Alert archive / Illinois / Mercer County
Weather alerts in Mercer County, Illinois, 2026
167 weather alerts in 2026, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Mercer County and its neighbors
Each county as a circle sized by its count in 2026. Tap one for its archive.
- Alerts
- 167
- Warnings
- 56
- Watches
- 41
- Advisories
- 20
- Busiest month
- August31 alerts
- Busiest day
- March 31, 20269 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 4 tornado warnings covering Mercer County in 2026 had a tornado report inside them; 0 of 1 tornado reports fell inside a warning.
Mercer County, 2026
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 0 | 100% | 1 | 0% | |
| Severe thunderstorm warnings | 30 | 18 | 40% | 4 | 75% | 45 min |
| Flash flood warnings | 7 | 4 | 43% | 2 | 100% | 131 min |
Each office's whole area, 2026
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Quad Cities, IA: tornado warnings | 93 | 25 | 73% | 49 | 65% | 22 min |
| NWS Quad Cities, IA: severe thunderstorm warnings | 290 | 168 | 42% | 599 | 80% | 25 min |
| NWS Quad Cities, IA: flash flood warnings | 50 | 33 | 34% | 61 | 89% | 103 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 6, 11:58 PM CST | Dense Fog Advisory | DVN | 12 hr |
| Jan 17, 1:51 PM CST | Cold Weather Advisory | DVN | 46 hr |
| Jan 21, 2:46 AM CST | Extreme Cold Watch | DVN | 31 hr |
| Jan 21, 2:46 AM CST | Wind Advisory | DVN | 21 hr |
| Jan 22, 2:38 AM CST | Extreme Cold Warning | DVN | 33 hr |
| Jan 22, 10:02 AM CST | Cold Weather Advisory | DVN | 50 hr |
| Jan 25, 1:48 AM CST | Cold Weather Advisory | DVN | 34 hr |
| Feb 15, 7:30 AM CST | Dense Fog Advisory | DVN | 3 hr |
| Feb 17, 2:31 PM CST | Fire Weather Watch | DVN | 10 hr |
| Feb 18, 12:30 AM CST | Red Flag Warning | DVN | 18 hr |
| Feb 19, 7:11 PM CST | Wind Advisory | DVN | 15 hr |
| Feb 20, 1:30 AM CST | Wind Advisory | DVN | 9 hr |
| Feb 26, 1:46 PM CST | Fire Weather Watch | DVN | 12 hr |
| Feb 27, 1:35 AM CST | Red Flag Warning | DVN | 16 hr |
| Mar 4, 8:40 PM CST | Dense Fog Advisory | DVN | 12 hr |
| Mar 6, 11:48 PM CST | Special Weather Statement | DVN | 57 min |
| Mar 10, 1:53 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 10, 3:57 PM CDT | Tornado Watch | SPC | 10 hr |
| Mar 10, 5:54 PM CDT | Severe Thunderstorm Warning | DVN | 51 min |
| Mar 10, 6:22 PM CDT | Severe Thunderstorm Warning | DVN | 38 min |
| Mar 10, 6:45 PM CDT | Severe Thunderstorm Warning | DVN | 44 min |
| Mar 10, 7:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Mar 10, 7:49 PM CDT | Severe Thunderstorm Warning | DVN | 56 min |
| Mar 10, 7:51 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Mar 10, 8:43 PM CDT | Severe Thunderstorm Warning | DVN | 43 min |
| Mar 12, 2:34 AM CDT | Wind Advisory | DVN | 33 hr |
| Mar 12, 10:37 AM CDT | High Wind Warning | DVN | 28 hr |
| Mar 13, 2:55 AM CDT | Winter Storm Watch | DVN | 56 hr |
| Mar 14, 12:33 PM CDT | Blizzard Warning | DVN | 48 hr |
| Mar 14, 12:33 PM CDT | High Wind Warning | DVN | 41 hr |
| Mar 16, 1:05 PM CDT | Winter Weather Advisory | DVN | 11 hr |
| Mar 26, 4:15 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Mar 26, 8:32 PM CDT | Special Weather Statement | DVN | 43 min |
| Mar 27, 11:59 AM CDT | Red Flag Warning | DVN | 33 hr |
| Mar 30, 9:21 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Mar 31, 1:54 AM CDT | Mesoscale Discussion | SPC | 96 min |
| Mar 31, 7:13 AM CDT | Special Weather Statement | DVN | 47 min |
| Mar 31, 7:18 AM CDT | Severe Thunderstorm Warning | DVN | 42 min |
| Mar 31, 7:46 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Mar 31, 8:11 AM CDT | Severe Thunderstorm Warning | DVN | 49 min |
| Mar 31, 9:34 AM CDT | Severe Thunderstorm Warning | DVN | 30 min |
| Mar 31, 10:23 AM CDT | Severe Thunderstorm Warning | DVN | 29 min |
| Mar 31, 10:27 AM CDT | Severe Thunderstorm Warning | DVN | 26 min |
