Does a high water-hardness rank mean the water is unsafe?

No. Hardness mainly describes dissolved calcium and magnesium and scale potential. It is not a drinking-water safety score or contaminant ranking.

US city water hardness ranking

Hardest-water cities in the US, ranked

This ranking starts with the highest qualifying city median rather than the single highest ZIP estimate. A city must have multiple readings and more than one supported estimate before it can appear.

Complete table

Top 100 qualifying cities

Data through Aug 18, 2026

Rank	City	Median	Class	Indexed range	Evidence	Supported
1	PascagoulaMS	2395 PPM140.1 GPG	Very Hard	2395–2400 PPM	3 ZIPs · 2 sites	100%High/Moderate
2	BiloxiMS	1885 PPM110.2 GPG	Very Hard	1870–2040 PPM	4 ZIPs · 2 sites	100%High/Moderate
3	GulfportMS	1805 PPM105.6 GPG	Very Hard	1740–1870 PPM	3 ZIPs · 2 sites	100%High/Moderate
4	FargoND	711 PPM41.6 GPG	Very Hard	705–716 PPM	4 ZIPs · 3 sites	100%High/Moderate
5	Rapid CitySD	615 PPM36 GPG	Very Hard	525.5–615 PPM	3 ZIPs · 3 sites	100%High/Moderate
6	BismarckND	503 PPM29.4 GPG	Very Hard	499.5–503 PPM	4 ZIPs · 2 sites	100%High/Moderate
7	IndependenceMO	470 PPM27.5 GPG	Very Hard	456–483 PPM	7 ZIPs · 3 sites	100%High/Moderate
8	San LuisAZ	449 PPM26.3 GPG	Very Hard	402–450 PPM	3 ZIPs · 2 sites	100%High/Moderate
9	OdessaTX	421 PPM24.6 GPG	Very Hard	369–420.5 PPM	3 ZIPs · 2 sites	100%High/Moderate
10	RichfieldWI	417 PPM24.4 GPG	Very Hard	411–417 PPM	3 ZIPs · 2 sites	100%High/Moderate
11	BakersfieldCA	405 PPM23.7 GPG	Very Hard	69.1–565 PPM	9 ZIPs · 3 sites	100%High/Moderate
12	RockfordIL	394 PPM23 GPG	Very Hard	373.5–396 PPM	8 ZIPs · 2 sites	100%High/Moderate
13	Las CrucesNM	388 PPM22.7 GPG	Very Hard	318–453 PPM	5 ZIPs · 4 sites	100%High/Moderate
14	Grand JunctionCO	382 PPM22.3 GPG	Very Hard	373–389 PPM	4 ZIPs · 3 sites	100%High/Moderate
15	ProvoUT	379 PPM22.2 GPG	Very Hard	336–423 PPM	4 ZIPs · 2 sites	100%High/Moderate
16	LansingMI	374 PPM21.9 GPG	Very Hard	373–375 PPM	6 ZIPs · 3 sites	100%High/Moderate
17	SpringfieldOH	369 PPM21.6 GPG	Very Hard	369–371 PPM	6 ZIPs · 4 sites	100%High/Moderate
18	LakelandFL	368 PPM21.5 GPG	Very Hard	363.5–371 PPM	6 ZIPs · 2 sites	100%High/Moderate
19	Battle CreekMI	359 PPM21 GPG	Very Hard	359–362 PPM	5 ZIPs · 2 sites	100%High/Moderate
20	ManhattanKS	359 PPM21 GPG	Very Hard	358.5–383 PPM	3 ZIPs · 2 sites	100%High/Moderate
21	OrlandoFL	357 PPM20.9 GPG	Very Hard	353–360 PPM	16 ZIPs · 2 sites	100%High/Moderate
22	St. CloudFL	357 PPM20.9 GPG	Very Hard	356–359 PPM	3 ZIPs · 2 sites	100%High/Moderate
23	Palm BayFL	355 PPM20.8 GPG	Very Hard	355–357 PPM	4 ZIPs · 2 sites	100%High/Moderate
