Water temperature in Winthrop Harbor (IL) in March
Is it warm enough to swim in Winthrop Harbor in March? Average water temperature in Winthrop Harbor in March is 35.8°F and therefore is not suitable for comfortable swimming. The warmest water in Winthrop Harbor in March is 44.2°F, and the coldest is 31.5°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Winthrop Harbor
Changes water temperature in Winthrop Harbor in March 2026, 2025
To get an accurate forecast for the water temperature in Winthrop Harbor for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Winthrop Harbor, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of March.
You can choose any other years:
| Day | 2026 | 2025 | Min | Max |
|---|---|---|---|---|
| March 1 | 33.6°F | 33.8°F | 31.5°F | 37.4°F |
| March 2 | 33.8°F | 33.6°F | 31.6°F | 37.2°F |
| March 3 | 33.8°F | 33.6°F | 31.5°F | 37.4°F |
| March 4 | 33.8°F | 33.8°F | 31.5°F | 38.8°F |
| March 5 | 34.3°F | 33.8°F | 31.6°F | 38.5°F |
| March 6 | 35.6°F | 35.2°F | 31.5°F | 37.9°F |
| March 7 | 35.2°F | 35.1°F | 31.8°F | 37.4°F |
| March 8 | 35.1°F | 34.7°F | 31.8°F | 37°F |
| March 9 | 36.3°F | 35.2°F | 31.8°F | 38.1°F |
| March 10 | 36.3°F | 35.2°F | 33.8°F | 37.9°F |
| March 11 | 34.5°F | 33.4°F | 38.8°F | |
| March 12 | 35.2°F | 32°F | 38.5°F | |
| March 13 | 36°F | 32°F | 38.8°F | |
| March 14 | 37.8°F | 32.9°F | 39°F | |
| March 15 | 37.6°F | 32.9°F | 44.2°F |
| Day | 2026 | 2025 | Min | Max |
|---|---|---|---|---|
| March 16 | 38.1°F | 31.5°F | 43.5°F | |
| March 17 | 37.4°F | 32.2°F | 39.2°F | |
| March 18 | 37.9°F | 33.3°F | 40.1°F | |
| March 19 | 37.6°F | 33.3°F | 40.1°F | |
| March 20 | 37.4°F | 33.1°F | 40.1°F | |
| March 21 | 37°F | 33.1°F | 41.2°F | |
| March 22 | 37.9°F | 33.1°F | 40.6°F | |
| March 23 | 36.1°F | 32.5°F | 40.6°F | |
| March 24 | 37°F | 32.4°F | 40.3°F | |
| March 25 | 37°F | 32.5°F | 43.2°F | |
| March 26 | 37.4°F | 33.6°F | 40.5°F | |
| March 27 | 37.4°F | 33.8°F | 43°F | |
| March 28 | 37.6°F | 33.8°F | 40.1°F | |
| March 29 | 36.5°F | 32.9°F | 40.3°F | |
| March 30 | 37.6°F | 33.1°F | 39.9°F | |
| March 31 | 38.8°F | 33.6°F | 39.4°F |
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Average water temperature in Winthrop Harbor in March over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 36°F | 36.7°F | 35.4°F | 34.3°F | 36.5°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 36.5°F | 35.1°F | 36.1°F | 38.5°F | 36.3°F |
Winthrop Harbor sea state in March
Chart comparing the height of waves in Winthrop Harbor in March over the past years. The red line indicates the height of the waves when swimming in the sea is prohibited. To view the current sea conditions, click on the graph.
Winthrop Harbor water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
