California water hardness varies depending on the region.

In general, the water in California tends to be hard, with higher levels of minerals such as calcium and magnesium.

According to the US Geological Survey, the water hardness in California ranges from less than 50 mg/L to more than 500 mg/L, with most areas falling in the range of 100-300 mg/L.

The hardest water in California is typically found in the southern part of the state, particularly in areas such as San Diego, Orange County, and Riverside County.

It’s worth noting that water hardness can vary from year to year and even within the same region, so it’s important to regularly check the water quality report provided by your local water supplier to stay informed about the water hardness in your area.

California Water Hardness By City

Los Angeles water hardness

The latest report in 2021 shows that the average Los Angeles water hardness is 112 PPM, and the hardness level is moderately hard.

And here you will find the Los Angeles water hardness statistics since 2004, reported by the Los Angeles Department Of Water and Power.

Year	The Lowest PPM	The Highest PPM	The Average PPM
2021	100	116	112
2020	90	102	95
2019	56	96	78
2018	72	97	88
2017	62	106	84
2016	109	138	126
2015	124	137	133
2014	111	138	119
2013	102	106	105
2012	87	106	102
2011	52	90	76
2010	86	104	93
2009	104	118	110
2008	103	124	113
2007	102	136	118
2006	68	101	88
2005	57	114	96
2004	94	248	134

The water hardness level varies from year to year.

The highest water hardness is 248 PPM which was reported in 2004, since then, the total hardness in the Los Angeles water does not exceed 140 PPM, that’s quite good enough for users.

You can check out all the reports here.

Hard Water In San Diego

In the latest annual Water Quality Reports from the City Of San Diego, the average San Diego water hardness is 245 PPM which is very hard.

Year	The Lowest PPM	The Highest PPM	The Average PPM
2021	224	282	254
2020	127	293	236
2019	135	261	194
2018	133	292	224
2017	138	295	214
2016	245	311	272
2015	251	324	288
2014	171	292	139
2013	136	252	209
2012	116	237	172
2011	144	261	184
2010	199	284	241
2009	299	325	257
2008	209	269	231
2007	194	254	291

Based on the data provided, it appears that the water hardness in San Diego can vary widely from year to year.

The average water hardness in San Diego over the past 15 years ranged from a low of 139 ppm in 2014 to a high of 288 ppm in 2015.

The data also shows that water hardness in San Diego tends to be on the higher end of the scale, with the lowest PPM values ranging from 116 ppm to 299 ppm, and the highest PPM values ranging from 237 ppm to 325 ppm.

These variations in water hardness can have a significant impact on the quality of water for residents and businesses in the area, as well as on plumbing and appliances that come into contact with the water.

You can check out all the San Diego Water reports here.

Hard Water In San Jose

In the water quality report from San Jose Water (SJ Water), the average groundwater San Jose Water Hardness is 361 PPM, and the hardness ranges from 172 to 522 PPM which is extremely hard. With that high of San Jose water hardness, the resident with well water will need to install a water softener system to reduce the hardness minerals that are present in their water.

Year	Lowest	Highest	Average
2016	160	480	310
2017	290	470	330
2018	150	460	310
2019	190	500	320
2020	190	530	350
2021	172	522	361

According to the data provided, the water hardness in San Joe City has been fluctuating in recent years.

The average water hardness in the city ranged from a low of 310 ppm in 2016 and 2018 to a high of 361 ppm in 2021.

The lowest PPM values ranged from 150 ppm to 290 ppm, while the highest PPM values ranged from 460 ppm to 530 ppm.

These variations in water hardness can have an impact on the quality of water for residents and businesses, as well as on plumbing and appliances that come into contact with the water.

California Water Hardness By Zip Code

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