You can expect a typical backyard pool to lose roughly 0.25–0.5 inches of water per day to evaporation in warm weather, though the exact amount depends heavily on climate, wind, humidity, temperature, and whether you use a cover.

Quick Scoop

  • Most residential pools lose about 0.25 inch of water per day under normal conditions.
  • In hot, dry, windy areas, that can climb to 0.5 inch or even close to 1 inch per day for uncovered, heated pools.
  • In cooler or more humid climates, loss is often closer to 0.125–0.25 inch per day.
  • A medium‑size pool (around 400 sq ft of surface area) can lose roughly 60–120 gallons per day at 0.25–0.5 inch of evaporation.
  • Using a pool cover can cut evaporation by about 70–95%, which also saves heat in heated pools.

How that looks in real life

Imagine a standard in‑ground pool about 16 ft × 32 ft (just over 500 sq ft of surface area):

  • At around 0.25 inch per day, you might lose roughly 75–100 gallons daily.
  • Over a week, that’s roughly 2–3 inches of water loss, which many pool owners notice as a visible drop in the waterline.
  • Over a season in a hot, dry climate, total evaporation can add up to 10,000–25,000 gallons for an uncovered pool.

Because so many people post online worrying they “must have a leak,” a recurring theme in forum discussions is that this kind of steady 0.25–0.5 inch per day drop is usually just normal evaporation, not a hidden crack or broken pipe. Many pool owners use simple “bucket tests” to compare how much water a bucket loses versus the pool over 24 hours to confirm whether it’s evaporation or a leak.

What makes a pool evaporate faster?

Key drivers that speed up evaporation include:

  1. Wind
    • Even moderate wind (5–15 mph) carries away moist air above the pool and can significantly increase evaporation.
 * Exposed, hilltop, or coastal pools tend to lose more water.
  1. Low humidity
    • Dry air can absorb more water, so desert or semi‑arid climates often see 0.375–0.5 inch (or more) evaporation per day in warm months.
  1. High temperature and sun
    • Strong sun and higher air temperatures heat the water surface, giving water molecules more energy to escape.
 * Heated pools may evaporate 2–4 times faster than unheated pools in the same conditions.
  1. Water features and activity
    • Fountains, waterfalls, bubblers, and lots of splashing/rough play increase surface area and mixing, which boosts evaporation.

Normal evaporation vs. possible leak

Many city water boards, pool pros, and leak‑detection companies share similar rules of thumb:

  • Typical daily loss:
    • Around 0.25 inch per day is common and usually considered normal.
* 3–7 mm per day (roughly 0.12–0.28 inch) is often cited as a normal range depending on local climate.
  • Warning signs of a leak:
    • Loss consistently greater than about 0.5–1 inch per day in mild conditions.
    • Water loss that speeds up dramatically on calm, cool days.
    • Wet spots around the pool, shifting deck, or air in the pump system.

Forum conversations often revolve around people seeing 1–2 inches gone over several days in hot weather and wondering if they have a leak; many replies point out that in mid‑summer, with strong sun and wind, that rate may still be within normal evaporation, especially without a cover.

Simple way to estimate your own evaporation

A quick “bucket test” is often recommended:

  1. Fill a bucket with pool water and place it on a step so the water level inside matches the pool level.
  2. Mark the water level inside the bucket and on the pool wall.
  3. Wait 24 hours with the pump running normally and no major splashing.
  4. Measure both drops:
    • If the pool and bucket dropped about the same amount, it’s likely normal evaporation.
    • If the pool dropped significantly more than the bucket, you may have a leak.

Some municipalities and pool services also suggest using a simple formula: multiply pool length × width × water loss in feet × 7.48 (gallons per cubic foot) to estimate total gallons lost to evaporation.

SEO bits (for your post)

  • Focus keyword how much water evaporates from a pool fits naturally into headings like:
    • “How Much Water Evaporates From a Pool Each Day?”
    • “Pool Evaporation: What’s Normal and What Isn’t?”
  • You can safely say something like:

Most pools lose about a quarter inch of water per day to evaporation, and in hot, dry, windy climates this can climb to half an inch or more, especially without a cover.

A short meta description could be:
“Learn how much water evaporates from a pool each day, what counts as normal loss, and when to suspect a leak, plus simple tests and tips to cut evaporation.”

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.