Weather alerts in Guam, 2025
117 weather alerts in 2025, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered any part of the state, so the counties below add up to more than the state.
- Alerts
- 117
- Warnings
- 11
- Watches
- 11
- Advisories
- 69
- Busiest month
- February19 alerts
- Busiest day
- November 6, 20256 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Guam, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 0 | ||||
| Flash flood warnings | 4 | 1 | 75% | 4 | 25% | 85 min |
Each office's whole area, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Guam: flash flood warnings | 4 | 1 | 75% | 4 | 25% | 85 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 | Counties | Lasted |
|---|---|---|---|---|
| Jan 4, 12:44 PM CST | Rip Current Statement | GUM | 35 hr | |
| Jan 4, 12:44 PM CST | High Surf Advisory | GUM | 35 hr | |
| Jan 6, 1:11 PM CST | Areal Flood Advisory | GUM | 79 min | |
| Jan 6, 6:56 PM CST | Areal Flood Advisory | GUM | 2 hr | |
| Jan 6, 9:13 PM CST | Areal Flood Advisory | GUM | 62 min | |
| Jan 10, 11:10 AM CST | Rip Current Statement | GUM | 8 days | |
| Jan 14, 11:42 AM CST | High Surf Advisory | GUM | 4 days | |
| Jan 18, 11:07 PM CST | Rip Current Statement | GUM | 25 hr | |
| Jan 18, 11:07 PM CST | High Surf Advisory | GUM | 25 hr | |
| Jan 27, 11:44 PM CST | Rip Current Statement | GUM | 6 days | |
| Jan 28, 11:30 PM CST | High Surf Advisory | GUM | 5 days | |
| Feb 4, 11:56 PM CST | Rip Current Statement | GUM | 71 hr | |
| Feb 4, 11:56 PM CST | High Surf Advisory | GUM | 71 hr | |
| Feb 8, 5:36 PM CST | Tsunami Advisory | HEB | 172 days | |
| Feb 8, 11:01 PM CST | Rip Current Statement | GUM | 6 days | |
| Feb 8, 11:01 PM CST | High Surf Advisory | GUM | 6 days | |
| Feb 12, 11:43 AM CST | Fire Weather Watch | GUM | 24 hr | |
| Feb 13, 11:24 AM CST | Red Flag Warning | GUM | 62 hr | |
| Feb 16, 12:47 AM CST | Fire Weather Watch | GUM | 11 hr | |
| Feb 16, 11:27 AM CST | Fire Weather Watch | GUM | 3 days | |
| Feb 16, 11:27 AM CST | Red Flag Warning | GUM | 15 hr | |
| Feb 19, 6:17 PM CST | Fire Weather Watch | GUM | 54 hr | |
| Feb 19, 6:17 PM CST | Red Flag Warning | GUM | 32 hr | |
| Feb 20, 11:14 AM CST | Rip Current Statement | GUM | 4 days | |
| Feb 20, 11:14 AM CST | High Surf Advisory | GUM | 4 days | |
| Feb 22, 8:25 PM CST | Red Flag Warning | GUM | 7 hr | |
| Feb 23, 12:20 PM CST | Fire Weather Watch | GUM | 25 hr | |
| Feb 24, 12:51 PM CST | Red Flag Warning | GUM | 37 hr | |
| Feb 25, 1:51 AM CST | Rip Current Statement | GUM | 7 days | |
| Feb 25, 1:51 AM CST | High Surf Advisory | GUM | 69 hr | |
| Mar 1, 7:09 PM CST | Areal Flood Advisory | GUM | 102 min | |
| Mar 10, 1:06 PM CDT | Rip Current Statement | GUM | 5 days | |
| Mar 10, 1:06 PM CDT | High Surf Advisory | GUM | 5 days | |
| Mar 30, 12:30 AM CDT | Rip Current Statement | GUM | 50 hr | |
