# Boston king tides and high water in 2021

> In 2021, NOAA's Boston tide gauge recorded water high enough for FloodRoute's model to put at least one Boston road at risk on 43 days. The highest was 13.26 ft on Tuesday, February 2, 2021, 3.18 ft above the tide tables, with 32 roads at risk, including Chelsea Street, William T. Morrissey Boulevard and Marginal Street.

**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.

## Every day with roads at risk (43)

| Date | High water (Boston gauge, ft MLLW) | vs tide tables | Roads at risk | Severity | Deepest streets (model) |
|---|---|---|---|---|---|
| Jan 11, 2021 | 11.81 | +0.81 ft | 2 | Possible | Chelsea Street |
| Jan 12, 2021 | 11.92 | +0.77 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 13, 2021 | 12.15 | +0.99 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 14, 2021 | 12.14 | +1.12 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jan 16, 2021 | 12.67 | +2.31 ft | 14 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Feb 1, 2021 | 12.14 | +1.54 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Feb 2, 2021 | 13.26 | +3.18 ft | 32 | Severe | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Feb 3, 2021 | 12.03 | +1.85 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Mar 1, 2021 | 12.19 | +1.16 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Mar 29, 2021 | 11.89 | +0.96 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Apr 1, 2021 | 11.92 | +0.36 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Apr 2, 2021 | 11.77 | +0.50 ft | 2 | Possible | Chelsea Street |
| Apr 28, 2021 | 12.03 | +0.04 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Apr 29, 2021 | 12.62 | +0.55 ft | 12 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Apr 30, 2021 | 12.90 | +1.01 ft | 22 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 27, 2021 | 12.18 | ±0.00 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 28, 2021 | 12.10 | −0.04 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 29, 2021 | 12.07 | +0.18 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| May 30, 2021 | 12.02 | +0.58 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jun 22, 2021 | 12.11 | +0.54 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jun 23, 2021 | 11.94 | +0.08 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jun 24, 2021 | 11.88 | −0.09 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jun 26, 2021 | 11.92 | +0.03 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 21, 2021 | 12.00 | +0.74 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 22, 2021 | 12.15 | +0.71 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 23, 2021 | 12.15 | +0.63 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 25, 2021 | 12.21 | +0.74 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Jul 26, 2021 | 12.13 | +0.86 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 20, 2021 | 11.86 | +0.91 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 21, 2021 | 11.97 | +0.93 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 23, 2021 | 12.28 | +1.27 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Aug 24, 2021 | 12.04 | +1.20 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Oct 8, 2021 | 11.96 | +0.36 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Oct 9, 2021 | 11.96 | +0.29 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Oct 10, 2021 | 11.82 | +0.30 ft | 2 | Possible | Chelsea Street |
| Nov 5, 2021 | 12.18 | +0.27 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Nov 6, 2021 | 12.30 | +0.21 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Nov 7, 2021 | 12.25 | +0.23 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Nov 8, 2021 | 12.32 | +0.61 ft | 6 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Dec 4, 2021 | 11.83 | −0.24 ft | 2 | Possible | Chelsea Street |
| Dec 5, 2021 | 12.24 | +0.06 ft | 5 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Dec 6, 2021 | 12.41 | +0.38 ft | 8 | Likely | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |
| Dec 31, 2021 | 11.94 | +0.86 ft | 4 | Possible | Chelsea Street, William T. Morrissey Boulevard, Marginal Street |

[All Boston history](https://floodroute.com/ma/boston/history.md) · [Live forecast](https://floodroute.com/ma/boston.md)

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)

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