# Boston, MA king tide and flood history since 1996

> Since 1996, NOAA's Boston tide gauge has recorded water high enough for FloodRoute's model to put at least one Boston road at risk on 1,205 days, about 39 a year. The highest water was 15.16 ft on Thursday, January 4, 2018, 3.33 ft above the tide tables; at that level the model estimates 129 Boston roads were at risk, including Chelsea Street, William T. Morrissey Boulevard and Marginal Street. Those days have become more common: about 27 a year in 1996–2005, versus 48 a year in 2016–2025.

**Estimates, not records of actual flooding.** Each day is NOAA's verified high water at the tide gauge, run through FloodRoute's flood model on today's roads and elevations, in dry weather. Drains, levees, tide gates, rain, road changes and elevation error all mean real conditions differed. Not for property, real-estate, insurance, lending, engineering or legal decisions.

- Gauge: NOAA 8443970 (Boston), verified data Jan 1, 1996 – Sep 30, 2026
- Live forecast: [Boston flood forecast](https://floodroute.com/ma/boston.md)

## The biggest days

| Date | High water (Boston gauge, ft MLLW) | vs tide tables | Roads at risk | Severity | Deepest streets (model) |
|---|---|---|---|---|---|
| Jan 4, 2018 | 15.16 | +3.33 ft | 129 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Mar 2, 2018 | 14.63 | +3.25 ft | 115 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 13, 2024 | 14.41 | +2.99 ft | 112 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Dec 23, 2022 | 13.97 | +2.33 ft | 90 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Mar 3, 2018 | 13.91 | +2.68 ft | 81 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 3, 2014 | 13.83 | +1.84 ft | 70 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 10, 2024 | 13.83 | +3.21 ft | 70 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Apr 17, 2007 | 13.80 | +1.90 ft | 70 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 25, 2005 | 13.78 | +2.38 ft | 70 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Dec 27, 2010 | 13.70 | +3.59 ft | 66 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 26, 2005 | 13.66 | +2.22 ft | 66 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 27, 2015 | 13.61 | +3.29 ft | 61 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |

## Most recent days

| Date | High water (Boston gauge, ft MLLW) | vs tide tables | Roads at risk | Severity | Deepest streets (model) |
|---|---|---|---|---|---|
| Sep 29, 2026 | 11.96 | +0.86 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Sep 28, 2026 | 12.45 | +1.53 ft | 8 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Sep 27, 2026 | 12.27 | +1.66 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 14, 2026 | 12.16 | +0.85 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 12, 2026 | 12.29 | +0.90 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 11, 2026 | 12.35 | +1.06 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 10, 2026 | 11.99 | +0.93 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 17, 2026 | 12.08 | +0.66 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 16, 2026 | 12.59 | +0.91 ft | 12 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 14, 2026 | 12.54 | +0.78 ft | 10 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |

## Days with roads at risk, by year

| Year | Days | Highest water at the gauge (ft) | Most roads at risk | Record |
|---|---|---|---|---|
| [1996](https://floodroute.com/ma/boston/history/1996.md) | 35 | 12.40 | 8 | full |
| [1997](https://floodroute.com/ma/boston/history/1997.md) | 33 | 13.27 | 40 | full |
| [1998](https://floodroute.com/ma/boston/history/1998.md) | 33 | 12.79 | 16 | full |
| [1999](https://floodroute.com/ma/boston/history/1999.md) | 16 | 12.23 | 5 | full |
| [2000](https://floodroute.com/ma/boston/history/2000.md) | 28 | 12.86 | 16 | full |
| [2001](https://floodroute.com/ma/boston/history/2001.md) | 16 | 13.00 | 27 | full |
| [2002](https://floodroute.com/ma/boston/history/2002.md) | 14 | 13.45 | 46 | full |
| [2003](https://floodroute.com/ma/boston/history/2003.md) | 26 | 13.40 | 46 | full |
| [2004](https://floodroute.com/ma/boston/history/2004.md) | 24 | 12.76 | 14 | full |
| [2005](https://floodroute.com/ma/boston/history/2005.md) | 44 | 13.78 | 70 | full |
| [2006](https://floodroute.com/ma/boston/history/2006.md) | 26 | 13.57 | 61 | full |
| [2007](https://floodroute.com/ma/boston/history/2007.md) | 28 | 13.80 | 70 | full |
| [2008](https://floodroute.com/ma/boston/history/2008.md) | 28 | 12.65 | 12 | full |
| [2009](https://floodroute.com/ma/boston/history/2009.md) | 36 | 13.03 | 27 | full |
| [2010](https://floodroute.com/ma/boston/history/2010.md) | 71 | 13.70 | 66 | full |
| [2011](https://floodroute.com/ma/boston/history/2011.md) | 54 | 13.04 | 27 | full |
| [2012](https://floodroute.com/ma/boston/history/2012.md) | 46 | 13.58 | 61 | full |
| [2013](https://floodroute.com/ma/boston/history/2013.md) | 50 | 13.07 | 30 | full |
| [2014](https://floodroute.com/ma/boston/history/2014.md) | 49 | 13.83 | 70 | full |
| [2015](https://floodroute.com/ma/boston/history/2015.md) | 31 | 13.61 | 61 | full |
| [2016](https://floodroute.com/ma/boston/history/2016.md) | 41 | 13.01 | 27 | full |
| [2017](https://floodroute.com/ma/boston/history/2017.md) | 49 | 13.40 | 46 | full |
| [2018](https://floodroute.com/ma/boston/history/2018.md) | 60 | 15.16 | 129 | full |
| [2019](https://floodroute.com/ma/boston/history/2019.md) | 55 | 13.22 | 32 | full |
| [2020](https://floodroute.com/ma/boston/history/2020.md) | 45 | 13.18 | 32 | full |
| [2021](https://floodroute.com/ma/boston/history/2021.md) | 43 | 13.26 | 32 | full |
| [2022](https://floodroute.com/ma/boston/history/2022.md) | 38 | 13.97 | 90 | full |
| [2023](https://floodroute.com/ma/boston/history/2023.md) | 44 | 13.43 | 46 | full |
| [2024](https://floodroute.com/ma/boston/history/2024.md) | 64 | 14.41 | 112 | full |
| [2025](https://floodroute.com/ma/boston/history/2025.md) | 39 | 12.44 | 8 | full |
| [2026](https://floodroute.com/ma/boston/history/2026.md) | 39 | 12.80 | 16 | partial |