24	WildwoodFL	353 PPM20.6 GPG	Very Hard	349–363.5 PPM	5 ZIPs · 2 sites	100%High/Moderate
25	DeltonaFL	353 PPM20.6 GPG	Very Hard	351–356.5 PPM	3 ZIPs · 2 sites	100%High/Moderate
26	ColumbiaMO	339 PPM19.8 GPG	Very Hard	328–347 PPM	5 ZIPs · 2 sites	100%High/Moderate
27	Brooklyn ParkMN	325 PPM19 GPG	Very Hard	324.5–324.5 PPM	4 ZIPs · 4 sites	100%High/Moderate
28	EdinaMN	322 PPM18.8 GPG	Very Hard	322–322 PPM	4 ZIPs · 2 sites	100%High/Moderate
29	EaganMN	320 PPM18.7 GPG	Very Hard	320–322 PPM	3 ZIPs · 2 sites	100%High/Moderate
30	NaplesFL	319 PPM18.7 GPG	Very Hard	319–319 PPM	6 ZIPs · 2 sites	100%High/Moderate
31	Bonita SpringsFL	319 PPM18.7 GPG	Very Hard	319–319 PPM	3 ZIPs · 2 sites	100%High/Moderate
32	Fort PierceFL	314 PPM18.4 GPG	Very Hard	305–314 PPM	5 ZIPs · 4 sites	100%High/Moderate
33	Lehigh AcresFL	313 PPM18.3 GPG	Very Hard	313–316 PPM	6 ZIPs · 3 sites	100%High/Moderate
34	Port St. LucieFL	302 PPM17.7 GPG	Very Hard	297–341 PPM	7 ZIPs · 4 sites	100%High/Moderate
35	ElkhartIN	295 PPM17.3 GPG	Very Hard	295–296.5 PPM	3 ZIPs · 2 sites	100%High/Moderate
36	MahometIL	295 PPM17.3 GPG	Very Hard	289–312 PPM	3 ZIPs · 3 sites	100%High/Moderate
37	RuidosoNM	288 PPM16.8 GPG	Very Hard	287.5–319 PPM	4 ZIPs · 3 sites	100%High/Moderate
38	Las VegasNV	287 PPM16.8 GPG	Very Hard	274–287 PPM	18 ZIPs · 2 sites	100%High/Moderate
39	HendersonNV	287 PPM16.8 GPG	Very Hard	274–287 PPM	9 ZIPs · 2 sites	100%High/Moderate
40	RochesterNY	286 PPM16.7 GPG	Very Hard	265.5–290 PPM	17 ZIPs · 2 sites	100%High/Moderate
41	West Palm BeachFL	285 PPM16.7 GPG	Very Hard	285–289 PPM	6 ZIPs · 4 sites	100%High/Moderate
42	DavenportIA	285 PPM16.7 GPG	Very Hard	285–285 PPM	6 ZIPs · 2 sites	83%High/Moderate
43	Delray BeachFL	284 PPM16.6 GPG	Very Hard	283–284 PPM	4 ZIPs · 2 sites	100%High/Moderate
44	Boynton BeachFL	284 PPM16.6 GPG	Very Hard	284–284 PPM	3 ZIPs · 2 sites	100%High/Moderate
45	Boca RatonFL	282 PPM16.5 GPG	Very Hard	281–283 PPM	7 ZIPs · 4 sites	100%High/Moderate
46	DavieFL	282 PPM16.5 GPG	Very Hard	280–282 PPM	4 ZIPs · 4 sites	100%High/Moderate
47	Pembroke PinesFL	282 PPM16.5 GPG	Very Hard	281–282 PPM	3 ZIPs · 3 sites	100%High/Moderate
48	PlantationFL	282 PPM16.5 GPG	Very Hard	281.5–282 PPM	3 ZIPs · 3 sites	100%High/Moderate
49	SunriseFL	282 PPM16.5 GPG	Very Hard	281.5–282 PPM	3 ZIPs · 3 sites	100%High/Moderate
50	WestonFL	282 PPM16.5 GPG	Very Hard	281–282 PPM	3 ZIPs · 3 sites	100%High/Moderate
51	MiramarFL	281 PPM16.4 GPG	Very Hard	280–282 PPM	4 ZIPs · 4 sites	100%High/Moderate
52	MiamiFL	280 PPM16.4 GPG	Very Hard	278–280 PPM	19 ZIPs · 4 sites	100%High/Moderate
