San Diego, CA water hardness

San Diego's tap water measures 276 ppm, which is very hard. The number comes from City of San Diego Public Utilities's 2025 published data, measured at the tap.

Score

276 ppm

Very hard

San Diego shower water

Hardness bands per the U.S. Geological Survey. Range: 276 to 308 ppm across service areas.

276

Soft
0–60

Moderately hard
61–120

Hard
121–180

Very hard
181+

Source: City of San Diego Public Utilities, 2025.

Verified August 2026 against the utility's published figures.

Elsewhere in California, San Jose tests at 155 to 545 ppm and Fresno at 129 ppm.

What this means

What San Diego Water Means for Hair and Skin

Above 180 ppm, minerals leave visible scale on fixtures, soap struggles to lather, and hair and skin carry a film that rinsing doesn't remove. This is the range where people notice hard water without being told.

What removes it

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Water tests soft on a standard hardness strip

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Check your zip

Check Your Own Zip Code

Check the number for your exact address with the free zip lookup, or read the utility's own report linked above.

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