Window Washing in Minneapolis
Minneapolis hardness moves from 83 to 106 mg/L through the seasons, and water leaves the plant at pH 9.06, alkaline enough to punish too much soap.
Minneapolis water is moderately hard, enough to mark a pane that dries slowly but not enough to need treated rinse water; the bigger point is that it leaves the plant strongly alkaline, so go light on soap. The season is short: spring books up fast with everyone wanting the winter's salt off, and July to September brings the most reliable weather, when a single-story exterior runs $300 to $550.
What the water means for the glass
Somewhere between 83 and 106 mg/L is moderately hard — enough to leave a mark on a pane that dries slowly, not enough to demand treated rinse water on ordinary residential work. The more useful reading is the pH. Finished water near 9 is alkaline, and alkaline water that dries on glass leaves a film that a second plain-water pass will not lift. Work wet, clear fully, and keep detergent dosing light, because the supply is already doing part of that job for you.
Minneapolis tap water, by the numbers
| Hardness | 83–106 mg/L as CaCO₃ 4.9 to 6.2 grains per gallon, printed by the city beside the mg/L figures, as published by Minneapolis Water Works. |
|---|---|
| pH | 9.06 |
| Alkalinity | 57 mg/L as CaCO₃ |
| Iron | not detected |
| Manganese | < 0.01 mg/L |
| Sodium | 14.9 mg/L |
| Chloride | 28.1 mg/L |
| Total dissolved solids | 153 mg/L |
| Disinfectant | chloramine |
| Source and treatment | The Mississippi River at Fridley, drawn from just below the Interstate 694 crossing, serving Minneapolis and seven suburbs · Debris screening at the raw-water intakes, potassium permanganate during taste-and-odour episodes, then lime softening at the Fridley Softening Plant. Softened water goes either to the Fridley Filter Plant's dual granular-media filters or to the Columbia Heights ultrafiltration membrane plant. Chlorine and ammonia are dosed to form combined chloramines, and the chloramine residual is trimmed after filtration. · The plant softens. |
Not in the report: corrosion index.
SOURCE · Minneapolis Water Works, Monthly Plant Effluent Water Analysis for May 2025, 'Physical and Chemical Water Quality' and 'Chemical Water Quality' tables (minneapolismn.gov). Treatment description from the City of Minneapolis 2040 comprehensive plan water-system appendix and the Minnesota Department of Health Waterline account of the Columbia Heights ultrafiltration plant. · How we source these numbers
When a wash holds
What sets the cleaning clock
Winter dominates. Road salt and grit reach street-level and low residential glazing from the first application to the last thaw, and spring is the heaviest single clean of the year because it clears months of accumulation at once. Leaf cast peaks in October under the elms and oaks. High summer is the easy season, when water is warm, evaporation is manageable and the only real load is dust and pollen. Sub-freezing weeks close outdoor work entirely rather than merely slowing it.
MINNESOTA SEASON BY SEASON →What's specific to Minneapolis
Minneapolis is unusual on this site because it publishes its water chemistry every month, so the seasonal movement is on the record rather than assumed. Total hardness across 2024 plant analyses ran 83 mg/L in October, 91 in July and 106 in December — 4.9 to 6.2 grains — which is moderately hard water with a real winter-to-autumn swing. The supply is lime-softened Mississippi River water and the treatment shows: pH around 9.06 and magnesium far below calcium, neither of which raw river water would give. That high pH matters more for glass than the hardness does, because alkaline water left standing does not dry clean and it compounds rather than cancels an alkaline detergent. Chloramine at around 4 ppm persists in bucket water. And the river runs from 2.8°C in December to 27.2°C in July, which makes winter tap water a working constraint in itself.
Minneapolis publishes its water chemistry monthly rather than annually, which makes it one of the few cities on this site where seasonal movement in the supply is visible rather than inferred. Successive 2024 plant-effluent analyses recorded total hardness at 83 mg/L in October, 91 in July and 106 in December — 4.9, 5.3 and 6.2 grains per gallon.
That spread is the useful part. A single annual figure would describe none of those months well, and the movement is large enough to matter: at the December end, deposit on a cold pane appears noticeably sooner than it does in autumn.
The finished water is deliberately softened, and the treatment leaves fingerprints all over the published numbers. Plant pH runs around 9.06, and magnesium sits at 4.4 to 6.2 mg/L against calcium of 28 to 35 — a magnesium-to-calcium ratio far lower than raw river water carries, which is what a lime-softening train does to Mississippi water.
High pH is its own consideration on glass. Water leaving the plant at pH 9.06 is alkaline enough that it does not want to be left standing on a pane to dry, and it interacts with alkaline detergents rather than neutralising them, so over-soaping shows up faster here than the modest hardness figure would predict.
The city disinfects with chloramine rather than free chlorine, holding a total residual around 4.0 to 4.2 ppm. Chloramine is more persistent than chlorine, which is why the smell lingers in bucket water left standing through a job.
River temperature is recorded alongside everything else and the annual swing is extreme: 2.8 degrees Celsius in December against 27.2 in July. Winter tap water in Minneapolis arrives close to freezing, which is a genuine working constraint rather than a comfort issue — it stiffens rubber, slows evaporation to a crawl and will freeze on the glass in the wrong conditions.