53	Fort LauderdaleFL	280 PPM16.4 GPG	Very Hard	280–281 PPM	10 ZIPs · 4 sites	100%High/Moderate
54	HammondIN	280 PPM16.4 GPG	Very Hard	265–280 PPM	5 ZIPs · 2 sites	100%High/Moderate
55	HialeahFL	280 PPM16.4 GPG	Very Hard	280–282 PPM	4 ZIPs · 2 sites	100%High/Moderate
56	Pompano BeachFL	280 PPM16.4 GPG	Very Hard	280–281 PPM	4 ZIPs · 2 sites	100%High/Moderate
57	North MiamiFL	280 PPM16.4 GPG	Very Hard	280–280 PPM	3 ZIPs · 2 sites	100%High/Moderate
58	GainesvilleFL	277 PPM16.2 GPG	Very Hard	260.5–280 PPM	11 ZIPs · 2 sites	100%High/Moderate
59	South BendIN	276 PPM16.1 GPG	Very Hard	273–290.5 PPM	9 ZIPs · 2 sites	67%High/Moderate
60	Cedar RapidsIA	276 PPM16.1 GPG	Very Hard	276–285 PPM	6 ZIPs · 3 sites	100%High/Moderate
61	WaterlooIA	275 PPM16.1 GPG	Very Hard	269–274.5 PPM	3 ZIPs · 2 sites	100%High/Moderate
62	North Las VegasNV	274 PPM16 GPG	Very Hard	274–274 PPM	8 ZIPs · 2 sites	100%High/Moderate
63	Palo AltoCA	273 PPM16 GPG	Very Hard	273–273 PPM	4 ZIPs · 2 sites	100%High/Moderate
64	HomesteadFL	273 PPM16 GPG	Very Hard	272–277 PPM	3 ZIPs · 3 sites	100%High/Moderate
65	SunnyvaleCA	272 PPM15.9 GPG	Very Hard	272–273 PPM	4 ZIPs · 2 sites	100%High/Moderate
66	San JoseCA	271 PPM15.8 GPG	Very Hard	257–282.5 PPM	31 ZIPs · 9 sites	100%High/Moderate
67	StocktonCA	271 PPM15.8 GPG	Very Hard	254–290 PPM	11 ZIPs · 3 sites	100%High/Moderate
68	GaryIN	265 PPM15.5 GPG	Very Hard	265–280 PPM	7 ZIPs · 2 sites	100%High/Moderate
69	ModestoCA	257 PPM15 GPG	Very Hard	223–274 PPM	8 ZIPs · 2 sites	100%High/Moderate
70	OmahaNE	255 PPM14.9 GPG	Very Hard	255–255 PPM	31 ZIPs · 2 sites	100%High/Moderate
71	St. LouisMO	255 PPM14.9 GPG	Very Hard	254–256 PPM	19 ZIPs · 2 sites	100%High/Moderate
72	BellevueNE	255 PPM14.9 GPG	Very Hard	255–255 PPM	4 ZIPs · 2 sites	100%High/Moderate
73	HaywardCA	249 PPM14.6 GPG	Very Hard	249–251.5 PPM	4 ZIPs · 2 sites	100%High/Moderate
74	ChicagoIL	247 PPM14.4 GPG	Very Hard	243–265 PPM	57 ZIPs · 4 sites	100%High/Moderate
75	BuckeyeAZ	243 PPM14.2 GPG	Very Hard	243–243 PPM	5 ZIPs · 4 sites	100%High/Moderate
76	WaukeshaWI	242 PPM14.2 GPG	Very Hard	242–242 PPM	3 ZIPs · 2 sites	100%High/Moderate
77	JacksonvilleFL	238 PPM13.9 GPG	Very Hard	232.5–241.5 PPM	34 ZIPs · 4 sites	100%High/Moderate
78	AppletonWI	236 PPM13.8 GPG	Very Hard	235–289 PPM	4 ZIPs · 3 sites	100%High/Moderate
79	PuebloCO	232 PPM13.6 GPG	Very Hard	224–240 PPM	6 ZIPs · 6 sites	100%High/Moderate
80	MesaAZ	228 PPM13.3 GPG	Very Hard	211–228 PPM	14 ZIPs · 2 sites	100%High/Moderate
81	ScottsdaleAZ	228 PPM13.3 GPG	Very Hard	211–229 PPM	9 ZIPs · 3 sites	100%High/Moderate
82	TulsaOK	226 PPM13.2 GPG	Very Hard	130–235 PPM	25 ZIPs · 4 sites	76%High/Moderate
