Alert archive / Illinois / Mercer County

Weather alerts in Mercer County, Illinois, 2025

143 weather alerts in 2025, 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 2025. Tap one for its archive.

Alerts: 143
Warnings: 43
Watches: 21
Advisories: 45
Busiest month: July34 alerts
Busiest day: July 11, 202513 alerts

Over time

By month

Warning verification

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

5 of 9 tornado warnings covering Mercer County in 2025 had a tornado report inside them; 2 of 4 tornado reports fell inside a warning, on average 13 minutes after it went out.

Mercer County, 2025

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	9	5	44%	4	50%	13 min
Severe thunderstorm warnings	21	14	33%	4	75%	18 min
Flash flood warnings	3	2	33%	1	100%	37 min

Each office's whole area, 2025

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Quad Cities, IA: tornado warnings	36	16	56%	42	62%	15 min
NWS Quad Cities, IA: severe thunderstorm warnings	141	87	38%	309	82%	28 min
NWS Quad Cities, IA: flash flood warnings	41	25	39%	74	88%	106 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 1, 8:37 PM CST	Winter Weather Advisory	DVN	23 hr
Jan 10, 7:31 PM CST	Special Weather Statement	DVN	59 min
Jan 17, 2:39 PM CST	Cold Weather Advisory	DVN	45 hr
Jan 19, 2:54 AM CST	Cold Weather Advisory	DVN	32 hr
Jan 20, 2:42 AM CST	Cold Weather Advisory	DVN	24 hr
Jan 20, 2:42 AM CST	Extreme Cold Warning	DVN	33 hr
Jan 21, 10:23 AM CST	Cold Weather Advisory	DVN	16 hr
Jan 30, 5:42 PM CST	Dense Fog Advisory	DVN	18 hr
Jan 31, 1:40 AM CST	Flood Watch	DVN	13 hr
Feb 4, 1:59 PM CST	Winter Weather Advisory	DVN	37 hr
Feb 10, 2:14 AM CST	Winter Storm Watch	DVN	35 hr
Feb 11, 2:56 AM CST	Winter Storm Warning	DVN	47 hr
Feb 12, 12:23 PM CST	Winter Weather Advisory	DVN	14 hr
Feb 16, 2:36 AM CST	Extreme Cold Watch	DVN	24 hr
Feb 17, 2:38 AM CST	Cold Weather Advisory	DVN	33 hr
Feb 18, 2:26 AM CST	Cold Weather Advisory	DVN	34 hr
Feb 19, 2:22 AM CST	Cold Weather Advisory	DVN	32 hr
Feb 27, 1:18 PM CST	Wind Advisory	DVN	29 hr
Feb 27, 1:50 PM CST	Red Flag Warning	DVN	28 hr
Mar 4, 1:46 AM CST	Wind Advisory	DVN	43 hr
Mar 4, 1:37 PM CST	High Wind Warning	DVN	28 hr
Mar 10, 3:24 AM CDT	Red Flag Warning	DVN	17 hr
Mar 13, 2:56 AM CDT	Wind Advisory	DVN	45 hr
Mar 13, 11:54 AM CDT	Fire Weather Watch	DVN	15 hr
Mar 14, 2:31 AM CDT	Red Flag Warning	DVN	19 hr
Mar 14, 5:01 PM CDT	Mesoscale Discussion	SPC	89 min
Mar 14, 6:55 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Mar 14, 8:06 PM CDT	Mesoscale Discussion	SPC	114 min
Mar 14, 8:18 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	57 min
Mar 14, 8:37 PM CDT	Severe Thunderstorm Warning Destructive damage threat	DVN	38 min
Mar 14, 9:08 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	52 min
Mar 14, 9:21 PM CDT	Mesoscale Discussion	SPC	84 min
Mar 14, 9:26 PM CDT	Severe Thunderstorm Warning Destructive damage threat	DVN	49 min
Mar 17, 2:59 AM CDT	Red Flag Warning	DVN	17 hr
Mar 18, 3:10 PM CDT	Wind Advisory	DVN	37 hr
Mar 19, 4:37 AM CDT	Mesoscale Discussion	SPC	113 min
Mar 19, 11:21 AM CDT	Mesoscale Discussion	SPC	2 hr
