Why Is My Pool Losing Water in May?
As temperatures begin to rise across the Bay Area, many homeowners start noticing their pool water level dropping faster than usual. If your pool is losing water in May, there’s a good chance it’s completely normal evaporation — especially here in San Jose, CA where warmer weather, wind, and increased pool usage all contribute to water loss.
At PFS Pool Services, one of the most common questions we hear during spring and early summer is:
“Is my pool leaking, or is this just evaporation?”
Here’s how to tell the difference.
What’s Considered Normal Pool Water Loss?
In San Jose and throughout the Bay Area, swimming pools commonly lose water due to evaporation as temperatures increase.
Normal Pool Evaporation Rates:
- About ¼ inch per day → completely normal
- Up to ½ inch per day → still considered normal
- More than ½–1 inch per day → possible pool leak
If your pool water level is dropping beyond these ranges, it may be time to schedule professional pool leak detection.
Why Pools Lose More Water in May
May is typically when Bay Area pools transition back into regular seasonal use. Several factors contribute to increased evaporation during this time of year:
1. Warmer Temperatures
As temperatures rise in San Jose, Santa Clara County, and surrounding Bay Area cities, evaporation naturally increases.
2. Wind Exposure
Wind speeds can dramatically increase water evaporation by constantly moving moisture away from the pool surface.
3. Longer Pool Pump Run Times
Many homeowners increase filtration and circulation hours in spring and summer, which can slightly increase water loss.
4. Increased Pool Activity
More swimming, splashing, and pool use naturally contributes to water displacement and evaporation.
How to Tell if Your Pool Has a Leak
One of the easiest ways to determine if your pool has a leak is by performing a simple Bucket Test.
The Pool Bucket Test
Step-by-Step:
- Fill a bucket with pool water
- Place the bucket on a pool step
- Mark the water level inside the bucket and outside on the pool
- Wait 24 hours without using the pool
Results:
- If both water levels drop equally → normal evaporation
- If the pool water drops more than the bucket → possible leak detected
This simple test can help determine whether you need professional leak detection services.
Signs You May Have a Pool Leak
While evaporation is common, excessive water loss may indicate a hidden leak somewhere in your pool system.
Common Warning Signs:
- Losing more than ½–1 inch of water daily
- Wet spots around your pool equipment or yard
- Pool pump losing prime
- Cracks near skimmers or return lines
- Water level dropping even when the system is turned off
- Air bubbles in return lines
- Constant need to refill the pool
Ignoring small leaks can lead to expensive water bills, structural damage, and equipment issues over time.
Common Pool Leak Locations
At PFS Pool Services, we commonly find leaks in the following areas:
- Pool equipment pads
- Skimmers
- Pool lights
- Return fittings
- Underground plumbing lines
- Valves and fittings
- Main drains
Professional leak detection helps identify the exact source before major repairs are needed.
Professional Pool Leak Detection in San Jose, CA
If you suspect your pool may have a leak, it’s best to address it early before water loss becomes costly. Our experienced team at PFS Pool Services provides professional pool leak detection throughout San Jose and the Bay Area.
We help homeowners determine:
- Normal evaporation vs actual leaks
- Plumbing leak locations
- Equipment-related leaks
- Underground pool plumbing issues
- Pressure testing and repair recommendations
Bottom Line
Most pool water loss in May is completely normal due to evaporation, especially in San Jose’s warmer spring weather. However, if your pool is losing excessive water, dropping when the system is off, or showing signs of leaks, it’s smart to have it inspected early.
PFS Pool Services proudly provides reliable pool maintenance, leak detection, and pool repair services throughout San Jose and the Bay Area.
Contact PFS Pool Services today to schedule professional pool leak detection or weekly pool service.
