Weather alerts in Sioux County, Iowa, 2024

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

Sioux County and its neighbors

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

Alerts: 163
Warnings: 63
Watches: 27
Advisories: 46
Busiest month: June41 alerts
Busiest day: June 21, 202416 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 9 tornado warnings covering Sioux County in 2024 had a tornado report inside them; 4 of 5 tornado reports fell inside a warning, on average 8 minutes after it went out.

Sioux County, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	9	3	67%	5	80%	8 min
Severe thunderstorm warnings	10	8	20%	7	43%	10 min
Flash flood warnings	8	8	0%	5	100%	69 min

Each office's whole area, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Sioux Falls, SD: tornado warnings	27	4	85%	12	50%	9 min
NWS Sioux Falls, SD: severe thunderstorm warnings	147	91	38%	246	76%	19 min
NWS Sioux Falls, SD: flash flood warnings	34	29	15%	54	89%	90 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 2, 5:51 PM CST	Dense Fog Advisory	FSD	18 hr
Jan 6, 3:09 AM CST	Winter Storm Watch	FSD	35 hr
Jan 7, 2:58 AM CST	Winter Storm Warning	FSD	63 hr
Jan 10, 3:12 PM CST	Winter Storm Watch	FSD	12 hr
Jan 10, 3:12 PM CST	Winter Storm Warning	FSD	51 hr
Jan 11, 2:45 PM CST	Blizzard Warning	FSD	57 hr
Jan 11, 2:45 PM CST	Wind Chill Warning	FSD	5 days
Jan 15, 2:18 AM CST	Wind Chill Advisory	FSD	34 hr
Jan 17, 2:09 PM CST	Winter Weather Advisory	FSD	36 hr
Jan 19, 2:26 AM CST	Wind Chill Advisory	FSD	32 hr
Jan 22, 2:34 PM CST	Dense Fog Advisory	FSD	21 hr
Jan 23, 6:09 PM CST	Dense Fog Advisory	FSD	16 hr
Jan 24, 5:41 PM CST	Dense Fog Advisory	FSD	18 hr
Jan 25, 2:21 PM CST	Dense Fog Advisory	FSD	22 hr
Jan 26, 12:01 PM CST	Dense Fog Advisory	FSD	24 hr
Jan 27, 2:15 PM CST	Dense Fog Advisory	FSD	19 hr
Feb 1, 2:38 AM CST	Dense Fog Advisory	FSD	11 hr
Feb 2, 2:38 AM CST	Dense Fog Advisory	FSD	4 days
Feb 4, 1:50 PM CST	Dense Fog Advisory	FSD	25 hr
Feb 14, 1:53 PM CST	Winter Weather Advisory	FSD	37 hr
Feb 26, 2:01 PM CST	Wind Advisory	FSD	31 hr
Feb 27, 3:53 PM CST	Mesoscale Discussion	SPC	3 hr
Feb 28, 2:00 PM CST	Fire Weather Watch	FSD	12 hr
Feb 29, 1:46 AM CST	Red Flag Warning	FSD	17 hr
Mar 6, 3:24 AM CST	Red Flag Warning	FSD	15 hr
Mar 10, 3:35 AM CDT	Fire Weather Watch	FSD	23 hr
Mar 11, 2:37 AM CDT	Red Flag Warning	FSD	16 hr
Mar 16, 3:04 AM CDT	Red Flag Warning	FSD	17 hr
Mar 25, 3:23 AM CDT	Winter Weather Advisory	FSD	34 hr
Apr 5, 3:44 AM CDT	Fire Weather Watch	FSD	22 hr
Apr 5, 1:58 PM CDT	Wind Advisory	FSD	35 hr
Apr 6, 2:03 AM CDT	Red Flag Warning	FSD	17 hr
Apr 7, 2:05 PM CDT	Mesoscale Discussion	SPC	2 hr
Apr 10, 3:18 AM CDT	Fire Weather Watch	FSD	31 hr
Apr 12, 3:21 PM CDT	Fire Weather Watch	FSD	13 hr
Apr 13, 4:10 AM CDT	Red Flag Warning	FSD	15 hr
Apr 14, 1:39 PM CDT	Fire Weather Watch	FSD	15 hr
Apr 15, 4:29 AM CDT	Red Flag Warning	FSD	16 hr
Apr 16, 2:56 AM CDT	Wind Advisory	FSD	16 hr
Apr 16, 11:43 AM CDT	Mesoscale Discussion	SPC	92 min
Apr 16, 12:23 PM CDT	Tornado Watch	SPC	7 hr
Apr 16, 1:58 PM CDT	Tornado Warning Tornado observed	FSD	32 min
Apr 16, 2:03 PM CDT	Mesoscale Discussion	SPC	87 min
Apr 16, 2:15 PM CDT	Tornado Warning	FSD	30 min
Apr 16, 2:22 PM CDT	Tornado Warning	FSD	23 min
Apr 16, 2:38 PM CDT	Tornado Warning Tornado observed	FSD	22 min