## Method

For every day since 1996 we take NOAA's verified highest observed water at the tide gauge, adjust it to the town's prediction station exactly as the live forecast does (the gauge's departure from the tide tables, minus the departure already built into our calibration), and run FloodRoute's flood model on today's road network and street elevations. A day counts when at least one road in the town is at or below that water level by the model's rules. Rain is not included, so wet days were likely worse.

Data: [CSV](https://floodroute.com/data/history/ma/boston.csv) · [JSON](https://floodroute.com/data/history/ma/boston.json) · Open Database License (ODbL) 1.0 (https://opendatacommons.org/licenses/odbl/1-0/) · Credit: FloodRoute (floodroute.com), © OpenStreetMap contributors, NOAA CO-OPS · [All towns](https://floodroute.com/data.md)

## Frequently asked questions

### How often do roads flood at high tide in Boston?

By FloodRoute's estimate, at least one Boston road was at risk on 1,205 days between 1996 and Sep 30, 2026, about 39 a year. Those days have become more common: about 27 a year in 1996–2005, versus 48 a year in 2016–2025. Most of those days are shallow water on a few low streets; the [biggest days](https://floodroute.com/ma/boston/history) put dozens of roads at risk.

### What was the highest tide in Boston since 1996?

Thursday, January 4, 2018: NOAA's Boston tide gauge recorded 15.16 ft (MLLW), 3.33 ft above the tide tables. At that level FloodRoute's model estimates 129 Boston roads were at risk, including Chelsea Street, William T. Morrissey Boulevard and Marginal Street.

### When did a high tide last put Boston roads at risk?

The most recent day in the verified record is Tuesday, September 29, 2026: 11.96 ft at the Boston gauge, 4 roads at risk. NOAA verifies data with a lag of a month or two; the [live forecast](https://floodroute.com/ma/boston) covers today and the weeks ahead.

### Is this a record of actual flooding in Boston?

No. Estimates, not records of actual flooding. Each day is NOAA's verified high water at the tide gauge, run through FloodRoute's flood model on today's roads and elevations, in dry weather. Drains, levees, tide gates, rain, road changes and elevation error all mean real conditions differed. Not for property, real-estate, insurance, lending, engineering or legal decisions. Neighbor flood reports in the FloodRoute app are the ground truth we use to check and improve the model.

### Can I use this data?

Yes. Download it as [CSV](https://floodroute.com/data/history/ma/boston.csv) or [JSON](https://floodroute.com/data/history/ma/boston.json) under the Open Database License (ODbL) 1.0, with attribution to FloodRoute (floodroute.com), © OpenStreetMap contributors, NOAA CO-OPS. Please describe it as estimates, never as observed flooding. More on the [open data page](https://floodroute.com/data).

**Forecasts are estimates, not guarantees.** Never drive or walk through flood water: according to the National Weather Service, a foot of moving water can carry away most cars. Turn around, don’t drown. Always follow local authorities and official warnings.

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Web version: https://floodroute.com/ma/boston/history · Site index for AI agents: https://floodroute.com/llms.txt · Every page is available as Markdown: add `.md` to its URL.

FloodRoute provides estimates only. Never drive or walk through flood water. © Axiomic, LLC · contact@axiomic.ai