Alert archive / Illinois / Winnebago County

Weather alerts in Winnebago County, Illinois, 2026

143 weather alerts in 2026, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Winnebago County and its neighbors

Each county as a circle sized by its count in 2026. Tap one for its archive.

Alerts
143
Warnings
44
Watches
34
Advisories
31
Busiest month
April53 alerts
Busiest day
April 15, 202613 alerts

Over time

By month

Warning verification

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

2 of 6 tornado warnings covering Winnebago County in 2026 had a tornado report inside them; 5 of 6 tornado reports fell inside a warning, on average 38 minutes after it went out.

Winnebago County, 2026

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings6267%683%38 min
Severe thunderstorm warnings14936%3244%24 min
Flash flood warnings4175%1100%33 min

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 7, 7:15 AM CSTDense Fog AdvisoryLOT5 hr
Jan 18, 2:13 AM CSTCold Weather AdvisoryLOT34 hr
Jan 20, 4:00 AM CSTWinter Weather AdvisoryLOT23 hr
Jan 21, 3:01 AM CSTExtreme Cold WatchLOT24 hr
Jan 22, 3:12 AM CSTCold Weather AdvisoryLOT55 hr
Jan 22, 3:12 AM CSTExtreme Cold WarningLOT33 hr
Jan 25, 2:35 AM CSTCold Weather AdvisoryLOT32 hr
Feb 17, 1:45 PM CSTFire Weather WatchLOT11 hr
Feb 18, 1:00 AM CSTRed Flag WarningLOT17 hr
Feb 18, 1:02 AM CSTWind AdvisoryLOT17 hr
Feb 19, 1:56 PM CSTWind AdvisoryLOT26 hr
Mar 4, 1:39 AM CSTDense Fog AdvisoryLOT7 hr
Mar 4, 8:34 PM CSTDense Fog AdvisoryLOT37 hr
Mar 10, 2:41 AM CDTDense Fog AdvisoryLOT8 hr
Mar 10, 4:53 PM CDTMesoscale DiscussionSPC97 min
Mar 10, 5:40 PM CDTSevere Thunderstorm WatchSPC7 hr
Mar 10, 7:21 PM CDTMesoscale DiscussionSPC84 min
Mar 10, 7:40 PM CDTSevere Thunderstorm WarningLOT65 min
Mar 12, 1:33 AM CDTWind AdvisoryLOT40 hr
Mar 12, 11:28 AM CDTHigh Wind WarningLOT29 hr
Mar 14, 2:03 AM CDTWinter Storm WatchLOT31 hr
Mar 15, 9:27 AM CDTWinter Storm WarningLOT9 hr
Mar 15, 9:27 AM CDTWinter Weather AdvisoryLOT39 hr
Mar 15, 6:51 PM CDTBlizzard WarningLOT16 hr
Mar 30, 8:57 PM CDTMesoscale DiscussionSPC2 hr
Mar 30, 9:21 PM CDTSevere Thunderstorm WatchSPC6 hr
Mar 30, 11:29 PM CDTMesoscale DiscussionSPC2 hr
Mar 31, 1:54 AM CDTMesoscale DiscussionSPC96 min
Apr 2, 10:25 AM CDTRiver Flood WatchLOT29 hr
Apr 2, 12:28 PM CDTMesoscale DiscussionSPC3 hr
Apr 2, 1:43 PM CDTTornado WatchSPC8 hr
Apr 2, 6:24 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT36 min
Apr 3, 3:01 PM CDTRiver Flood WarningLOT3 days
Apr 3, 3:56 PM CDTFlood WatchLOT18 hr
Apr 4, 2:30 PM CDTRiver Flood WarningLOT23 hr
Apr 14, 12:56 PM CDTMesoscale DiscussionSPC2 hr
Apr 14, 2:33 PM CDTTornado WatchSPC9 hr
Apr 14, 6:36 PM CDTMesoscale DiscussionSPC114 min
Apr 14, 7:11 PM CDTFlood WatchLOT30 hr
Apr 14, 7:59 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT61 min
Apr 14, 8:20 PM CDTTornado WarningLOT25 min
Apr 14, 8:32 PM CDTMesoscale DiscussionSPC88 min
Apr 14, 8:37 PM CDTFlash Flood WarningLOT3 hr
Apr 14, 8:57 PM CDTSevere Thunderstorm Warning Considerable damage threatLOT48 min
Apr 15, 4:23 AM CDTRiver Flood WatchMKX21 days
Apr 15, 11:42 AM CDTRiver Flood WatchLOT20 hr
Apr 15, 11:42 AM CDTRiver Flood WatchLOT23 hr
Apr 15, 11:42 AM CDTRiver Flood WatchLOT24 hr
Apr 15, 11:52 AM CDTRiver Flood WatchLOT24 hr
Apr 15, 11:52 AM CDTRiver Flood WatchLOT20 hr
Apr 15, 4:49 PM CDTMesoscale DiscussionSPC86 min
Apr 15, 7:55 PM CDTSevere Thunderstorm WatchSPC4 hr
Apr 15, 7:56 PM CDTTornado WarningLOT34 min
Apr 15, 8:19 PM CDTSevere Thunderstorm WarningLOT24 min
Apr 15, 8:27 PM CDTFlash Flood WarningLOT4 hr
Apr 15, 10:46 PM CDTRiver Flood WarningMKX44 hr
Apr 15, 11:23 PM CDTRiver Flood WarningMKX5 days
Apr 16, 7:30 AM CDTRiver Flood WarningLOT3 days
