Alert archive / South Dakota / Gregory County

Weather alerts in Gregory County, South Dakota, 2025

157 weather alerts in 2025, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Gregory County and its neighbors

Each county as a circle sized by its count in 2025. Tap one for its archive.

Alerts: 157
Warnings: 60
Watches: 29
Advisories: 40
Busiest month: July47 alerts
Busiest day: July 28, 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.

4 of 7 tornado warnings covering Gregory County in 2025 had a tornado report inside them; 4 of 5 tornado reports fell inside a warning, on average 10 minutes after it went out.

Gregory County, 2025

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	7	4	43%	5	80%	10 min
Severe thunderstorm warnings	29	21	28%	16	75%	21 min
Flash flood warnings	0			0

Each office's whole area, 2025

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Sioux Falls, SD: tornado warnings	20	5	75%	9	56%	8 min
NWS Sioux Falls, SD: severe thunderstorm warnings	332	191	42%	500	85%	22 min
NWS Sioux Falls, SD: flash flood warnings	25	9	64%	19	74%	80 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 4, 3:38 AM CST	Winter Weather Advisory	FSD	26 hr
Jan 17, 11:30 AM CST	Wind Advisory	FSD	7 hr
Jan 17, 1:13 PM CST	Cold Weather Advisory	FSD	47 hr
Jan 18, 1:24 PM CST	Cold Weather Advisory	FSD	71 hr
Jan 20, 2:45 AM CST	Cold Weather Advisory	FSD	33 hr
Jan 20, 2:45 AM CST	Extreme Cold Warning	FSD	33 hr
Feb 12, 2:49 AM CST	Cold Weather Advisory	FSD	30 hr
Feb 16, 3:02 AM CST	Cold Weather Advisory	FSD	42 hr
Feb 17, 2:57 AM CST	Extreme Cold Warning	FSD	33 hr
Feb 18, 3:09 AM CST	Cold Weather Advisory	FSD	31 hr
Feb 19, 2:40 AM CST	Cold Weather Advisory	FSD	30 hr
Feb 24, 1:31 PM CST	Wind Advisory	FSD	5 hr
Feb 25, 2:53 AM CST	Red Flag Warning	FSD	16 hr
Feb 27, 1:35 PM CST	Wind Advisory	FSD	28 hr
Feb 27, 1:38 PM CST	Fire Weather Watch	FSD	14 hr
Feb 28, 3:20 AM CST	Red Flag Warning	FSD	15 hr
Mar 3, 3:51 AM CST	Winter Storm Watch	FSD	24 hr
Mar 3, 2:10 PM CST	Winter Weather Advisory	FSD	40 hr
Mar 4, 10:25 AM CST	Mesoscale Discussion	SPC	4 hr
Mar 6, 3:20 AM CST	Winter Weather Advisory	FSD	33 hr
Mar 6, 1:28 PM CST	Winter Storm Warning	FSD	13 hr
Mar 12, 3:19 AM CDT	Fire Weather Watch	FSD	9 hr
Mar 12, 12:47 PM CDT	Red Flag Warning	FSD	31 hr
Mar 13, 3:30 AM CDT	High Wind Watch	FSD	24 hr
Mar 14, 3:21 AM CDT	High Wind Warning	FSD	35 hr
Mar 14, 1:46 PM CDT	Wind Advisory	FSD	25 hr
Mar 16, 1:39 PM CDT	Fire Weather Watch	FSD	14 hr
Mar 17, 3:23 AM CDT	Red Flag Warning	FSD	16 hr
Mar 20, 3:19 AM CDT	Red Flag Warning	FSD	16 hr
Mar 21, 2:44 PM CDT	Red Flag Warning	FSD	29 hr
Mar 22, 2:25 PM CDT	Wind Advisory	FSD	29 hr
Mar 29, 3:33 AM CDT	Winter Weather Advisory	FSD	33 hr
Apr 8, 2:23 PM CDT	Fire Weather Watch	FSD	12 hr
Apr 9, 2:23 AM CDT	Red Flag Warning	FSD	18 hr
Apr 10, 2:36 AM CDT	Red Flag Warning	FSD	17 hr
Apr 12, 1:54 PM CDT	Fire Weather Watch	FSD	13 hr
Apr 13, 2:39 AM CDT	Wind Advisory	FSD	25 hr
Apr 13, 2:46 AM CDT	Red Flag Warning	FSD	19 hr
Apr 13, 2:24 PM CDT	Fire Weather Watch	FSD	13 hr
Apr 14, 3:10 AM CDT	Wind Advisory	FSD	16 hr
Apr 14, 3:12 AM CDT	Red Flag Warning	FSD	17 hr
Apr 27, 11:33 PM CDT	Mesoscale Discussion	SPC	87 min
Apr 28, 12:58 AM CDT	Mesoscale Discussion	SPC	92 min
Apr 28, 5:22 PM CDT	Severe Thunderstorm Warning	FSD	38 min
May 8, 2:35 PM CDT	Fire Weather Watch	FSD	48 hr
May 10, 2:05 PM CDT	Fire Weather Watch	FSD	32 hr
