Hardest Water in California

87 cities ranked by water hardness. Encinitas tops the list at 300 PPM.

California's water hardness varies significantly by city and water source. The state average across our database is 180 PPM, which is very hard. Most California households will benefit from a water softener. 85% of cities we track in California have hardness above 120 PPM.

Encinitas has the hardest water at 300 PPM (17.5 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. Sacramento has the softest water at just 18 PPM. No softener is needed.

#	City	PPM	GPG	Level	Softener?
1	Encinitas	300	17.5	Extremely Hard	Yes
2	Camarillo	280	16.4	Extremely Hard	Yes
3	Rancho Cucamonga South	280	16.4	Extremely Hard	Yes
4	Irvine South	280	16.4	Extremely Hard	Yes
5	Lake Forest	280	16.4	Extremely Hard	Yes
6	Rancho Santa Margarita	280	16.4	Extremely Hard	Yes
7	Gilroy	280	16.4	Extremely Hard	Yes
8	Irvine North	270	15.8	Extremely Hard	Yes
9	La Jolla	270	15.8	Extremely Hard	Yes
10	Lancaster	265	15.5	Extremely Hard	Yes
11	Anaheim Hills	260	15.2	Extremely Hard	Yes
12	Palmdale	250	14.6	Extremely Hard	Yes
13	Glendale	250	14.6	Extremely Hard	Yes
14	Simi Valley	250	14.6	Extremely Hard	Yes
15	La Mirada	240	14	Very Hard	Yes
16	Bell	230	13.5	Very Hard	Yes
17	Monterey	230	13.5	Very Hard	Yes
18	Sunnyvale	222	13	Very Hard	Yes
19	Temecula	220	12.9	Very Hard	Yes
20	Norwalk South	220	12.9	Very Hard	Yes
21	Chula Vista	216	12.6	Very Hard	Yes
22	Concord	215	12.6	Very Hard	Yes
23	Hayward	214	12.5	Very Hard	Yes
24	Carlsbad	210	12.3	Very Hard	Yes
25	Chatsworth	210	12.3	Very Hard	Yes
26	Fontana	208	12.2	Very Hard	Yes
27	Vista	205	12	Very Hard	Yes
28	Long Beach	204	11.9	Very Hard	Yes
29	Moreno Valley	204	11.9	Very Hard	Yes
30	Garden Grove	204	11.9	Very Hard	Yes
31	Torrance	203	11.9	Very Hard	Yes
32	San Marcos	202	11.8	Very Hard	Yes
33	Anaheim	201	11.8	Very Hard	Yes
34	Escondido	201	11.8	Very Hard	Yes
35	San Diego	200	11.7	Very Hard	Yes
36	Riverside	200	11.7	Very Hard	Yes
37	Corona	200	11.7	Very Hard	Yes
38	Woodland Hills	200	11.7	Very Hard	Yes
39	El Monte	198	11.6	Very Hard	Yes
40	West Covina	195	11.4	Very Hard	Yes
41	Fremont	192	11.2	Very Hard	Yes
42	Rancho Cucamonga	192	11.2	Very Hard	Yes
43	Norwalk	192	11.2	Very Hard	Yes
44	San Bernardino	190	11.1	Very Hard	Yes
45	Downey	190	11.1	Very Hard	Yes
46	Carson	190	11.1	Very Hard	Yes
47	Valencia	190	11.1	Very Hard	Yes
48	Huntington Beach	189	11.1	Very Hard	Yes
49	Santa Clarita	188	11	Very Hard	Yes
50	South Gate	185	10.8	Very Hard	Yes
51	San Jose	183	10.7	Very Hard	Yes
52	Ontario	183	10.7	Very Hard	Yes
53	Pasadena	182	10.6	Very Hard	Yes
54	Los Angeles	180	10.5	Very Hard	Yes
55	Pomona	180	10.5	Very Hard	Yes
56	Gardena	180	10.5	Very Hard	Yes
57	Torrance South	180	10.5	Very Hard	Yes
58	Redondo Beach	180	10.5	Very Hard	Yes
59	Santa Ana	178	10.4	Hard	Recommended
60	Murrieta	177	10.4	Hard	Recommended
61	Oxnard	175	10.2	Hard	Recommended
62	Santa Maria	175	10.2	Hard	Recommended
63	Irvine	173	10.1	Hard	Recommended
64	Roseville	169	9.9	Hard	Recommended
65	Elk Grove	154	9	Hard	Recommended
66	Modesto	144	8.4	Hard	Recommended
67	Visalia	141	8.2	Hard	Recommended
68	Turlock	140	8.2	Hard	Recommended
69	Manteca	135	7.9	Hard	Recommended
70	Bakersfield	132	7.7	Hard	Recommended
71	Fresno North	130	7.6	Hard	Recommended
72	Milpitas	130	7.6	Hard	Recommended
73	Stockton	129	7.5	Hard	Recommended
74	Fresno	126	7.4	Hard	Recommended
75	Vacaville	110	6.4	Moderately Hard	Optional
76	Newark	90	5.3	Moderately Hard	Optional
77	Santa Cruz Downtown	70	4.1	Moderately Hard	Optional
78	Santa Rosa	60	3.5	Moderately Hard	Optional
79	Dublin	60	3.5	Moderately Hard	Optional
80	Napa	45	2.6	Slightly Hard	No
81	Oakland	40	2.3	Slightly Hard	No
82	Redding	35	2	Slightly Hard	No
83	Folsom	35	2	Slightly Hard	No
84	Daly City	34	2	Slightly Hard	No
85	Santa Cruz	28	1.6	Slightly Hard	No
86	San Francisco	21	1.2	Slightly Hard	No
87	Sacramento	18	1.1	Slightly Hard	No

Frequently Asked Questions

What is the average water hardness in California?

Across 87 cities in our database, the average water hardness in California is 180 PPM (10.5 GPG). This ranges from 18 PPM in Sacramento to 300 PPM in Encinitas.

Do I need a water softener in California?

It depends on your city. 85% of California cities in our database (74 of 87) have hardness above 120 PPM where a softener provides measurable benefit. Check your specific city above.

Which California city has the softest water?

Sacramento has the softest water in California at 18 PPM (1.1 GPG). No water softener is needed at this level.

What causes hard water in California?

Hard water in California 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.