Apr 16, 2:49 PM CDT	Tornado Warning	FSD	11 min
Apr 16, 2:59 PM CDT	Tornado Warning	FSD	31 min
Apr 16, 3:36 PM CDT	Mesoscale Discussion	SPC	54 min
Apr 18, 2:30 PM CDT	Freeze Warning	FSD	18 hr
Apr 19, 1:08 PM CDT	Freeze Warning	FSD	18 hr
Apr 20, 1:53 PM CDT	Freeze Warning	FSD	18 hr
Apr 22, 3:23 AM CDT	Wind Advisory	FSD	14 hr
Apr 30, 2:29 PM CDT	Mesoscale Discussion	SPC	2 hr
Apr 30, 3:44 PM CDT	Severe Thunderstorm Warning	FSD	31 min
May 5, 2:31 PM CDT	Wind Advisory	FSD	28 hr
May 6, 6:18 PM CDT	Mesoscale Discussion	SPC	117 min
May 6, 7:48 PM CDT	Tornado Warning	FSD	27 min
May 8, 2:17 PM CDT	Mesoscale Discussion	SPC	88 min
May 8, 4:11 PM CDT	Severe Thunderstorm Warning	FSD	34 min
May 20, 5:54 PM CDT	Mesoscale Discussion	SPC	2 hr
May 20, 6:45 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
May 20, 7:39 PM CDT	Severe Thunderstorm Warning	FSD	51 min
May 20, 9:23 PM CDT	Mesoscale Discussion	SPC	97 min
May 21, 2:38 AM CDT	Wind Advisory	FSD	19 hr
May 21, 8:55 AM CDT	River Flood Warning	FSD	51 hr
May 21, 11:10 AM CDT	Tornado Watch	SPC	5 hr
May 23, 8:43 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
May 31, 6:51 PM CDT	Areal Flood Warning	FSD	6 hr
Jun 1, 2:40 AM CDT	River Flood Warning	FSD	12 hr
Jun 3, 12:33 AM CDT	Severe Thunderstorm Warning	FSD	27 min
Jun 4, 12:24 PM CDT	Mesoscale Discussion	SPC	3 hr
Jun 5, 3:06 AM CDT	Wind Advisory	FSD	16 hr
Jun 6, 11:37 AM CDT	Wind Advisory	FSD	7 hr
Jun 12, 7:16 AM CDT	Mesoscale Discussion	SPC	89 min
Jun 12, 2:34 PM CDT	Mesoscale Discussion	SPC	116 min
Jun 15, 3:52 PM CDT	Tornado Watch	SPC	6 hr
Jun 17, 2:55 AM CDT	Mesoscale Discussion	SPC	95 min
Jun 17, 3:09 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 17, 2:34 PM CDT	Mesoscale Discussion	SPC	116 min
Jun 18, 12:54 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 18, 1:47 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 20, 3:26 AM CDT	Flood Watch	FSD	64 hr
Jun 20, 3:44 PM CDT	Flash Flood Warning	FSD	3 hr
Jun 20, 11:37 PM CDT	Mesoscale Discussion	SPC	83 min
Jun 21, 12:22 AM CDT	Flash Flood Warning	FSD	9 hr
Jun 21, 1:24 AM CDT	River Flood Warning	FSD	21 days
Jun 21, 1:24 AM CDT	River Flood Warning	FSD	21 days
Jun 21, 1:24 AM CDT	River Flood Warning	FSD	3 days
Jun 21, 1:24 AM CDT	River Flood Warning	FSD	4 days
Jun 21, 1:24 AM CDT	River Flood Warning	FSD	5 days
Jun 21, 2:29 AM CDT	Flash Flood Warning	FSD	7 hr
Jun 21, 3:45 AM CDT	Flash Flood Warning	FSD	6 hr
Jun 21, 4:11 AM CDT	River Flood Warning	FSD	12 hr
Jun 21, 8:02 AM CDT	Areal Flood Warning	FSD	3 days
Jun 21, 12:41 PM CDT	River Flood Warning	FSD	72 hr
Jun 21, 1:25 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 21, 3:29 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 21, 3:46 PM CDT	Tornado Warning	FSD	29 min
Jun 21, 6:18 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 21, 7:33 PM CDT	Flash Flood Warning	FSD	4 hr
Jun 21, 8:19 PM CDT	Flash Flood Warning	FSD	4 hr
Jun 21, 8:25 PM CDT	Mesoscale Discussion	SPC	95 min
Jun 21, 9:25 PM CDT	Flash Flood Warning	FSD	4 hr
Jun 21, 9:44 PM CDT	Tornado Warning	FSD	17 min
Jun 22, 1:30 AM CDT	Areal Flood Warning	FSD	59 hr
Jun 22, 1:56 AM CDT	Flash Flood Warning EmergencyCatastrophic damage threat	FSD	3 hr
Jun 22, 3:40 AM CDT	River Flood Warning	FSD	21 days
Jun 23, 2:59 AM CDT	Heat Advisory	FSD	41 hr
Jun 24, 1:01 PM CDT	Areal Flood Warning	FSD	24 hr