May 10, 2:05 PM CDT	Red Flag Warning	FSD	32 hr
May 11, 9:50 PM CDT	Red Flag Warning	FSD	23 hr
May 12, 1:42 PM CDT	Fire Weather Watch	FSD	14 hr
May 13, 3:33 AM CDT	Red Flag Warning	FSD	17 hr
May 14, 2:00 PM CDT	Wind Advisory	FSD	53 hr
May 14, 8:01 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
May 14, 10:18 PM CDT	Severe Thunderstorm Warning	FSD	27 min
May 16, 4:10 AM CDT	High Wind Warning	FSD	13 hr
May 28, 2:55 AM CDT	Dense Fog Advisory	FSD	6 hr
Jun 12, 3:19 PM CDT	Mesoscale Discussion	SPC	116 min
Jun 12, 3:53 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 12, 6:08 PM CDT	Mesoscale Discussion	SPC	97 min
Jun 14, 4:37 AM CDT	Dense Fog Advisory	FSD	4 hr
Jun 16, 5:03 AM CDT	Wind Advisory	FSD	3 hr
Jun 18, 2:02 PM CDT	Extreme Heat Watch	FSD	23 hr
Jun 19, 1:30 PM CDT	Heat Advisory	FSD	3 days
Jun 19, 6:34 PM CDT	Severe Thunderstorm Warning	FSD	41 min
Jun 22, 3:59 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 22, 7:55 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 22, 10:03 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 27, 5:16 AM CDT	Dense Fog Advisory	FSD	5 hr
Jun 27, 5:45 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 27, 8:19 PM CDT	Severe Thunderstorm Warning	FSD	41 min
Jun 27, 8:41 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	49 min
Jun 27, 9:18 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 27, 9:24 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	51 min
Jun 28, 10:01 PM CDT	Mesoscale Discussion	SPC	119 min
Jun 28, 10:30 PM CDT	Severe Thunderstorm Warning	FSD	60 min
Jul 7, 1:11 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 7, 3:14 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 7, 3:49 PM CDT	Severe Thunderstorm Warning	FSD	41 min
Jul 7, 3:59 PM CDT	Severe Thunderstorm Warning	FSD	46 min
Jul 7, 5:52 PM CDT	Mesoscale Discussion	SPC	83 min
Jul 9, 7:36 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 9, 8:26 PM CDT	Mesoscale Discussion	SPC	94 min
Jul 9, 8:35 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	55 min
Jul 9, 9:30 PM CDT	Severe Thunderstorm Warning	FSD	75 min
Jul 15, 2:58 PM CDT	Mesoscale Discussion	SPC	3 hr
Jul 15, 3:53 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 15, 4:24 PM CDT	Severe Thunderstorm Warning	FSD	51 min
Jul 15, 5:08 PM CDT	Tornado Warning	FSD	26 min
Jul 15, 5:11 PM CDT	Severe Thunderstorm Warning	FSD	49 min
Jul 15, 5:23 PM CDT	Severe Thunderstorm Warning	FSD	37 min
Jul 15, 5:46 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	59 min
Jul 18, 7:19 PM CDT	Mesoscale Discussion	SPC	116 min
Jul 18, 8:06 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 18, 10:50 PM CDT	Severe Thunderstorm Warning	FSD	26 min
Jul 18, 11:30 PM CDT	Mesoscale Discussion	SPC	90 min
Jul 20, 2:19 PM CDT	Heat Advisory	FSD	30 hr
Jul 22, 3:23 AM CDT	Heat Advisory	FSD	17 hr
Jul 25, 2:56 AM CDT	Heat Advisory	FSD	41 hr
Jul 26, 2:53 AM CDT	Extreme Heat Watch	FSD	11 hr
Jul 26, 2:08 PM CDT	Extreme Heat Warning	FSD	30 hr
Jul 27, 2:34 PM CDT	Extreme Heat Warning	FSD	29 hr
Jul 27, 4:47 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 27, 6:33 PM CDT	Mesoscale Discussion	SPC	117 min
Jul 28, 2:47 PM CDT	Mesoscale Discussion	SPC	118 min
Jul 28, 3:46 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 28, 4:15 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	45 min
Jul 28, 4:34 PM CDT	Tornado Warning	FSD	26 min