Mar 19, 12:16 PM CDT	Tornado Watch	SPC	9 hr
Mar 19, 12:36 PM CDT	Severe Thunderstorm Warning	DVN	54 min
Mar 23, 2:20 AM CDT	Wind Advisory	DVN	22 hr
Mar 28, 2:17 AM CDT	Special Weather Statement	DVN	43 min
Mar 28, 2:58 AM CDT	Severe Thunderstorm Warning	DVN	47 min
Apr 1, 2:04 PM CDT	Wind Advisory	DVN	29 hr
Apr 18, 2:53 PM CDT	Mesoscale Discussion	SPC	3 hr
Apr 20, 2:20 PM CDT	Mesoscale Discussion	SPC	115 min
Apr 20, 3:41 PM CDT	Tornado Watch	SPC	7 hr
Apr 20, 7:14 PM CDT	Severe Thunderstorm Warning	DVN	61 min
Apr 20, 7:25 PM CDT	Severe Thunderstorm Warning	DVN	65 min
Apr 20, 7:33 PM CDT	Tornado Warning	DVN	42 min
Apr 20, 7:46 PM CDT	Mesoscale Discussion	SPC	89 min
Apr 20, 7:55 PM CDT	Severe Thunderstorm Warning	DVN	65 min
Apr 20, 8:00 PM CDT	Tornado Warning	DVN	32 min
Apr 20, 8:36 PM CDT	Tornado Warning	DVN	39 min
May 20, 1:39 PM CDT	Severe Thunderstorm Warning	DVN	66 min
May 20, 1:43 PM CDT	Severe Thunderstorm Warning	DVN	62 min
May 20, 2:03 PM CDT	Tornado Warning	DVN	29 min
Jun 3, 3:39 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 3, 4:41 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 3, 6:14 PM CDT	Mesoscale Discussion	SPC	91 min
Jun 3, 6:23 PM CDT	Severe Thunderstorm Warning	DVN	67 min
Jun 3, 6:29 PM CDT	Tornado Warning	DVN	31 min
Jun 3, 6:46 PM CDT	Tornado Warning	DVN	29 min
Jun 3, 6:47 PM CDT	Tornado Warning	DVN	28 min
Jun 3, 7:07 PM CDT	Tornado Warning Considerable damage threat	DVN	38 min
Jun 3, 7:08 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	52 min
Jun 3, 7:13 PM CDT	Tornado Warning	DVN	47 min
Jun 5, 3:51 AM CDT	Dense Fog Advisory	DVN	4 hr
Jun 8, 3:52 AM CDT	Dense Fog Advisory	DVN	4 hr
Jun 18, 1:58 PM CDT	Extreme Heat Watch	DVN	37 hr
Jun 20, 2:37 AM CDT	Heat Advisory	DVN	4 days
Jun 26, 3:05 AM CDT	Heat Advisory	DVN	16 hr
Jul 10, 6:13 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 10, 7:17 PM CDT	Flood Watch	DVN	30 hr
Jul 10, 10:23 PM CDT	Severe Thunderstorm Warning	DVN	32 min
Jul 11, 12:44 AM CDT	Mesoscale Discussion	SPC	91 min
Jul 11, 1:17 AM CDT	Severe Thunderstorm Watch	SPC	3 hr
Jul 11, 2:43 AM CDT	Mesoscale Discussion	SPC	92 min
Jul 11, 12:18 PM CDT	Mesoscale Discussion	SPC	87 min
Jul 11, 12:54 PM CDT	Tornado Watch	SPC	7 hr
Jul 11, 3:53 PM CDT	Mesoscale Discussion	SPC	97 min
Jul 11, 4:16 PM CDT	Severe Thunderstorm Warning	DVN	59 min
Jul 11, 5:01 PM CDT	Severe Thunderstorm Warning	DVN	44 min
Jul 11, 5:49 PM CDT	Severe Thunderstorm Warning	DVN	56 min
Jul 11, 6:03 PM CDT	Severe Thunderstorm Warning	DVN	57 min
Jul 11, 6:33 PM CDT	Flash Flood Warning	DVN	5 hr
Jul 14, 1:53 AM CDT	Dense Fog Advisory	DVN	8 hr
Jul 18, 12:59 PM CDT	Flood Watch	DVN	47 hr
Jul 19, 7:13 AM CDT	Mesoscale Discussion	SPC	92 min
Jul 20, 4:13 AM CDT	Special Weather Statement	DVN	47 min
Jul 21, 2:47 AM CDT	Extreme Heat Watch	DVN	36 hr
Jul 22, 3:02 AM CDT	Heat Advisory	DVN	16 hr
Jul 22, 2:17 PM CDT	Heat Advisory	DVN	53 hr
Jul 25, 1:20 PM CDT	Flood Watch	DVN	24 hr
Jul 26, 1:45 PM CDT	Heat Advisory	DVN	31 hr
Jul 27, 1:44 PM CDT	Extreme Heat Warning	DVN	30 hr
Jul 28, 10:07 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 29, 3:18 AM CDT	Mesoscale Discussion	SPC	87 min
