Alert archive / Iowa / O'Brien County

Weather alerts in O'Brien County, Iowa, 2025

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

O'Brien County and its neighbors

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

Alerts
165
Warnings
54
Watches
28
Advisories
51
Busiest month
July39 alerts
Busiest day
July 28, 20259 alerts

Over time

By month

Warning verification

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

1 of 1 tornado warnings covering O'Brien County in 2025 had a tornado report inside them.

O'Brien County, 2025

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings110%0
Severe thunderstorm warnings291838%1191%15 min
Flash flood warnings4175%10%

Each office's whole area, 2025

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sioux Falls, SD: tornado warnings20575%956%8 min
NWS Sioux Falls, SD: severe thunderstorm warnings33219142%50085%22 min
NWS Sioux Falls, SD: flash flood warnings25964%1974%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.

IssuedProductOfficeLasted
Jan 17, 1:13 PM CSTCold Weather AdvisoryFSD47 hr
Jan 18, 1:24 PM CSTCold Weather AdvisoryFSD71 hr
Jan 20, 2:45 AM CSTExtreme Cold WarningFSD33 hr
Jan 28, 1:33 PM CSTRed Flag WarningFSD4 hr
Feb 1, 2:44 AM CSTWind AdvisoryFSD12 hr
Feb 2, 2:07 AM CSTDense Fog AdvisoryFSD9 hr
Feb 6, 3:23 AM CSTWind AdvisoryFSD15 hr
Feb 10, 2:13 AM CSTWinter Weather AdvisoryFSD22 hr
Feb 10, 2:26 PM CSTCold Weather AdvisoryFSD19 hr
Feb 12, 2:49 AM CSTCold Weather AdvisoryFSD30 hr
Feb 14, 1:14 PM CSTWinter Weather AdvisoryFSD22 hr
Feb 16, 3:02 AM CSTCold Weather AdvisoryFSD42 hr
Feb 16, 3:02 AM CSTExtreme Cold WatchFSD24 hr
Feb 17, 2:57 AM CSTExtreme Cold WarningFSD33 hr
Feb 17, 11:50 AM CSTCold Weather AdvisoryFSD9 hr
Feb 18, 3:09 AM CSTCold Weather AdvisoryFSD31 hr
Feb 19, 2:40 AM CSTCold Weather AdvisoryFSD30 hr
Feb 25, 4:14 AM CSTDense Fog AdvisoryFSD7 hr
Feb 27, 1:35 PM CSTWind AdvisoryFSD28 hr
Feb 28, 3:20 AM CSTRed Flag WarningFSD15 hr
Mar 3, 3:51 AM CSTWinter Storm WatchFSD24 hr
Mar 3, 2:10 PM CSTWinter Weather AdvisoryFSD40 hr
Mar 4, 10:49 AM CSTBlizzard WarningFSD31 hr
Mar 4, 11:22 AM CSTHigh Wind WarningFSD19 hr
Mar 4, 11:17 PM CSTMesoscale DiscussionSPC4 hr
Mar 5, 11:35 AM CSTWinter Weather AdvisoryFSD6 hr
Mar 6, 3:20 AM CSTWinter Weather AdvisoryFSD33 hr
Mar 14, 1:46 PM CDTWind AdvisoryFSD25 hr
Mar 14, 5:01 PM CDTMesoscale DiscussionSPC89 min
Mar 14, 5:43 PM CDTSevere Thunderstorm WatchSPC6 hr
Mar 14, 6:31 PM CDTSevere Thunderstorm WarningFSD44 min
Mar 14, 6:45 PM CDTSevere Thunderstorm WarningFSD45 min
Mar 17, 3:13 AM CDTWinter Storm WatchFSD24 hr
Mar 17, 3:23 AM CDTRed Flag WarningFSD16 hr
Mar 17, 2:50 PM CDTHigh Wind WatchFSD13 hr
Mar 18, 3:21 AM CDTBlizzard WarningFSD40 hr
Mar 18, 3:21 AM CDTHigh Wind WarningFSD40 hr
Mar 19, 5:54 AM CDTMesoscale DiscussionSPC5 hr
Mar 22, 2:25 PM CDTWind AdvisoryFSD29 hr
Mar 27, 2:06 PM CDTFire Weather WatchFSD14 hr
Mar 28, 3:43 AM CDTRed Flag WarningFSD16 hr
Mar 28, 7:25 PM CDTMesoscale DiscussionSPC2 hr
Apr 9, 2:23 AM CDTRed Flag WarningFSD18 hr
Apr 14, 3:10 AM CDTWind AdvisoryFSD16 hr
Apr 14, 1:28 PM CDTMesoscale DiscussionSPC3 hr