Jul 28, 5:01 PM CDT	Tornado Warning	FSD	29 min
Jul 28, 5:19 PM CDT	Tornado Warning Tornado observed	FSD	26 min
Jul 28, 5:40 PM CDT	Severe Thunderstorm Warning Destructive damage threat	FSD	50 min
Jul 28, 5:46 PM CDT	Tornado Warning Tornado observed	FSD	29 min
Jul 28, 5:49 PM CDT	Mesoscale Discussion	SPC	116 min
Jul 28, 6:10 PM CDT	Tornado Warning Tornado observed	FSD	50 min
Jul 28, 6:22 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	38 min
Jul 28, 6:54 PM CDT	Tornado Warning	FSD	24 min
Jul 28, 6:57 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	48 min
Jul 29, 4:34 PM CDT	Mesoscale Discussion	SPC	56 min
Jul 29, 4:54 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 29, 5:19 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	41 min
Jul 29, 5:56 PM CDT	Severe Thunderstorm Warning	FSD	49 min
Jul 29, 6:19 PM CDT	Severe Thunderstorm Warning	FSD	41 min
Jul 29, 6:59 PM CDT	Severe Thunderstorm Warning	FSD	25 min
Aug 3, 4:44 PM CDT	Mesoscale Discussion	SPC	2 hr
Aug 5, 8:00 PM CDT	Mesoscale Discussion	SPC	2 hr
Aug 7, 2:48 AM CDT	Heat Advisory	FSD	17 hr
Aug 7, 6:54 AM CDT	Dense Fog Advisory	FSD	3 hr
Aug 13, 3:48 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Aug 13, 5:21 PM CDT	Mesoscale Discussion	SPC	114 min
Aug 13, 7:33 PM CDT	Mesoscale Discussion	SPC	117 min
Aug 13, 9:49 PM CDT	Mesoscale Discussion	SPC	116 min
Aug 13, 10:11 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	64 min
Aug 13, 10:54 PM CDT	Severe Thunderstorm Warning	FSD	55 min
Aug 15, 1:59 PM CDT	Heat Advisory	FSD	30 hr
Aug 15, 7:21 PM CDT	Mesoscale Discussion	SPC	114 min
Aug 15, 11:58 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 16, 1:35 AM CDT	Severe Thunderstorm Warning	FSD	40 min
Aug 16, 2:10 AM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	50 min
Aug 16, 2:18 AM CDT	Mesoscale Discussion	SPC	87 min
Aug 17, 8:45 PM CDT	Mesoscale Discussion	SPC	2 hr
Aug 17, 10:19 PM CDT	Severe Thunderstorm Warning	FSD	41 min
Aug 17, 10:41 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Sep 2, 5:51 AM CDT	Dense Fog Advisory	FSD	4 hr
Sep 3, 2:15 PM CDT	Wind Advisory	FSD	31 hr
Sep 9, 10:49 PM CDT	Dense Fog Advisory	FSD	12 hr
Sep 14, 3:28 PM CDT	Mesoscale Discussion	SPC	92 min
Oct 15, 5:09 AM CDT	Dense Fog Advisory	FSD	5 hr
Oct 20, 2:50 AM CDT	Wind Advisory	FSD	31 hr
Nov 14, 2:25 AM CST	Red Flag Warning	FSD	16 hr
Nov 24, 2:21 AM CST	High Wind Watch	FSD	11 hr
Nov 24, 1:42 PM CST	High Wind Warning	FSD	34 hr
Nov 27, 2:53 PM CST	Winter Weather Advisory	FSD	57 hr
Dec 8, 2:45 PM CST	High Wind Warning	FSD	39 hr
Dec 12, 2:24 AM CST	Winter Weather Advisory	FSD	34 hr
Dec 16, 1:57 PM CST	High Wind Watch	FSD	13 hr
Dec 16, 1:57 PM CST	Wind Advisory	FSD	31 hr
Dec 17, 2:43 AM CST	High Wind Warning	FSD	42 hr
Dec 24, 1:19 PM CST	Dense Fog Advisory	FSD	68 hr
Dec 27, 2:10 PM CST	Wind Advisory	FSD	34 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	29
Tornado Warning	7
Severe Thunderstorm Watch	14
Mesoscale Discussion	28
Winter
Winter Storm Warning	1
Winter Storm Watch	1
Winter Weather Advisory	6
Heat
Extreme Heat Warning	2
Extreme Heat Watch	2
Heat Advisory	6
Cold
Extreme Cold Warning	2
Cold Weather Advisory	7
Wind and dust
High Wind Warning	5
High Wind Watch	3
Wind Advisory	13
Fire
Red Flag Warning	14
Fire Weather Watch	9
Fog and smoke
Dense Fog Advisory	8

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.