Apr 16, 7:58 AM CDTRiver Flood WarningLOT14 days
Apr 16, 11:01 AM CDTRiver Flood WarningLOT13 days
Apr 16, 11:24 AM CDTRiver Flood WarningLOT4 days
Apr 16, 11:29 AM CDTRiver Flood WarningLOT10 days
Apr 16, 12:25 PM CDTRiver Flood WarningMKX21 days
Apr 17, 11:48 AM CDTFlood WatchLOT15 hr
Apr 17, 11:48 AM CDTMesoscale DiscussionSPC2 hr
Apr 17, 12:40 PM CDTTornado WatchSPC9 hr
Apr 17, 4:09 PM CDTTornado WarningLOT66 min
Apr 17, 4:42 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 4:52 PM CDTAreal Flood AdvisoryLOT3 hr
Apr 17, 5:07 PM CDTTornado Warning Tornado observedLOT30 min
Apr 17, 6:25 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 6:39 PM CDTSevere Thunderstorm WarningLOT81 min
Apr 17, 7:09 PM CDTTornado WarningLOT36 min
Apr 17, 7:26 PM CDTFlash Flood WarningLOT4 hr
Apr 17, 10:12 PM CDTRiver Flood WarningMKX24 hr
Apr 17, 10:57 PM CDTRiver Flood WatchLOT36 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 21, 1:07 PM CDTMesoscale DiscussionSPC113 min
Apr 27, 11:18 AM CDTWind AdvisoryLOT5 hr
May 1, 3:32 AM CDTFrost AdvisoryLOT28 hr
May 4, 3:42 PM CDTMesoscale DiscussionSPC2 hr
May 6, 1:23 PM CDTFrost AdvisoryLOT19 hr
May 15, 9:07 PM CDTMesoscale DiscussionSPC113 min
May 15, 10:33 PM CDTSevere Thunderstorm WatchSPC4 hr
May 16, 12:29 AM CDTMesoscale DiscussionSPC91 min
Jun 8, 12:58 PM CDTMesoscale DiscussionSPC92 min
Jun 10, 12:00 PM CDTSevere Thunderstorm WatchSPC9 hr
Jun 10, 1:00 PM CDTMesoscale DiscussionSPC2 hr
Jun 10, 1:38 PM CDTSevere Thunderstorm WarningLOT67 min
Jun 11, 10:05 AM CDTFlood WatchLOT11 hr
Jun 11, 1:57 PM CDTTornado WatchSPC7 hr
Jun 11, 5:30 PM CDTFlash Flood WarningLOT4 hr
Jun 11, 5:39 PM CDTSevere Thunderstorm WarningLOT51 min
Jun 11, 9:06 PM CDTAreal Flood AdvisoryLOT22 hr
Jun 12, 10:57 AM CDTRiver Flood WarningLOT33 hr
Jun 17, 2:20 AM CDTFlood WatchLOT15 hr
Jun 17, 9:17 AM CDTWind AdvisoryLOT5 hr
Jun 24, 12:44 PM CDTMesoscale DiscussionSPC3 hr
Jun 24, 1:55 PM CDTSevere Thunderstorm WatchSPC8 hr
Jun 24, 4:22 PM CDTSevere Thunderstorm WarningLOT38 min
Jun 24, 5:02 PM CDTSevere Thunderstorm WarningLOT43 min
Jun 24, 5:28 PM CDTMesoscale DiscussionSPC92 min
Jun 28, 2:47 AM CDTHeat AdvisoryLOT47 hr
Jun 28, 11:18 AM CDTExtreme Heat WarningLOT5 days
Jul 1, 2:34 PM CDTMesoscale DiscussionSPC116 min
Jul 2, 2:30 PM CDTMesoscale DiscussionSPC90 min
Jul 2, 7:40 PM CDTMesoscale DiscussionSPC2 hr
Jul 3, 11:14 AM CDTSevere Thunderstorm WarningLOT61 min
Jul 3, 11:15 AM CDTMesoscale DiscussionSPC2 hr
Jul 3, 5:05 PM CDTMesoscale DiscussionSPC115 min
Jul 3, 6:35 PM CDTTornado WarningLOT25 min
Jul 3, 6:37 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 3, 6:51 PM CDTSevere Thunderstorm WarningLOT54 min
Jul 4, 12:43 PM CDTAreal Flood AdvisoryLOT3 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 10, 12:47 PM CDTMesoscale DiscussionSPC2 hr
Aug 10, 9:07 PM CDTMesoscale DiscussionSPC113 min
Aug 11, 7:22 AM CDTSevere Thunderstorm WatchSPC6 hr
Aug 11, 8:45 AM CDTSevere Thunderstorm Warning Considerable damage threatLOT90 min
Aug 11, 9:00 AM CDTMesoscale DiscussionSPC2 hr
Aug 11, 9:32 AM CDTAreal Flood AdvisoryLOT4 hr
Aug 11, 8:04 PM CDTMesoscale DiscussionSPC2 hr
Aug 13, 2:42 AM CDTDense Fog AdvisoryLOT6 hr
Aug 18, 5:29 PM CDTMesoscale DiscussionSPC2 hr
Aug 21, 2:22 PM CDTMesoscale DiscussionSPC113 min
Aug 21, 2:57 PM CDTSevere Thunderstorm WatchSPC9 hr
Aug 21, 3:45 PM CDTSevere Thunderstorm WarningLOT22 min
Aug 21, 6:13 PM CDTMesoscale DiscussionSPC2 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 18, 1:47 PM CDTFlood WatchLOT47 hr
Sep 19, 3:29 AM CDTAreal Flood AdvisoryLOT8 hr
Sep 19, 12:27 PM CDTRiver Flood WatchMKX22 hr
Sep 20, 4:30 AM CDTAreal Flood AdvisoryLOT4 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.