Jul 29, 3:23 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	55 min
Jul 29, 3:35 AM CDT	Severe Thunderstorm Warning	DVN	55 min
Jul 30, 1:28 AM CDT	Mesoscale Discussion	SPC	2 hr
Jul 30, 2:27 AM CDT	Flood Watch	DVN	11 hr
Jul 30, 4:11 AM CDT	Special Weather Statement	DVN	49 min
Jul 30, 4:35 AM CDT	Special Weather Statement	DVN	40 min
Jul 30, 4:49 AM CDT	Mesoscale Discussion	SPC	56 min
Jul 30, 11:14 AM CDT	River Flood Watch	DVN	7 days
Aug 6, 7:58 PM CDT	Special Weather Statement	DVN	47 min
Aug 6, 8:31 PM CDT	Flash Flood Warning	DVN	107 min
Aug 7, 1:31 PM CDT	Heat Advisory	DVN	29 hr
Aug 8, 2:15 PM CDT	Flood Watch	DVN	53 hr
Aug 9, 2:54 PM CDT	Mesoscale Discussion	SPC	96 min
Aug 10, 4:18 AM CDT	Flash Flood Warning	DVN	5 hr
Aug 15, 11:40 AM CDT	Heat Advisory	DVN	32 hr
Aug 15, 2:16 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 15, 5:52 PM CDT	Mesoscale Discussion	SPC	83 min
Aug 15, 7:04 PM CDT	Special Weather Statement	DVN	41 min
Aug 17, 2:09 AM CDT	Heat Advisory	DVN	18 hr
Aug 18, 3:03 AM CDT	Heat Advisory	DVN	16 hr
Aug 18, 3:51 PM CDT	Mesoscale Discussion	SPC	84 min
Aug 18, 4:55 PM CDT	Special Weather Statement	DVN	35 min
Aug 18, 5:50 PM CDT	Severe Thunderstorm Warning	DVN	70 min
Oct 18, 2:29 AM CDT	Special Weather Statement	DVN	46 min
Oct 22, 1:51 AM CDT	Frost Advisory	DVN	31 hr
Oct 23, 1:59 AM CDT	Freeze Warning	DVN	31 hr
Nov 2, 1:09 AM CST	Dense Fog Advisory	DVN	9 hr
Nov 23, 2:15 PM CST	Dense Fog Advisory	DVN	22 hr
Nov 24, 11:32 PM CST	Dense Fog Advisory	DVN	10 hr
Nov 25, 2:15 AM CST	Wind Advisory	DVN	40 hr
Nov 27, 2:31 AM CST	Winter Storm Watch	DVN	24 hr
Nov 27, 2:09 PM CST	Winter Storm Warning	DVN	60 hr
Nov 29, 10:42 AM CST	Mesoscale Discussion	SPC	5 hr
Nov 30, 1:12 PM CST	Winter Weather Advisory	DVN	35 hr
Dec 5, 1:19 PM CST	Winter Weather Advisory	DVN	41 hr
Dec 9, 1:50 PM CST	Wind Advisory	DVN	19 hr
Dec 11, 1:44 AM CST	Winter Weather Advisory	DVN	22 hr
Dec 12, 3:24 AM CST	Winter Weather Advisory	DVN	39 hr
Dec 12, 1:30 PM CST	Cold Weather Advisory	DVN	65 hr
Dec 13, 9:43 AM CST	Mesoscale Discussion	SPC	4 hr
Dec 18, 2:19 AM CST	Wind Advisory	DVN	22 hr
Dec 18, 9:41 AM CST	Special Weather Statement	DVN	49 min
Dec 24, 7:05 PM CST	Dense Fog Advisory	DVN	9 hr
Dec 25, 9:09 AM CST	Dense Fog Advisory	DVN	24 hr
Dec 26, 7:16 PM CST	Dense Fog Advisory	DVN	41 hr
Dec 27, 1:50 PM CST	Wind Advisory	DVN	44 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	21
Tornado Warning	9
Severe Thunderstorm Watch	5
Tornado Watch	3
Mesoscale Discussion	24
Special Weather Statement	10
Flooding
Flash Flood Warning	3
Flood Watch	6
River Flood Watch	1
Winter
Winter Storm Warning	2
Winter Storm Watch	2
Winter Weather Advisory	7
Heat
Extreme Heat Warning	1
Extreme Heat Watch	2
Heat Advisory	9
Cold
Extreme Cold Warning	1
Freeze Warning	1
Extreme Cold Watch	1
Cold Weather Advisory	8
Frost Advisory	1
Wind and dust
High Wind Warning	1
Wind Advisory	10
Fire
Red Flag Warning	4
Fire Weather Watch	1
Fog and smoke
Dense Fog Advisory	10

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2024 2026

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.