Water Hardness by State: All 50 States Ranked
Water hardness varies dramatically across the United States, from nearly mineral-free surface water in the Pacific Northwest and New England to extremely hard groundwater in the Great Plains and Desert Southwest. This ranking shows the average water hardness for each state based on data from major municipal water systems. Click any state to see city-level data, water sources, and treatment recommendations.
All States Ranked by Water Hardness
The table below ranks every US state and the District of Columbia by average water hardness in parts per million (ppm). Hardness levels are color-coded from green (soft) through red (very hard). States with harder water typically overlie limestone bedrock or rely heavily on deep well groundwater, while states with softer water tend to source from surface reservoirs, rivers, or regions with granite geology.
| # | State | Avg Hardness (PPM) | Hardness Level | Cities in Database |
|---|---|---|---|---|
| 1 | New Mexico (NM) | 350 ppm | Very Hard | 8 |
| 2 | Kansas (KS) | 300 ppm | Very Hard | 8 |
| 3 | Utah (UT) | 290 ppm | Very Hard | 9 |
| 4 | Indiana (IN) | 280 ppm | Very Hard | 8 |
| 5 | Arizona (AZ) | 270 ppm | Very Hard | 10 |
| 6 | Nebraska (NE) | 250 ppm | Hard | 8 |
| 7 | North Dakota (ND) | 250 ppm | Hard | 8 |
| 8 | South Dakota (SD) | 250 ppm | Hard | 8 |
| 9 | Iowa (IA) | 240 ppm | Hard | 8 |
| 10 | Nevada (NV) | 240 ppm | Hard | 8 |
| 11 | Wisconsin (WI) | 240 ppm | Hard | 10 |
| 12 | Texas (TX) | 230 ppm | Hard | 11 |
| 13 | Florida (FL) | 220 ppm | Hard | 11 |
| 14 | Minnesota (MN) | 210 ppm | Hard | 9 |
| 15 | California (CA) | 200 ppm | Hard | 11 |
| 16 | Illinois (IL) | 200 ppm | Hard | 10 |
| 17 | Wyoming (WY) | 190 ppm | Hard | 8 |
| 18 | Montana (MT) | 180 ppm | Moderately Hard | 8 |
| 19 | Colorado (CO) | 170 ppm | Moderately Hard | 9 |
| 20 | Idaho (ID) | 170 ppm | Moderately Hard | 8 |
| 21 | Oklahoma (OK) | 170 ppm | Moderately Hard | 8 |
| 22 | Missouri (MO) | 160 ppm | Moderately Hard | 8 |
| 23 | Ohio (OH) | 160 ppm | Moderately Hard | 9 |
| 24 | Michigan (MI) | 150 ppm | Moderately Hard | 9 |
| 25 | Pennsylvania (PA) | 140 ppm | Moderately Hard | 8 |
| 26 | Kentucky (KY) | 130 ppm | Moderately Hard | 8 |
| 27 | District of Columbia (DC) | 120 ppm | Slightly Hard | 7 |
| 28 | New Jersey (NJ) | 120 ppm | Slightly Hard | 8 |
| 29 | West Virginia (WV) | 120 ppm | Slightly Hard | 8 |
| 30 | Maryland (MD) | 115 ppm | Slightly Hard | 7 |
| 31 | Delaware (DE) | 110 ppm | Slightly Hard | 7 |
| 32 | Tennessee (TN) | 110 ppm | Slightly Hard | 8 |
| 33 | Louisiana (LA) | 105 ppm | Slightly Hard | 8 |
| 34 | Alabama (AL) | 100 ppm | Slightly Hard | 8 |
| 35 | Virginia (VA) | 85 ppm | Slightly Hard | 9 |
| 36 | Mississippi (MS) | 80 ppm | Slightly Hard | 8 |
| 37 | Georgia (GA) | 75 ppm | Slightly Hard | 9 |
| 38 | Alaska (AK) | 65 ppm | Slightly Hard | 7 |
| 39 | New York (NY) | 65 ppm | Slightly Hard | 10 |
| 40 | North Carolina (NC) | 60 ppm | Soft | 9 |
| 41 | Arkansas (AR) | 55 ppm | Soft | 8 |
| 42 | South Carolina (SC) | 50 ppm | Soft | 8 |
| 43 | Hawaii (HI) | 40 ppm | Soft | 8 |
| 44 | Connecticut (CT) | 35 ppm | Soft | 8 |
| 45 | Oregon (OR) | 30 ppm | Soft | 8 |
| 46 | Rhode Island (RI) | 30 ppm | Soft | 8 |
| 47 | Washington (WA) | 25 ppm | Soft | 8 |
| 48 | Massachusetts (MA) | 20 ppm | Soft | 8 |
| 49 | Vermont (VT) | 20 ppm | Soft | 8 |
| 50 | Maine (ME) | 15 ppm | Soft | 7 |
| 51 | New Hampshire (NH) | 15 ppm | Soft | 8 |
Regional Water Hardness Patterns
The Hard Water Belt: Great Plains and Desert Southwest
The hardest water in the United States is concentrated in a broad swath running from Texas and New Mexico northward through Kansas, Nebraska, and the Dakotas, and westward through Arizona, Utah, and Nevada. This region sits atop massive limestone and dolomite formations that dissolve calcium and magnesium into groundwater over millennia. Cities like Carlsbad, New Mexico (580 ppm), Roswell, New Mexico (520 ppm), and Dodge City, Kansas (480 ppm) regularly record some of the hardest municipal water in the nation. Homeowners in these areas almost universally benefit from water softener installation.
The Soft Water Coasts: New England and Pacific Northwest
The softest water in the country is found in New England (Maine, New Hampshire, Vermont, Massachusetts) and the Pacific Northwest (Oregon, Washington). These regions share two advantages: their geology features granite, basalt, and other hard rocks that resist mineral dissolution, and their water systems draw primarily from surface sources — mountain reservoirs, rivers, and protected watersheds. Portland, Oregon (10 ppm), Tacoma, Washington (15 ppm), and Portland, Maine (10 ppm) all deliver exceptionally soft water that requires no treatment. Residents in these areas rarely need water softeners and enjoy naturally great water quality.
The Variable Middle: Great Lakes and Southeast
States in the Great Lakes region (Michigan, Wisconsin, Minnesota, Ohio, Indiana) show the widest variation in water hardness. Cities drawing from the Great Lakes themselves tend to have moderate hardness (100-150 ppm), while inland cities relying on deep wells often have very hard water (250-350 ppm). The Southeast generally has softer water thanks to surface water sources and sandier soils, though Florida is a notable exception — its limestone aquifer produces some of the hardest water east of the Mississippi, with Jacksonville at 280 ppm and Naples at 350 ppm.
About This Data
Water hardness values in our database are based on annual water quality reports (Consumer Confidence Reports) published by municipal water utilities, supplemented by data from the USGS National Water Quality Assessment Program. State averages are weighted approximations based on the major metropolitan areas in each state. Individual city values represent the typical hardness level reported by the primary water utility serving that city.
Actual water hardness at your tap may differ from these averages due to seasonal variation, blending of water sources, the age and composition of your home's plumbing, and whether your utility adjusts hardness through treatment. For the most accurate reading, we recommend testing your tap water directly using a home test kit or requesting a current water quality report from your local utility. Use our lookup tool to find your city and see detailed water quality information including water source, pH, total dissolved solids, and treatment recommendations.