Apr 17, 12:46 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 3:45 PM CDTSevere Thunderstorm WatchSPC6 hr
Apr 17, 5:56 PM CDTMesoscale DiscussionSPC2 hr
Apr 17, 8:06 PM CDTMesoscale DiscussionSPC84 min
Apr 17, 8:51 PM CDTSevere Thunderstorm WarningFSD24 min
Apr 18, 12:42 AM CDTMesoscale DiscussionSPC3 hr
Apr 18, 2:10 AM CDTSevere Thunderstorm WarningFSD35 min
Apr 28, 10:41 AM CDTMesoscale DiscussionSPC2 hr
Apr 28, 12:29 PM CDTTornado WatchSPC10 hr
Apr 28, 2:50 PM CDTSevere Thunderstorm WarningFSD21 min
Apr 28, 5:59 PM CDTSevere Thunderstorm WatchSPC4 hr
Apr 28, 6:06 PM CDTSevere Thunderstorm WarningFSD39 min
May 10, 2:05 PM CDTRed Flag WarningFSD32 hr
May 14, 2:00 PM CDTWind AdvisoryFSD53 hr
May 15, 1:08 AM CDTMesoscale DiscussionSPC97 min
May 15, 1:36 AM CDTSevere Thunderstorm WatchSPC6 hr
May 15, 4:04 AM CDTMesoscale DiscussionSPC86 min
May 15, 2:15 PM CDTWind AdvisoryFSD29 hr
May 19, 8:25 PM CDTHigh Wind WarningFSD4 hr
Jun 2, 1:20 PM CDTMesoscale DiscussionSPC85 min
Jun 2, 3:47 PM CDTMesoscale DiscussionSPC118 min
Jun 2, 4:50 PM CDTSevere Thunderstorm WatchSPC8 hr
Jun 2, 5:41 PM CDTSevere Thunderstorm WarningFSD49 min
Jun 2, 6:23 PM CDTSevere Thunderstorm WarningFSD52 min
Jun 11, 1:56 PM CDTMesoscale DiscussionSPC3 hr
Jun 11, 2:21 PM CDTSevere Thunderstorm Warning Considerable damage threatFSD24 min
Jun 11, 2:53 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 14, 4:37 AM CDTDense Fog AdvisoryFSD4 hr
Jun 14, 6:47 PM CDTMesoscale DiscussionSPC118 min
Jun 16, 5:33 PM CDTSevere Thunderstorm Warning Considerable damage threatFSD42 min
Jun 18, 2:02 PM CDTExtreme Heat WatchFSD23 hr
Jun 19, 1:30 PM CDTExtreme Heat WarningFSD3 days
Jun 25, 11:13 AM CDTFlood WatchFSD20 hr
Jun 25, 2:38 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 27, 10:29 PM CDTSevere Thunderstorm WatchSPC5 hr
Jun 28, 11:12 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 29, 1:01 AM CDTMesoscale DiscussionSPC119 min
Jun 29, 3:38 AM CDTSevere Thunderstorm WarningFSD37 min
Jun 29, 4:06 AM CDTSevere Thunderstorm WarningFSD39 min
Jul 2, 11:52 PM CDTMesoscale DiscussionSPC113 min
Jul 7, 3:14 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 10, 1:39 AM CDTMesoscale DiscussionSPC2 hr
Jul 15, 8:19 PM CDTMesoscale DiscussionSPC86 min
Jul 15, 8:41 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 18, 8:06 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 18, 11:30 PM CDTMesoscale DiscussionSPC90 min
Jul 19, 1:54 AM CDTMesoscale DiscussionSPC96 min
Jul 19, 2:48 AM CDTSevere Thunderstorm WarningFSD27 min
Jul 19, 3:08 AM CDTSevere Thunderstorm Warning Considerable damage threatFSD52 min
Jul 20, 2:19 PM CDTHeat AdvisoryFSD30 hr
Jul 22, 3:23 AM CDTHeat AdvisoryFSD17 hr
Jul 22, 2:13 PM CDTHeat AdvisoryFSD30 hr
Jul 26, 2:53 AM CDTExtreme Heat WatchFSD11 hr
Jul 26, 4:32 AM CDTDense Fog AdvisoryFSD4 hr
Jul 26, 2:08 PM CDTExtreme Heat WarningFSD30 hr
Jul 27, 2:34 PM CDTExtreme Heat WarningFSD29 hr
Jul 27, 4:47 PM CDTSevere Thunderstorm WatchSPC9 hr
Jul 27, 9:47 PM CDTMesoscale DiscussionSPC118 min
Jul 28, 12:01 AM CDTSevere Thunderstorm WarningFSD44 min
Jul 28, 12:30 AM CDTSevere Thunderstorm WarningFSD45 min