| Apr 2, 2:50 AM CDT | Wind Advisory | DVN | 16 hr |
| Apr 2, 12:28 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 2, 1:43 PM CDT | Tornado Watch | SPC | 8 hr |
| Apr 2, 3:41 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Apr 2, 4:26 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Apr 2, 4:28 PM CDT | Severe Thunderstorm Warning | DVN | 62 min |
| Apr 13, 11:03 AM CDT | Mesoscale Discussion | SPC | 87 min |
| Apr 14, 2:33 PM CDT | Tornado Watch | SPC | 9 hr |
| Apr 14, 7:08 PM CDT | Severe Thunderstorm Warning | DVN | 38 min |
| Apr 14, 11:38 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Apr 15, 1:47 AM CDT | Mesoscale Discussion | SPC | 88 min |
| Apr 15, 11:21 AM CDT | River Flood Watch | DVN | 21 days |
| Apr 15, 11:21 AM CDT | River Flood Watch | DVN | 21 days |
| Apr 15, 3:40 PM CDT | Tornado Watch | SPC | 6 hr |
| Apr 15, 6:15 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 15, 7:51 PM CDT | Severe Thunderstorm Warning | DVN | 54 min |
| Apr 15, 8:02 PM CDT | Tornado Warning | DVN | 28 min |
| Apr 15, 8:24 PM CDT | Tornado Warning | DVN | 39 min |
| Apr 15, 9:26 PM CDT | River Flood Watch | DVN | 21 days |
| Apr 16, 11:30 AM CDT | River Flood Warning | DVN | 21 days |
| Apr 16, 11:30 AM CDT | River Flood Warning | DVN | 21 days |
| Apr 16, 11:30 AM CDT | River Flood Warning | DVN | 12 days |
| Apr 17, 12:40 PM CDT | Tornado Watch | SPC | 9 hr |
| Apr 17, 12:46 PM CDT | Flood Watch | DVN | 12 hr |
| Apr 17, 5:46 PM CDT | Tornado Warning | DVN | 24 min |
| Apr 17, 5:51 PM CDT | Severe Thunderstorm Warning | DVN | 54 min |
| Apr 17, 6:00 PM CDT | Severe Thunderstorm Warning | DVN | 60 min |
| Apr 17, 6:25 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 17, 6:43 PM CDT | Severe Thunderstorm Warning | DVN | 62 min |
| Apr 19, 2:10 AM CDT | Freeze Warning | DVN | 30 hr |
| May 1, 2:16 AM CDT | Frost Advisory | DVN | 30 hr |
| May 4, 3:42 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 4, 4:46 PM CDT | Special Weather Statement | DVN | 44 min |
| May 4, 5:33 PM CDT | Severe Thunderstorm Warning | DVN | 42 min |
| May 4, 5:42 PM CDT | Severe Thunderstorm Warning | DVN | 48 min |
| May 4, 6:10 PM CDT | Severe Thunderstorm Warning | DVN | 50 min |
| May 16, 3:49 AM CDT | Special Weather Statement | DVN | 41 min |
| Jun 7, 11:46 AM CDT | Flood Watch | DVN | 31 hr |
| Jun 8, 12:58 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jun 9, 2:00 AM CDT | Heat Advisory | DVN | 18 hr |
| Jun 10, 10:58 AM CDT | Flood Watch | DVN | 32 hr |
| Jun 10, 11:09 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 10, 11:26 AM CDT | Severe Thunderstorm Warning | DVN | 64 min |
| Jun 10, 12:00 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 10, 4:01 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 10, 5:53 PM CDT | Severe Thunderstorm Warning | DVN | 52 min |
| Jun 11, 7:31 AM CDT | Tornado Watch | SPC | 7 hr |
| Jun 11, 9:18 AM CDT | Severe Thunderstorm Warning | DVN | 52 min |
| Jun 11, 9:20 AM CDT | Severe Thunderstorm Warning | DVN | 54 min |
| Jun 11, 9:53 AM CDT | Mesoscale Discussion | SPC | 97 min |
| Jun 11, 1:57 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 11, 3:07 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Jun 16, 1:36 PM CDT | Flood Watch | DVN | 29 hr |
| Jun 17, 3:55 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 17, 5:42 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 17, 7:35 AM CDT | Severe Thunderstorm Warning | DVN | 55 min |
| Jun 17, 7:55 AM CDT | Flash Flood Warning | DVN | 5 hr |
| Jun 17, 7:57 AM CDT | Severe Thunderstorm Warning | DVN | 63 min |
| Jun 17, 8:16 AM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 17, 8:25 AM CDT | Severe Thunderstorm Warning | DVN | 65 min |
| Jun 17, 8:45 AM CDT | Flash Flood Warning | DVN | 4 hr |
| Jun 27, 1:28 AM CDT | Extreme Heat Watch | DVN | 24 hr |