| Apr 2, 12:40 AM CDT | Rip Current Statement | GUM | 3 days | |
| Apr 5, 6:31 AM CDT | Rip Current Statement | GUM | 18 hr | |
| Apr 5, 12:02 PM CDT | Fire Weather Watch | GUM | 14 hr | |
| Apr 8, 10:53 PM CDT | Beach Hazards Statement | GUM | 26 hr | |
| May 5, 11:57 AM CDT | Red Flag Warning | GUM | 10 days | |
| Jun 3, 11:13 PM CDT | Areal Flood Advisory | GUM | 107 min | |
| Jun 5, 2:49 PM CDT | Areal Flood Advisory | GUM | 116 min | |
| Jun 5, 6:56 PM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Jun 5, 8:06 PM CDT | Areal Flood Advisory | GUM | 3 hr | |
| Jun 24, 11:50 PM CDT | Flood Watch | GUM | 6 days | |
| Jun 25, 12:50 PM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Jul 4, 10:33 PM CDT | Areal Flood Advisory | GUM | 117 min | |
| Jul 6, 9:43 AM CDT | Areal Flood Advisory | GUM | 62 min | |
| Jul 6, 8:08 PM CDT | Areal Flood Advisory | GUM | 112 min | |
| Jul 8, 4:00 PM CDT | Areal Flood Advisory | GUM | 60 min | |
| Jul 19, 2:35 PM CDT | Areal Flood Advisory | GUM | 55 min | |
| Jul 19, 11:27 PM CDT | Flash Flood Warning | GUM | 2 hr | |
| Jul 22, 12:13 PM CDT | Flood Watch | GUM | 4 days | |
| Jul 23, 1:15 AM CDT | Rip Current Statement | GUM | 6 days | |
| Jul 23, 1:15 AM CDT | High Surf Advisory | GUM | 6 days | |
| Jul 23, 5:00 PM CDT | Wind Advisory | GUM | 70 hr | |
| Jul 25, 4:39 PM CDT | Coastal Flood Advisory | GUM | 44 hr | |
| Jul 26, 9:32 PM CDT | Areal Flood Advisory | GUM | 118 min | |
| Jul 29, 10:35 PM CDT | Areal Flood Advisory | GUM | 115 min | |
| Jul 30, 12:42 AM CDT | Rip Current Statement | GUM | 12 hr | |
| Aug 1, 3:50 AM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Aug 6, 7:53 PM CDT | Areal Flood Advisory | GUM | 82 min | |
| Aug 11, 5:02 AM CDT | Areal Flood Advisory | GUM | 58 min | |
| Aug 14, 5:01 AM CDT | Areal Flood Advisory | GUM | 3 hr | |
| Aug 19, 2:35 AM CDT | Areal Flood Advisory | GUM | 70 min | |
| Aug 20, 10:13 PM CDT | Areal Flood Advisory | GUM | 107 min | |
| Aug 21, 3:57 PM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Aug 21, 6:38 PM CDT | Areal Flood Advisory | GUM | 3 hr | |
| Aug 22, 6:15 PM CDT | Areal Flood Advisory | GUM | 78 min | |
| Aug 29, 3:41 PM CDT | Areal Flood Advisory | GUM | 109 min | |
| Aug 31, 9:51 PM CDT | Areal Flood Advisory | GUM | 114 min | |
| Sep 2, 12:19 AM CDT | Areal Flood Advisory | GUM | 85 min | |
| Sep 6, 11:48 PM CDT | Flash Flood Warning | GUM | 61 min | |
| Sep 15, 8:37 PM CDT | Areal Flood Advisory | GUM | 38 min | |
| Sep 24, 11:46 PM CDT | Rip Current Statement | GUM | 49 hr | |
| Sep 24, 11:46 PM CDT | High Surf Advisory | GUM | 49 hr | |
| Sep 27, 9:50 PM CDT | Areal Flood Advisory | GUM | 85 min | |
| Oct 4, 9:48 PM CDT | Areal Flood Advisory | GUM | 117 min | |
| Oct 4, 9:54 PM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Oct 6, 10:00 AM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Oct 9, 6:31 PM CDT | Areal Flood Advisory | GUM | 119 min | |
