Right now
The most recent data we hold from CO OPS arrived 6 hours ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
Reported by CO OPS 38 days ago.
No stronger detection stands among the 18 recorded within 20 km of this point since 10 March 2026 — 4 others scored the same. The last comparable one was on 29 August 2026.
What the source measured
CO OPS reported: Water level 0.32m above predicted at Boston, MA. Observed: 0.61m, Predicted: 0.29m (MLLW datum).
The observed water level was 0.61 m, against 0.29 m predicted.
Urban PEI: 4,688,154 within a heuristic 50 km radius; not unique people.
Nearby, since 10 March 2026
- September 25, 2026 · 0.0 km
- September 19, 2026 · 0.0 km
- September 18, 2026 · 0.0 km
How we know
2 recorded sources include CO OPS; independence is not established by this count.
Our own score for this event is 46 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Event data
| Type | Flood |
| Severity | Medium |
| Calamity Score (ours) | 46 / 100 |
| Legacy data-support index | 0.75/1 |
| Coordinates | 42.3539, -71.0503 |
| Nearest city | Boston (1 km) |
| Urban exposure index (PEI) | 4.7M within 50 km |
| Impact tier | significant |
| Timestamp | 2026-08-30T00:12:00.000Z |
| Source | https://tidesandcurrents.noaa.gov/stationhome.html?id=8443970 |
| Licence | US public domain · NOAA CO-OPS |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: co_ops. Occurrence: 2026-08-30T00:12:00.000Z.
First archived: 2026-08-30T00:25:56.920Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score breakdown
Technical details
| StationId | 8443970 |
| StationName | Boston, MA |
| ObservedM | 0.61 |
| PredictedM | 0.29 |
| SurgeM | 0.32 |
| Datum | MLLW |
| Google News RssFeed | flood |
| Google News SourceName | NBC Boston |
| MergedSources | [{"id":"gnews_flood_496665_51","source":"google_news","severity":"medium","severityValue":40,"timestamp":1787995347000,"latitude":42.36,"longitude":-71.06}] |
Safety information
What to do in a flood
Three things first, then how little water it takes, and what to do before, during and after. From the advice of the US National Weather Service and FEMA.
For this reportFlood · Boston
In a car, turn around
Do not drive into a flooded road or around a barrier: the road under the water may be gone. More than half of flood drownings happen in vehicles.
NWSDo not walk through the water
Fifteen centimetres of moving water can knock you down. It can hide open drains and debris, and a fallen power line can make it live.
NWS · FEMAIf the water rises, go higher
With a flash flood warning, move to higher ground at once. Never into a closed attic: rising water can trap you there.
NWS · FEMA
It takes very little moving water
Moving water. Figures from the US National Weather Service, “Turn Around Don’t Drown”. Person, car and water are drawn to the same scale.
Before, during, after. Here it is “after”.
Before · When heavy rain is forecast
Get the official alerts
On your phone and from your local authorities, so a warning reaches you even at night.
Keep supplies ready
Water, food, medicine, a torch and batteries, in case you must leave fast or services stop.
Documents kept dry
In a waterproof container, with a password-protected digital copy.
Valuables up high
Move what you cannot replace to upper floors, and clear gutters and drains.
Ready.gov (FEMA)
During · While the water is rising
If told to leave, leave
When authorities order an evacuation, go at once.
Keep listening
Phone alerts, weather radio and local authorities.
Keep off bridges over fast water
A current can take a bridge away without warning.
Trapped in a car
If the water is moving fast, stay inside. If it comes into the car, get onto the roof.
Trapped in a building
Go to the highest floor, not a closed attic. Onto the roof only if you must, and make yourself seen.
Ready.gov (FEMA) · National Weather Service
After · When the water goes down
Go back when authorities say so
Until then, drive only in an emergency.
Do not touch standing water
It can carry sewage and debris; a fallen line can make it live.
Mind the electricity
Do not touch wet appliances or stand in water while using them. Switch the power off only if it is safe.
Generators outdoors only
Generators and petrol engines outside, away from windows: their fumes kill indoors.
Clean up protected
Gloves, boots and covering clothes. Children should not help.
Ready.gov (FEMA)
Questions people ask
How much water does it take to sweep a car away?
About 30 centimetres of moving water carries away most cars, and 60 centimetres SUVs and pick-ups. Fifteen are enough to knock an adult over. Source: US National Weather Service.
What is the difference between a flood watch and a flood warning?
A watch means a flood is possible: get ready. A warning means it is happening or about to: act. With a flash flood warning, go to higher ground straight away. Source: US National Weather Service.
Is it safe to walk in floodwater?
No. It can be contaminated, hide debris and open drains, and carry electricity from a fallen line. Source: Ready.gov (FEMA).
Review the area, threshold and delivery channel in your account.