When summer is at its hottest, your backyard swimming pool should be a place to cool off—not feel like a giant bathtub. But during peak heat waves, direct sun and high air temperatures can cause your pool water to heat up fast, making swimming uncomfortable and even unsafe due to bacterial growth.

Fortunately, there are effective ways to prevent your pool water from getting too hot and keep it at a refreshing temperature all season long.

☀️ Why Pool Water Overheats

Understanding the causes of rising water temperatures helps you manage them better:

• Prolonged direct sunlight

• Ambient air temperatures above 90°F (32°C)

• Lack of shade or landscaping around the pool

• Heat-retaining pool covers left on during the day

• Inefficient water circulation or stagnant water

✅ Practical Ways to Keep Your Pool Cool

Here are some easy, proven strategies:

1. Use a Pool Fountain or Waterfall

Moving water cools faster than still water. Installing a fountain, waterfall, or aerator helps:

• Increases water circulation

• Enhances evaporation (natural cooling)

• Adds a refreshing visual and sound element

Tip: Run the fountain overnight when temperatures drop for the best effect.

2. Install a Pool Chiller or Heat Pump with Cooling Option

For areas with consistently high temps, mechanical cooling is very effective.

• Pool chillers: Specifically designed to lower water temperature

• Heat pumps with reverse cycle: Can cool and heat, depending on settings

While more expensive, they provide consistent, reliable cooling in extreme conditions.

3. Add Shade Structures Around the Pool

Blocking direct sunlight helps reduce heat absorption.

• Install umbrellas, pergolas, or retractable awnings

• Plant trees or tall shrubs (just ensure leaves don’t clog filters)

• Use shade sails strategically over shallow ends

Bonus: Shade also helps protect swimmers from sunburn.

4. Remove Your Pool Cover During the Day

Solar covers are great for retaining heat—but terrible for cooling.

• Do not leave thermal covers on during peak sun hours

• Instead, use a mesh cover if you need protection from debris

• Remove any covering early in the morning to let water breathe

5. Run Your Pool Pump and Filter at Night

Nighttime temperatures are naturally cooler. Running your system after sundown helps circulate and cool the water more efficiently.

• Set a timer to run between 9 p.m. and 6 a.m.

• Combine with water features (like fountains) for better cooling

6. Add Ice in Small Pools (Temporary Fix)

For above-ground or small inground pools, adding large bags of ice can quickly bring down the water temperature.

• Temporary fix for pool parties or events

• Not practical for large pools but helpful in a pinch

7. Drain and Refill a Portion of Water

If your pool water is consistently too warm:

• Drain 6–12 inches and refill with cooler hose water

• Do this in the early morning to minimize heat gain

• Be sure to rebalance water chemistry after refilling

8. Use Light-Colored Pool Finishes

If you’re building or resurfacing, choose materials that reflect heat rather than absorb it.

• Light blue, white, or sand-colored tiles or plaster stay cooler

• Dark colors may look dramatic but retain more heat

Jordan Hidalgo’s Tip:

"Pool design plays a long-term role in temperature control—plan smart from the start."

🔁 Maintenance Matters Too

Poor water circulation and dirty filters can cause stagnant water, which heats faster. Make sure to:

• Clean filters regularly

• Keep skimmer and pump baskets clear

• Maintain proper water levels and chemical balance

🌡️ Ideal Pool Temperatures

• Recreational Swimming: 78–82°F (25–28°C)

• Lap Swimming/Exercise: 80–84°F (26–29°C)

• Too Hot: Anything above 88°F (31°C) feels uncomfortable and risks faster algae growth

Final Thoughts

Overheated pool water can take the fun out of summer swimming. But with a few thoughtful upgrades and simple maintenance habits, you can enjoy crisp, cool, and refreshing water even during the hottest weeks of the year.