| Oct 13, 10:10 PM CDT | Flood Watch | GUM | 27 hr | |
| Oct 14, 12:43 PM CDT | Areal Flood Advisory | GUM | 77 min | |
| Oct 14, 2:38 PM CDT | Flash Flood Warning | GUM | 98 min | |
| Oct 14, 4:29 PM CDT | Areal Flood Advisory | GUM | 87 min | |
| Oct 17, 10:25 PM CDT | Areal Flood Advisory | GUM | 2 hr | |
| Oct 19, 6:49 PM CDT | Wind Advisory | GUM | 2 hr | |
| Oct 19, 7:23 PM CDT | Areal Flood Advisory | GUM | 92 min | |
| Oct 21, 2:52 AM CDT | Areal Flood Advisory | GUM | 53 min | |
| Nov 3, 1:23 PM CST | Flood Watch | GUM | 37 hr | |
| Nov 4, 12:57 AM CST | Rip Current Statement | GUM | 4 days | |
| Nov 4, 12:57 AM CST | High Surf Advisory | GUM | 4 days | |
| Nov 4, 10:36 PM CST | Wind Advisory | GUM | 24 hr | |
| Nov 5, 2:42 AM CST | Flood Watch | GUM | 42 hr | |
| Nov 5, 9:15 PM CST | Areal Flood Advisory | GUM | 30 min | |
| Nov 5, 9:41 PM CST | Flash Flood Warning | GUM | 34 min | |
| Nov 5, 11:10 PM CST | Areal Flood Advisory | GUM | 35 min | |
| Nov 5, 11:22 PM CST | Coastal Flood Statement | GUM | 23 hr | |
| Nov 5, 11:48 PM CST | Areal Flood Advisory | GUM | 57 min | |
| Nov 5, 11:54 PM CST | Areal Flood Advisory | GUM | 111 min | |
| Nov 19, 9:52 AM CST | Rip Current Statement | GUM | 7 days | |
| Nov 21, 12:36 AM CST | High Surf Advisory | GUM | 11 hr | |
| Nov 28, 11:36 PM CST | Rip Current Statement | GUM | 5 days | |
| Nov 30, 2:50 AM CST | High Surf Advisory | GUM | 3 days | |
| Dec 5, 10:19 PM CST | Rip Current Statement | GUM | 50 hr | |
| Dec 5, 10:19 PM CST | High Surf Advisory | GUM | 50 hr | |
| Dec 13, 5:08 PM CST | Rip Current Statement | GUM | 55 hr | |
| Dec 17, 12:08 AM CST | Rip Current Statement | GUM | 6 days | |
| Dec 17, 12:08 AM CST | High Surf Advisory | GUM | 6 days | |
| Dec 21, 6:57 PM CST | Areal Flood Advisory | GUM | 63 min | |
| Dec 23, 11:33 AM CST | Areal Flood Advisory | GUM | 6 hr | |
| Dec 23, 12:35 PM CST | Flash Flood Warning | GUM | 85 min | |
| Dec 24, 11:36 PM CST | Rip Current Statement | GUM | 25 hr | |
| Dec 24, 11:36 PM CST | High Surf Advisory | GUM | 25 hr | |
| Dec 27, 12:59 PM CST | Rip Current Statement | GUM | 23 hr | |
| Dec 27, 11:35 PM CST | High Surf Advisory | GUM | 12 hr | |
| Dec 28, 8:36 PM CST | Rip Current Statement | GUM | 51 hr | |
| Dec 28, 8:36 PM CST | High Surf Advisory | GUM | 51 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Flooding | |
| Flash Flood Warning | 5 |
| Flood Watch | 5 |
| Areal Flood Advisory | 45 |
| Wind and dust | |
| Wind Advisory | 3 |
| Fire | |
| Red Flag Warning | 6 |
| Fire Weather Watch | 6 |
| Coast and beach | |
| Coastal Flood Advisory | 1 |
| High Surf Advisory | 19 |
| Tsunami Advisory | 1 |
| Beach Hazards Statement | 1 |
| Coastal Flood Statement | 1 |
| Rip Current Statement | 24 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe 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.