83	DowneyCA	215 PPM12.6 GPG	Very Hard	213–221.5 PPM	3 ZIPs · 2 sites	100%High/Moderate
84	WhittierCA	212 PPM12.4 GPG	Very Hard	210–213 PPM	4 ZIPs · 3 sites	100%High/Moderate
85	PhoenixAZ	211 PPM12.3 GPG	Very Hard	97–295 PPM	47 ZIPs · 10 sites	100%High/Moderate
86	LakewoodCA	211 PPM12.3 GPG	Very Hard	210.5–213 PPM	3 ZIPs · 2 sites	100%High/Moderate
87	Colorado SpringsCO	206 PPM12 GPG	Very Hard	108–218.5 PPM	25 ZIPs · 17 sites	100%High/Moderate
88	Wichita FallsTX	206 PPM12 GPG	Very Hard	206–252 PPM	6 ZIPs · 3 sites	100%High/Moderate
89	Santa RosaCA	193 PPM11.3 GPG	Very Hard	180–200 PPM	6 ZIPs · 4 sites	100%High/Moderate
90	MinneapolisMN	191 PPM11.2 GPG	Very Hard	180.5–191 PPM	21 ZIPs · 2 sites	100%High/Moderate
91	Huntington BeachCA	189 PPM11.1 GPG	Very Hard	189–189 PPM	5 ZIPs · 2 sites	100%High/Moderate
92	Santa MonicaCA	189 PPM11.1 GPG	Very Hard	178–189 PPM	5 ZIPs · 2 sites	80%High/Moderate
93	VallejoCA	189 PPM11.1 GPG	Very Hard	186–189 PPM	4 ZIPs · 4 sites	100%High/Moderate
94	FairfieldCA	189 PPM11.1 GPG	Very Hard	186–192 PPM	3 ZIPs · 2 sites	100%High/Moderate
95	GlendaleAZ	188 PPM11 GPG	Very Hard	97–187.5 PPM	9 ZIPs · 3 sites	100%High/Moderate
96	Garden GroveCA	188 PPM11 GPG	Very Hard	184–189 PPM	5 ZIPs · 2 sites	100%High/Moderate
97	HarrisonburgVA	187 PPM10.9 GPG	Very Hard	187–187 PPM	3 ZIPs · 2 sites	100%High/Moderate
98	JesupGA	186 PPM10.9 GPG	Very Hard	186–191 PPM	3 ZIPs · 3 sites	100%High/Moderate
99	San BernardinoCA	185 PPM10.8 GPG	Very Hard	182–186.5 PPM	9 ZIPs · 6 sites	100%High/Moderate
100	JacksonvilleNC	183 PPM10.7 GPG	Very Hard	183–183.5 PPM	6 ZIPs · 3 sites	100%High/Moderate

Ranking methodology

How this city ranking is calculated

We group ZIP profiles by city and state, then rank each city's median—not its maximum. To qualify, a city needs at least 3hardness readings, with at least 2labeled High or Moderate confidence and at least 2distinct monitoring sites. 209 cities meet that rule in the current dataset.

The qualification rule reduces single-estimate outliers but does not turn nearby environmental observations into household tap tests. Open any city to see observation distance, dates, utility associations, and its individual ZIP reports.

Quick answer

Which US city has the hardest qualifying water profile?

Pascagoula, MS is first in this ranking with a median indexed hardness of 2395 PPM (140.1 GPG), based on 3 ZIP readings.

That result describes this index and its current evidence rules. It should not be generalized to every address in the jurisdiction without checking the linked local profile.

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