| Jun 27, 1:24 PM CDT | Extreme Heat Warning | DVN | 6 days |
| Jul 1, 2:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 2, 12:37 PM CDT | Flood Watch | DVN | 55 hr |
| Jul 2, 10:59 PM CDT | Special Weather Statement | DVN | 61 min |
| Jul 2, 11:43 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 3, 11:15 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 3, 5:05 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 3, 6:37 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 3, 8:33 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jul 17, 12:32 PM CDT | Heat Advisory | DVN | 30 hr |
| Jul 20, 11:36 AM CDT | Mesoscale Discussion | SPC | 114 min |
| Jul 20, 11:43 AM CDT | Special Weather Statement | DVN | 47 min |
| Jul 20, 11:52 AM CDT | Severe Thunderstorm Warning | DVN | 53 min |
| Jul 20, 12:36 PM CDT | Tornado Warning | DVN | 39 min |
| Jul 20, 5:37 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Jul 20, 5:38 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 24, 1:38 AM CDT | Extreme Heat Watch | DVN | 59 hr |
| Jul 25, 2:49 AM CDT | Extreme Heat Warning | DVN | 67 hr |
| Jul 31, 6:31 PM CDT | Special Weather Statement | DVN | 59 min |
| Aug 5, 2:03 AM CDT | Flood Watch | DVN | 16 hr |
| Aug 9, 1:41 AM CDT | Heat Advisory | DVN | 18 hr |
| Aug 9, 8:14 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 9, 8:43 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 9, 10:53 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 10, 1:57 PM CDT | Heat Advisory | DVN | 30 hr |
| Aug 11, 7:22 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 11, 9:00 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 12, 6:41 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 12, 7:49 AM CDT | Severe Thunderstorm Warning | DVN | 41 min |
| Aug 12, 10:57 AM CDT | Special Weather Statement | DVN | 33 min |
| Aug 12, 11:24 AM CDT | Special Weather Statement | DVN | 36 min |
| Aug 13, 2:22 AM CDT | Flood Watch | DVN | 56 hr |
| Aug 13, 2:35 AM CDT | Dense Fog Advisory | DVN | 6 hr |
| Aug 13, 5:47 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 13, 10:28 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 13, 10:35 AM CDT | Special Weather Statement | DVN | 55 min |
| Aug 13, 11:13 AM CDT | Special Weather Statement | DVN | 47 min |
| Aug 13, 11:03 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Aug 14, 4:59 AM CDT | Flash Flood Warning | DVN | 6 hr |
| Aug 15, 8:43 PM CDT | Special Weather Statement | DVN | 47 min |
| Aug 15, 9:23 PM CDT | Flash Flood Warning | DVN | 6 hr |
| Aug 15, 9:50 PM CDT | Severe Thunderstorm Warning | DVN | 55 min |
| Aug 19, 2:38 PM CDT | Special Weather Statement | DVN | 52 min |
| Aug 19, 5:36 PM CDT | Special Weather Statement | DVN | 39 min |
| Aug 19, 6:06 PM CDT | Flash Flood Warning | DVN | 2 hr |
| Aug 19, 6:36 PM CDT | Flash Flood Warning | DVN | 113 min |
| Aug 21, 2:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Aug 21, 2:57 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 21, 8:54 PM CDT | Special Weather Statement | DVN | 66 min |
| Aug 30, 1:04 PM CDT | Heat Advisory | DVN | 6 days |
| Sep 2, 2:02 AM CDT | Extreme Heat Warning | DVN | 4 days |
| Sep 8, 7:33 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Sep 11, 2:07 AM CDT | Dense Fog Advisory | DVN | 8 hr |
| Sep 16, 12:32 PM CDT | Flood Watch | DVN | 20 hr |
| Sep 18, 1:23 AM CDT | Flood Watch | DVN | 60 hr |
| Sep 19, 10:12 PM CDT | River Flood Watch | DVN | 5 days |
| Sep 19, 10:12 PM CDT | River Flood Watch | DVN | 6 days |
| Sep 19, 10:12 PM CDT | River Flood Watch | DVN | 6 days |
| Sep 19, 11:56 PM CDT | Special Weather Statement | DVN | 64 min |
| Sep 20, 1:18 AM CDT | Severe Thunderstorm Warning | DVN | 57 min |
| Sep 20, 1:38 AM CDT | Flash Flood Warning | DVN | 6 hr |
| Sep 21, 11:47 AM CDT | River Flood Warning | DVN | 47 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.