Hardest Water in Wisconsin
17 cities ranked by water hardness. Madison tops the list at 312 PPM.
Wisconsin's water hardness varies significantly by city and water source. The state average across our database is 210 PPM, which is very hard. Most Wisconsin households will benefit from a water softener. 100% of cities we track in Wisconsin have hardness above 120 PPM.
Madison has the hardest water at 312 PPM (18.2 GPG). At this level, expect visible scale on faucets, reduced water heater efficiency, and higher soap usage. A salt-based water softener typically pays for itself within 12-18 months in energy and consumable savings.
| # | City | PPM | GPG | Level | Softener? |
|---|---|---|---|---|---|
| 1 | Madison | 312 | 18.2 | Extremely Hard | Yes |
| 2 | Appleton | 304 | 17.8 | Extremely Hard | Yes |
| 3 | Fond du Lac | 290 | 17 | Extremely Hard | Yes |
| 4 | Janesville | 280 | 16.4 | Extremely Hard | Yes |
| 5 | Eau Claire | 265 | 15.5 | Extremely Hard | Yes |
| 6 | Oshkosh | 256 | 15 | Extremely Hard | Yes |
| 7 | La Crosse | 235 | 13.7 | Very Hard | Yes |
| 8 | Waukesha | 196 | 11.5 | Very Hard | Yes |
| 9 | Brookfield | 190 | 11.1 | Very Hard | Yes |
| 10 | Stevens Point | 175 | 10.2 | Hard | Recommended |
| 11 | Sheboygan | 170 | 9.9 | Hard | Recommended |
| 12 | Green Bay | 166 | 9.7 | Hard | Recommended |
| 13 | Manitowoc | 165 | 9.6 | Hard | Recommended |
| 14 | Kenosha | 143 | 8.4 | Hard | Recommended |
| 15 | Milwaukee | 140 | 8.2 | Hard | Recommended |
| 16 | Wauwatosa | 140 | 8.2 | Hard | Recommended |
| 17 | Racine | 139 | 8.1 | Hard | Recommended |
Frequently Asked Questions
What is the average water hardness in Wisconsin?
Across 17 cities in our database, the average water hardness in Wisconsin is 210 PPM (12.3 GPG). This ranges from 139 PPM in Racine to 312 PPM in Madison.
Do I need a water softener in Wisconsin?
It depends on your city. 100% of Wisconsin cities in our database (17 of 17) have hardness above 120 PPM where a softener provides measurable benefit. Check your specific city above.
Which Wisconsin city has the softest water?
Racine has the softest water in Wisconsin at 139 PPM (8.1 GPG). No water softener is needed at this level.
What causes hard water in Wisconsin?
Hard water in Wisconsin is caused by dissolved calcium and magnesium from the local geology. Limestone and dolomite bedrock are the primary sources, dissolving minerals into groundwater and surface water as it flows through the rock.