Window Washing Guide
GUIDE / WATER ATLAS / MISSISSIPPI
WATER ATLAS · SOUTHEAST

Water hardness in Mississippi

PLANNING RANGE
80–340 mg/L
4.7–19.9 grains/gal
BANDS SPANNED
Moderately Hard → Extremely Hard
DOMINANT SOURCE
Blended surface and groundwater

Mississippi runs as four working zones along a north-south axis. The DeSoto County corridor (Southaven, Olive Branch, Hernando) draws on the Memphis Sand aquifer, continuous with the Memphis profile across the state line. Jackson metro and central Mississippi run Pearl River-source surface and well-supplemented systems. The Delta agricultural belt (Greenwood, Cleveland, Greenville, Clarksdale) is well-water on most rural systems. On the Gulf Coast corridor (Biloxi, Gulfport, Pascagoula, Ocean Springs, Bay St. Louis) the open-Gulf salt-aerosol overlay matters more than the tap.

HOW IT BREAKS DOWNnot published

DeSoto County Memphis-Sand-aquifer profile is operationally continuous with Memphis Midtown — same chemistry, same delta-humidity production-window squeeze, same April-June and September-October practical high-production calendar. Jackson Pearl River-source supply publishes no hardness figure the site uses and carries substantial industrial-organic load on the lower Pearl. Delta rural well-water on the worst-affected systems with sub-micron suspended particulate. Gulf Coast salt-aerosol stack converges with the Alabama Mobile and Louisiana North Shore profiles. Pine pollen wave statewide late February through early May, peaking late March in the southern half. Tropical-humidity squeeze from mid-June through mid-September is the heaviest operating constraint statewide.

A blended system means hardness moves with the blend. Two addresses on the same utility can read differently, and the same address can read differently across a year, depending on which source is carrying the load that season.

What that means for the glass

Mississippi spans 4 hardness bands, which means there is no single answer for the whole state — the method changes as you move across it. Both ends are below.

Moderately HardSOFT END

61–120 mg/L

Tap water is still fine for most residential glass, with two exceptions worth knowing. Dark glass shows a faint mineral haze that lighter glass hides, and glass that is hot enough to flash the water off before you pull the squeegee will spot regardless of how soft the supply is. On both, a distilled final rinse costs about a dollar a window and removes the variable entirely. Everywhere else at this level, the water is not what is wrong.

HardMIDDLE

121–180 mg/L

This is the band where the water starts writing on the glass. Wash with tap — the surfactant holds the minerals in suspension while you work, so the wash pass is not the problem — then rinse with distilled and pull that. The rinse is the whole intervention: it replaces the mineral-bearing water sitting on the glass with water that has nothing in it to leave. This single change resolves most of the "I cleaned it and it still looks bad" complaints in this range, and it does not require buying a system.

Very HardMIDDLE

181–250 mg/L

A distilled rinse stops being an improvement and becomes the method. Tap water left to dry on glass at this concentration deposits a visible film within minutes, and the film is cumulative: each cleaning that ends in tap water adds a layer that the next cleaning has to get through first. Glass on a sprinkler line or under a runoff drip needs a maintenance interval, not just a better wash — the deposit is arriving faster than a cleaning schedule built around dust would predict.

Extremely HardHARD END

251+ mg/L

The hardest water in North America — Phoenix, Las Vegas, West Texas, much of the limestone Midwest. At this concentration calcium carbonate precipitates out of any water that touches the glass and dries, so what you are looking at is essentially limestone, growing one molecular layer at a time. Tap water cannot be part of the final pass under any circumstance, including "just a quick rinse." Above roughly 300 mg/L, buying distilled by the gallon stops making economic sense against a DI filter or a pure-water pole system, and a residential owner cleaning their own glass twice a year is usually better served by a service that already owns one.

By city

Hardest first — the order that matters, because the hard end is where the method has to change. Each figure is the named utility's own published number; cities whose utility publishes none are listed after them, without a band.

CITY / UTILITYBANDMG/L
BiloxiCity of Biloxi Public Works (four separate water systems) · groundwater—not published
GulfportCity of Gulfport Water (Pascagoula and Graham Ferry aquifer wells) · aquifer—not published
Hattiesburgthe City of Hattiesburg · groundwater—not published
JacksonJXN Water (City of Jackson system) · blended surface and groundwater—not published
MeridianMeridian Water and Sewer · blended surface and groundwater—not sourced
Olive BranchOlive Branch Water · aquifer—not sourced
Southaventhe City of Southaven · aquifer—not published
TupeloTupelo Water and Light · blended surface and groundwater—not sourced

Against all 271 covered cities

Where Mississippi's city pages sit in the national city rankings: hardness rank out of 185 cities whose utility publishes a figure, dissolved-solids rank out of 100, the disinfectant each utility reports, and the months each city's cleaning calendar marks for a wash. Rank 1 is the hardest or most mineral-heavy. 1 of these 5 cities use chloramine.

CITYHARDNESS RANKTDS RANKDISINFECTANTWASH IN
Biloxinot rankednot rankedfree chlorineMar, Oct, Nov
Gulfportnot rankednot rankedfree chlorineMar, Oct, Nov
Hattiesburgnot rankednot rankedfree chlorineApr, Sep, Oct
Jacksonnot rankednot rankedchloramineApr, Sep, Oct
Southavennot rankednot rankedfree chlorineJun

This page is about Mississippi's water and nothing else. For how cleaning actually works in Mississippi across the year — climate, seasonal timing, the local contaminants, the housing stock — see the Mississippi cleaning guide.

For a figure at your own address rather than your city, the Hard Water Scorer takes a ZIP code. If you run a pure-water system, the TDS diagnostic reads the other end of the same problem.

Nearby in the Southeast

Georgia
31.2–33.4 mg/L
North Carolina
5.52–62 mg/L
South Carolina
18–56 mg/L
Alabama
4–156 mg/L

Where these numbers come from

Each covered city utility's own published figure, taken from its most recent annual water quality report (Consumer Confidence Report) or its water-quality page, read in 2026. A city figure is the one its utility publishes for the service area, as a single number or the range it reports; it is not a reading from any one tap. A state range runs from the lowest to the highest figure published by the utilities we cover in that state, so it brackets those cities rather than describing an average resident. A state where no covered utility publishes a figure shows a planning estimate, labelled as one.

Private wells are outside all of it. A well is whatever the rock under it says, and the only number that describes one is a test of that tap. Have a reading that disagrees with this table? Send it to us — a number that contradicts the table is worth more than one that confirms it.