Dissolved solids of 153 mg/L with chloride at 28.1 mg/L complete the picture. Chloride at that level in an upper-Midwest river is a winter road-salt signature, and it is a reminder that what the river carries in spring is not what it carried in August.
How old the glass is
- Before 1940 · 43%wood sash and older glass
- 1940–1959 · 14%steel casements, early aluminium
- 1960–1979 · 15%aluminium sliders, often single-pane
- 1980–1999 · 10%double-pane units become standard
- 2000–2009 · 6%vinyl frames, low-E spreading
- 2010 or later · 11%low-E common: gentle cleaners only
The city, by neighborhood
What window cleaning costs in Minneapolis
A short season is the defining economic fact. Demand compresses into spring and summer, and spring is oversubscribed because everyone wants the winter's salt off at once, which firms prices in exactly the weeks a crew has least slack. Heritage glazing on the hill carries a skill premium. Converted warehouse frontage in the northeast prices on access equipment rather than pane count.
Doing it yourself
Between roughly May and October this is ordinary homeowner work, and the water asks nothing special of it. The obstacles are the seasons and the stock: the hill districts carry leaded and stained panels that should not meet a standard blade at all, and the converted industrial buildings in the northeast have factory glazing at heights and in frames that no domestic ladder reaches sensibly. Winter work is a professional decision because freezing water on glass is a hazard before it is a finish problem.
OPEN COST ESTIMATOR →2025 annual mean at the City of Lakes Building monitor, 309 2nd Ave. S., 1.8 km north of the city (EPA site 27-053-0966).
2025 annual mean at the Near Road I-35/I-94 monitor, 1444 E 18th St, 1.1 km east of the city (EPA site 27-053-0962).
Largest air release: Interplastic Corp, 2015 NE Broadway ST (chemicals), inside the city limits, 10,364 lb in 2024.
Minneapolis can shut off water it finds being misused or wasted in ways that harm public health, safety or welfare. During an emergency over short supply or falling pressure in the city mains, nobody may draw city water except as the emergency declaration allows.
Minneapolis Code §509.1100: shut off for public interest, misuse, waste, or violation · Minneapolis Code §509.1400: water use limited during emergency period · checked September 2026
Minneapolis bans discharging non-stormwater into its storm sewer system, naming sewage, wastewater, contact cooling water and contaminated groundwater or surface water. The only exceptions are discharges under an approved industrial NPDES permit and water from fighting fires.
Minneapolis Code §54.140: prohibited discharges to storm sewer system · checked September 2026
Since a November 2025 rewrite of its heritage preservation chapter, Minneapolis gives the planning director and the Heritage Preservation Commission authority to approve or deny every proposed alteration to a landmark or to a property in a historic district. Buildings under interim protection as potential landmarks are covered too.
Minneapolis Code §599.1000: historic design review, description · checked September 2026
What actually shows up on Minneapolis glass
Most relevant on commercial interior glass — building-entry storefronts collect salt-tracked residue on lower thirds throughout the winter. Twice-monthly cleaning sufficient with normal wash protocol.
Minneapolis, answered
How hard is the water in Minneapolis, Minnesota?＋
Somewhere between 83 and 106 mg/L is moderately hard — enough to leave a mark on a pane that dries slowly, not enough to demand treated rinse water on ordinary residential work. The more useful reading is the pH.
How much does window cleaning cost in Minneapolis?＋
Residential window cleaning in Minneapolis typically runs $10–16 per pane or $300–550 for a standard single-story exterior. A short season is the defining economic fact. Demand compresses into spring and summer, and spring is oversubscribed because everyone wants the winter's salt off at once, which firms prices in exactly the weeks a crew has least slack.
When is the best time of year to clean windows in Minneapolis?＋
Minneapolis's drier, frost-free months are July to September, by NOAA's 1991–2020 normals for the Minneapolis/st Paul Airport station, where May brings the most rain. The calendar on this page marks July (after the May 11 bloom and after smoke season). Frost nights usually run from October 18 to April 23.
Can I rinse windows with Minneapolis tap water?＋
Yes, if the rinse is squeegeed off before it dries: Minneapolis Water Works publishes dissolved solids of 153 mg/L, between this site's two dissolved-solids flags. It draws on the Mississippi River at Fridley, drawn from just below the Interstate 694 crossing, serving Minneapolis and seven suburbs.
Why do my windows look dirty so quickly in Minneapolis?＋
In Minneapolis the dominant residue patterns include published hardness moving seasonally from 83 to 106 mg/l across successive monthly plant analyses and finished water leaving the plant at ph 9.06, alkaline enough to punish over-soaping. Winter dominates.
Do I need a professional to clean my windows in Minneapolis?＋
Between roughly May and October this is ordinary homeowner work, and the water asks nothing special of it. The obstacles are the seasons and the stock: the hill districts carry leaded and stained panels that should not meet a standard blade at all, and the converted industrial buildings in the northeast have factory glazing at heights and in frames that no domestic ladder…
What sets Downtown and the North Loop apart for window cleaning in Minneapolis?＋
High-rise curtain wall beside converted warehouse and milling stock, much of it heavy timber with original industrial sash. Two entirely different glazing problems inside four blocks of each other. Lowry Hill and Kenwood and Linden Hills have their own housing stock and glazing as well.
Other cities we cover in Minnesota
Nearby cities in neighboring states
Just over the Minnesota line