTSevere Thunderstorm WarningLOT52 min
Jun 24, 8:06 PM CDTAreal Flood AdvisoryLOT3 hr
Jun 24, 8:06 PM CDTMesoscale DiscussionSPC84 min
Jun 28, 2:47 AM CDTHeat AdvisoryLOT47 hr
Jun 28, 11:18 AM CDTExtreme Heat WarningLOT5 days
Jul 2, 11:43 PM CDTMesoscale DiscussionSPC2 hr
Jul 3, 11:15 AM CDTMesoscale DiscussionSPC2 hr
Jul 3, 11:52 AM CDTSevere Thunderstorm WatchSPC6 hr
Jul 3, 12:21 PM CDTSevere Thunderstorm WarningLOT54 min
Jul 3, 5:05 PM CDTMesoscale DiscussionSPC115 min
Jul 3, 6:37 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 3, 8:32 PM CDTFlood WatchLOT4 hr
Jul 3, 8:33 PM CDTMesoscale DiscussionSPC117 min
Jul 4, 9:39 AM CDTFlood WatchLOT10 hr
Jul 4, 11:24 AM CDTMesoscale DiscussionSPC3 hr
Jul 4, 12:33 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 4, 1:45 PM CDTSevere Thunderstorm WarningLOT26 min
Jul 4, 2:03 PM CDTFlash Flood WarningLOT3 hr
Jul 4, 2:37 PM CDTAreal Flood AdvisoryLOT3 hr
Jul 4, 5:04 PM CDTAreal Flood WarningLOT2 hr
Jul 4, 5:08 PM CDTRiver Flood WarningLOT4 days
Jul 4, 5:58 PM CDTRiver Flood WarningLOT53 hr
Jul 4, 6:48 PM CDTAreal Flood WarningLOT14 hr
Jul 5, 8:24 AM CDTAreal Flood AdvisoryLOT3 hr
Jul 5, 10:40 AM CDTRiver Flood WarningLOT28 hr
Jul 25, 1:04 PM CDTHeat AdvisoryLOT31 hr
Jul 27, 2:10 AM CDTExtreme Heat WarningLOT19 hr
Jul 27, 3:02 AM CDTDense Fog AdvisoryLOT5 hr
Aug 9, 5:03 PM CDTFlood WatchLOT10 hr
Aug 9, 8:14 PM CDTMesoscale DiscussionSPC2 hr
Aug 9, 8:43 PM CDTSevere Thunderstorm WatchSPC7 hr
Aug 9, 10:16 PM CDTAreal Flood AdvisoryLOT78 min
Aug 9, 10:49 PM CDTAreal Flood AdvisoryLOT45 min
Aug 9, 10:53 PM CDTMesoscale DiscussionSPC2 hr
Aug 9, 11:22 PM CDTTornado WarningLOT23 min
Aug 9, 11:23 PM CDTAreal Flood AdvisoryLOT3 hr
Aug 9, 11:32 PM CDTAreal Flood AdvisoryLOT2 hr
Aug 9, 11:35 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT70 min
Aug 9, 11:36 PM CDTTornado WarningLOT24 min
Aug 9, 11:47 PM CDTFlash Flood WarningLOT3 hr
Aug 9, 11:59 PM CDTTornado Warning Tornado observedLOT17 min
Aug 10, 12:01 AM CDTFlash Flood WarningLOT2 hr
Aug 10, 1:05 AM CDTAreal Flood AdvisoryLOT8 hr
Aug 10, 2:32 AM CDTAreal Flood WarningLOT3 hr
Aug 10, 12:47 PM CDTMesoscale DiscussionSPC2 hr
Aug 11, 7:22 AM CDTSevere Thunderstorm WatchSPC6 hr
Aug 11, 9:00 AM CDTMesoscale DiscussionSPC2 hr
Aug 11, 9:22 AM CDTSevere Thunderstorm Warning Considerable damage threatLOT53 min
Aug 11, 9:32 AM CDTAreal Flood AdvisoryLOT4 hr
Aug 11, 9:48 AM CDTSevere Thunderstorm Warning Considerable damage threatLOT72 min
Aug 11, 8:04 PM CDTMesoscale DiscussionSPC2 hr
Aug 12, 6:41 AM CDTSevere Thunderstorm WatchSPC6 hr
Aug 12, 8:23 AM CDTSevere Thunderstorm WarningLOT66 min
Aug 12, 8:37 AM CDTTornado WarningLOT38 min
Aug 12, 9:04 AM CDTMesoscale DiscussionSPC116 min
Aug 12, 9:06 AM CDTAreal Flood AdvisoryLOT3 hr
Aug 12, 9:37 AM CDTFlash Flood WarningLOT3 hr
Aug 12, 12:17 PM CDTAreal Flood AdvisoryLOT118 min
Aug 13, 2:08 AM CDTFlood WatchLOT32 hr
Aug 13, 2:42 AM CDTDense Fog AdvisoryLOT6 hr
Aug 13, 11:03 PM CDTMesoscale DiscussionSPC117 min
Aug 13, 11:35 PM CDTAreal Flood AdvisoryLOT3 hr
Aug 14, 12:01 PM CDTFlood WatchLOT22 hr
Aug 14, 10:15 PM CDTRiver Flood WarningLOT5 days
Aug 15, 6:39 PM CDTFlood WatchLOT13 hr
Aug 21, 2:22 PM CDTMesoscale DiscussionSPC113 min
Aug 21, 2:57 PM CDTSevere Thunderstorm WatchSPC9 hr
Aug 21, 5:44 PM CDTSevere Thunderstorm WarningLOT46 min
Aug 21, 6:13 PM CDTMesoscale DiscussionSPC2 hr
Aug 21, 6:29 PM CDTSevere Thunderstorm WarningLOT17 min
Aug 21, 7:20 PM CDTSevere Thunderstorm WarningLOT40 min
Aug 21, 7:58 PM CDTAreal Flood AdvisoryLOT4 hr
Aug 21, 8:19 PM CDTFlash Flood WarningLOT4 hr
Aug 21, 9:10 PM CDTSevere Thunderstorm WarningLOT19 min
Aug 21, 11:58 PM CDTAreal Flood AdvisoryLOT6 hr
Aug 31, 12:24 PM CDTHeat AdvisoryLOT33 hr
Aug 31, 12:24 PM CDTHeat AdvisoryLOT3 days
Sep 3, 7:56 PM CDTHeat AdvisoryLOT25 hr
Sep 10, 3:11 AM CDTDense Fog AdvisoryLOT5 hr
Sep 17, 6:49 AM CDTAreal Flood AdvisoryLOT5 hr
Sep 17, 7:07 AM CDTFlash Flood WarningLOT2 hr
Sep 18, 1:47 PM CDTFlood WatchLOT47 hr
Sep 19, 10:10 PM CDTRiver Flood WarningLOT45 hr
Sep 20, 12:16 AM CDTAreal Flood AdvisoryLOT116 min
Sep 20, 2:12 AM CDTFlash Flood WarningLOT5 hr
Sep 20, 10:20 AM CDTRiver Flood WatchLOT25 hr

By product

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

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive2025

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.