Water temperature in Monroe Harbor (IL) in April
Is it warm enough to swim in Monroe Harbor in April? Average water temperature in Monroe Harbor in April is 42.4°F and therefore is not suitable for comfortable swimming. The warmest water in Monroe Harbor in April is 50.4°F, and the coldest is 34.9°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Monroe Harbor
Changes water temperature in Monroe Harbor in April 2025, 2024
To get an accurate forecast for the water temperature in Monroe 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 Monroe Harbor, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of April.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| April 1 | 41.7°F | 41.2°F | 35.6°F | 43.5°F |
| April 2 | 41.5°F | 40.8°F | 34.9°F | 45.3°F |
| April 3 | 41.4°F | 40.5°F | 35.1°F | 44.4°F |
| April 4 | 42.1°F | 40.5°F | 35.2°F | 43.7°F |
| April 5 | 41.5°F | 41.2°F | 36.3°F | 43.9°F |
| April 6 | 43.2°F | 41.7°F | 36.5°F | 44.6°F |
| April 7 | 43.7°F | 41.9°F | 36.7°F | 44.4°F |
| April 8 | 42.1°F | 42.3°F | 36.5°F | 45.5°F |
| April 9 | 42.1°F | 42.3°F | 36.7°F | 45.1°F |
| April 10 | 41.9°F | 42.8°F | 36.9°F | 44.6°F |
| April 11 | 41.9°F | 42.4°F | 37.4°F | 44.8°F |
| April 12 | 42.6°F | 44.2°F | 38.3°F | 45.3°F |
| April 13 | 42.4°F | 44.6°F | 38.5°F | 45°F |
| April 14 | 43.9°F | 45.1°F | 38.5°F | 45.7°F |
| April 15 | 43.9°F | 46.9°F | 38.7°F | 46.9°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| April 16 | 44.8°F | 46.9°F | 38.8°F | 46.9°F |
| April 17 | 44.1°F | 46.8°F | 38.7°F | 46.8°F |
| April 18 | 43.7°F | 47.7°F | 39°F | 47.7°F |
| April 19 | 43.5°F | 47.7°F | 38.7°F | 47.7°F |
| April 20 | 45.1°F | 47.7°F | 39°F | 47.7°F |
| April 21 | 47.7°F | 48.4°F | 39.6°F | 48.4°F |
| April 22 | 47.1°F | 48.2°F | 39°F | 48.2°F |
| April 23 | 46.9°F | 49.6°F | 39.7°F | 49.6°F |
| April 24 | 46.4°F | 48.2°F | 40.6°F | 48.2°F |
| April 25 | 47.3°F | 45.5°F | 40.6°F | 48.2°F |
| April 26 | 47.7°F | 43.2°F | 41°F | 48.6°F |
| April 27 | 46.8°F | 43.5°F | 41.2°F | 48.4°F |
| April 28 | 48°F | 43.7°F | 42.1°F | 48°F |
| April 29 | 48.6°F | 45.3°F | 42.4°F | 48.9°F |
| April 30 | 50.4°F | 45.1°F | 42.8°F | 50.4°F |
Average water temperature in Monroe Harbor in April over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 42.6°F | 41.7°F | 38.8°F | 41.9°F | 42.3°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 45.1°F | 41.5°F | 43.5°F | 44.4°F | 44.4°F |
Monroe Harbor sea state in April
Chart comparing the height of waves in Monroe Harbor in April 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.
Monroe Harbor water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