Jul 1, 12:08 PM CDT	Flood Watch	FSD	15 hr
Jul 10, 2:26 PM CDT	Severe Thunderstorm Warning	FSD	49 min
Jul 10, 2:55 PM CDT	Severe Thunderstorm Warning	FSD	19 min
Jul 12, 2:01 PM CDT	Heat Advisory	FSD	30 hr
Jul 13, 2:09 PM CDT	Heat Advisory	FSD	30 hr
Jul 14, 2:02 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 14, 3:58 AM CDT	Mesoscale Discussion	SPC	2 hr
Jul 14, 5:31 AM CDT	Severe Thunderstorm Warning	FSD	22 min
Jul 21, 4:07 AM CDT	Dense Fog Advisory	FSD	5 hr
Jul 29, 7:56 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 29, 8:47 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 29, 11:18 PM CDT	Severe Thunderstorm Warning	FSD	42 min
Jul 30, 5:09 AM CDT	Severe Thunderstorm Warning	FSD	51 min
Jul 30, 8:14 AM CDT	Severe Thunderstorm Warning	FSD	28 min
Jul 31, 8:55 PM CDT	Mesoscale Discussion	SPC	2 hr
Aug 5, 2:06 PM CDT	Mesoscale Discussion	SPC	114 min
Aug 23, 1:59 PM CDT	Heat Advisory	FSD	54 hr
Aug 24, 1:53 PM CDT	Excessive Heat Warning	FSD	30 hr
Aug 25, 1:34 AM CDT	Heat Advisory	FSD	42 hr
Aug 25, 7:55 AM CDT	Dense Fog Advisory	FSD	3 hr
Aug 26, 1:48 AM CDT	Excessive Heat Warning	FSD	18 hr
Aug 26, 4:39 PM CDT	Mesoscale Discussion	SPC	96 min
Aug 26, 5:49 PM CDT	Severe Thunderstorm Watch	SPC	2 hr
Aug 26, 9:28 PM CDT	Mesoscale Discussion	SPC	92 min
Aug 26, 10:55 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 27, 12:41 AM CDT	Mesoscale Discussion	SPC	94 min
Aug 28, 2:40 AM CDT	Dense Fog Advisory	FSD	9 hr
Sep 29, 3:28 PM CDT	Fire Weather Watch	FSD	11 hr
Sep 29, 3:28 PM CDT	Red Flag Warning	FSD	29 hr
Oct 1, 2:26 PM CDT	Fire Weather Watch	FSD	19 hr
Oct 2, 9:38 AM CDT	Red Flag Warning	FSD	9 hr
Oct 4, 2:41 PM CDT	Fire Weather Watch	FSD	18 hr
Oct 4, 2:41 PM CDT	Red Flag Warning	FSD	29 hr
Oct 13, 3:04 AM CDT	Frost Advisory	FSD	11 hr
Oct 13, 2:32 PM CDT	Freeze Warning	FSD	18 hr
Oct 15, 2:37 PM CDT	Fire Weather Watch	FSD	12 hr
Oct 15, 2:37 PM CDT	Fire Weather Watch	FSD	23 hr
Oct 15, 2:37 PM CDT	Red Flag Warning	FSD	28 hr
Oct 16, 2:06 PM CDT	Red Flag Warning	FSD	29 hr
Nov 3, 8:30 PM CST	Dense Fog Advisory	FSD	6 hr
Nov 5, 9:16 PM CST	Dense Fog Advisory	FSD	15 hr
Nov 10, 3:33 AM CST	Dense Fog Advisory	FSD	5 hr
Nov 14, 7:00 PM CST	Dense Fog Advisory	FSD	16 hr
Nov 18, 2:08 PM CST	Wind Advisory	FSD	58 hr
Dec 3, 1:03 PM CST	Wind Advisory	FSD	32 hr
Dec 12, 2:39 PM CST	Winter Weather Advisory	FSD	48 hr
Dec 14, 2:33 PM CST	Dense Fog Advisory	FSD	20 hr
Dec 15, 9:48 PM CST	Dense Fog Advisory	FSD	8 hr
Dec 18, 2:50 PM CST	Wind Advisory	FSD	27 hr
Dec 24, 2:06 PM CST	Dense Fog Advisory	FSD	46 hr
Dec 26, 2:03 PM CST	Dense Fog Advisory	FSD	22 hr
Dec 27, 8:14 PM CST	Dense Fog Advisory	FSD	15 hr
Dec 29, 3:57 AM CST	Dense Fog Advisory	FSD	8 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	10
Tornado Warning	9
Severe Thunderstorm Watch	9
Tornado Watch	3
Mesoscale Discussion	27
Flooding
Areal Flood Warning	4
Flash Flood Warning	8
River Flood Warning	10
Flood Watch	2
Winter
Blizzard Warning	1
Winter Storm Warning	2
Winter Storm Watch	2
Winter Weather Advisory	4
Heat
Excessive Heat Warning	2
Heat Advisory	5
Cold
Freeze Warning	4
Wind Chill Warning	1
Frost Advisory	1
Wind Chill Advisory	2
Wind and dust
Wind Advisory	11
Fire
Red Flag Warning	12
Fire Weather Watch	11
Fog and smoke
Dense Fog Advisory	23

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.