Jul 28, 12:42 AM CDTSevere Thunderstorm WarningFSD48 min
Jul 28, 1:15 AM CDTSevere Thunderstorm WarningFSD45 min
Jul 28, 1:29 AM CDTSevere Thunderstorm WarningFSD46 min
Jul 28, 1:44 AM CDTFlash Flood WarningFSD91 min
Jul 28, 1:57 AM CDTSevere Thunderstorm WarningFSD48 min
Jul 28, 6:57 PM CDTSevere Thunderstorm WatchSPC5 hr
Jul 28, 8:13 PM CDTMesoscale DiscussionSPC2 hr
Jul 28, 9:23 PM CDTSevere Thunderstorm Warning Destructive damage threatFSD37 min
Jul 28, 9:34 PM CDTTornado WarningFSD26 min
Jul 28, 9:39 PM CDTMesoscale DiscussionSPC2 hr
Jul 28, 9:55 PM CDTSevere Thunderstorm Warning Destructive damage threatFSD80 min
Jul 28, 11:10 PM CDTSevere Thunderstorm WarningFSD35 min
Jul 29, 8:27 AM CDTSevere Thunderstorm WarningFSD19 min
Jul 29, 2:29 PM CDTFlood WatchFSD11 hr
Jul 29, 7:30 PM CDTMesoscale DiscussionSPC90 min
Jul 29, 8:24 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 29, 9:45 PM CDTSevere Thunderstorm WarningFSD46 min
Jul 29, 10:19 PM CDTFlash Flood WarningFSD4 hr
Aug 5, 11:33 PM CDTMesoscale DiscussionSPC117 min
Aug 7, 2:15 PM CDTHeat AdvisoryFSD30 hr
Aug 8, 9:34 PM CDTSevere Thunderstorm WatchSPC8 hr
Aug 9, 2:40 AM CDTMesoscale DiscussionSPC95 min
Aug 15, 11:31 AM CDTSevere Thunderstorm WarningFSD59 min
Aug 15, 1:59 PM CDTHeat AdvisoryFSD30 hr
Aug 18, 1:50 AM CDTMesoscale DiscussionSPC85 min
Aug 30, 4:01 PM CDTFlash Flood WarningFSD119 min
Sep 4, 4:56 PM CDTMesoscale DiscussionSPC94 min
Sep 6, 4:17 PM CDTFrost AdvisoryFSD17 hr
Sep 9, 10:49 PM CDTDense Fog AdvisoryFSD12 hr
Sep 16, 2:21 PM CDTMesoscale DiscussionSPC114 min
Sep 16, 9:09 PM CDTFlash Flood WarningFSD63 min
Sep 16, 9:23 PM CDTSevere Thunderstorm WarningFSD39 min
Sep 22, 6:31 PM CDTSevere Thunderstorm WarningFSD44 min
Sep 22, 7:14 PM CDTSevere Thunderstorm WarningFSD46 min
Oct 15, 7:31 PM CDTDense Fog AdvisoryFSD8 hr
Oct 20, 2:36 PM CDTWind AdvisoryFSD27 hr
Oct 28, 10:51 AM CDTWind AdvisoryFSD16 hr
Oct 30, 1:31 AM CDTDense Fog AdvisoryFSD9 hr
Nov 7, 9:12 PM CSTWinter Weather AdvisoryFSD17 hr
Nov 20, 4:13 AM CSTDense Fog AdvisoryFSD8 hr
Nov 24, 1:42 PM CSTWind AdvisoryFSD37 hr
Nov 25, 4:34 AM CSTDense Fog AdvisoryFSD4 hr
Nov 26, 2:26 PM CSTWinter Storm WatchFSD24 hr
Nov 27, 2:53 PM CSTWinter Storm WarningFSD57 hr
Dec 5, 3:33 AM CSTWinter Weather AdvisoryFSD44 hr
Dec 6, 3:08 AM CSTWinter Storm WarningFSD21 hr
Dec 6, 12:25 PM CSTMesoscale DiscussionSPC6 hr
Dec 8, 5:35 AM CSTDense Fog AdvisoryFSD15 hr
Dec 8, 2:45 PM CSTHigh Wind WarningFSD39 hr
Dec 8, 2:45 PM CSTWinter Storm WatchFSD21 hr
Dec 10, 3:13 AM CSTWinter Weather AdvisoryFSD39 hr
Dec 12, 2:24 AM CSTWinter Weather AdvisoryFSD34 hr
Dec 12, 2:08 PM CSTCold Weather AdvisoryFSD44 hr
Dec 17, 2:43 AM CSTWind AdvisoryFSD42 hr
Dec 18, 6:47 AM CSTWinter Weather AdvisoryFSD11 hr
Dec 24, 1:19 PM CSTDense Fog AdvisoryFSD68 hr
Dec 27, 12:47 PM CSTDense Fog AdvisoryFSD17 hr
Dec 27, 2:10 PM CSTWind AdvisoryFSD34 hr
Dec 27, 2:11 PM CSTWinter Weather AdvisoryFSD40 hr
Dec 28, 10:56 AM CSTBlizzard WarningFSD19 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 archive20242026

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.