Care Guide

What Are The Best Curtains For Blocking The Summer Sun?

What Are The Best Curtains For Blocking The Summer Sun?

Ah, the summer sun! It brings warmth, light, and a cheerful ambience to our homes. But let's face it: sometimes, it brings a little too much of itself, turning our once comfortable living spaces into veritable saunas. That's where sun-blocking curtains come to the rescue! In this comprehensive guide, we'll delve into everything you need to know about choosing the best curtains to keep the summer sun at bay.

What Kind Of Curtains Block Sunlight?

Not all curtains are created equal when it comes to blocking sunlight. The most effective curtains for this purpose are labelled "blackout" or "sun-blocking." These curtains are typically made from thicker, tightly woven fabrics that create a barrier against the sun's rays. Look for multiple-layer curtains or foam backing for maximum light-blocking prowess.

How Do Sun-Blocking Curtains Work?

Sun-blocking curtains, also known as blackout curtains, are designed to block sunlight and provide a cooler and darker environment inside homes. These curtains are crafted from specialised fabrics and employ materials and design features to achieve sun-blocking capabilities. Understanding how they work involves exploring the materials used, the structure of the curtains, and the science behind light and heat blockage.

The fabric is at the core of sun-blocking curtains. The most effective curtains are made from tightly woven fabrics that prevent light from passing through. Common materials include polyester, cotton, and thermal-backed fabrics. These materials are chosen for their density and opacity, crucial for blocking sunlight. Some sun-blocking curtains also incorporate multiple layers of fabric, each serving a specific purpose for light and heat reduction. For instance, the outer layer might be decorative, while the inner layers focus on insulation and light blockage.

One of the key elements of sun-blocking curtains is the backing material. Many of these curtains feature a special coating or lining, often made of foam or rubber, that enhances their light-blocking properties. This backing prevents light from penetrating the fabric and helps insulate the room by reflecting heat away from the interior. This dual function is particularly beneficial during the summer when reducing heat is just as important as blocking light.

The structure and design of sun-blocking curtains also significantly influence their effectiveness. These curtains are typically designed to cover the entire window frame, minimising gaps where light could seep through. Some designs include additional features such as magnetic strips or Velcro along the edges to ensure a tight seal against the window frame. This comprehensive coverage is essential for maximising the curtains' ability to block sunlight and reduce heat gain.

The science behind sun-blocking curtains involves the principles of light absorption and reflection. When sunlight hits a window, it can either pass through, be absorbed, or be reflected. Sun-blocking curtains are engineered to maximise the reflection and absorption of light. The reflective properties of the backing material send sunlight back out of the window, preventing it from entering the room. At the same time, the dense fabric absorbs any light that manages to penetrate, reducing glare and maintaining a darker room environment.

In addition to blocking visible light, sun-blocking curtains help reduce the amount of ultraviolet (UV) and infrared (IR) radiation entering a home. UV radiation can cause furniture, carpets, and artwork to fade, while IR radiation contributes to heat buildup. By blocking these forms of radiation, sun-blocking curtains help protect interior furnishings and lower indoor temperatures.

Beyond their functional benefits, sun-blocking curtains also contribute to energy efficiency. By reducing the heat that enters a home, these curtains lessen the reliance on air conditioning systems, leading to lower energy consumption and cost savings. This makes them an eco-friendly option for homeowners looking to enhance comfort while being mindful of their environmental footprint.

In short, sun-blocking curtains work through dense, tightly woven fabrics, specialised backing materials, and thoughtful design features that ensure comprehensive coverage and maximum light and heat blockage. By reflecting and absorbing sunlight, these curtains create cooler, darker, and more energy-efficient living spaces, making them an invaluable addition to any home during the hot summer months.

Which Curtain Material Is Best For Summer?

Choosing the right curtain material for summer is essential for keeping your home cool and comfortable. Here, we’ll explore various fabric options that are particularly effective during the hot summer months, focusing on their light-blocking capabilities, breathability, and overall suitability for the season.

1.     Polyester

Polyester is popular for summer curtains due to its durability, affordability, and excellent light-blocking properties.

Polyester curtains can withstand the rigours of daily use and frequent exposure to sunlight without losing their shape or colour. Many polyester curtains are specifically designed with a tight weave or additional backing to block out sunlight, keeping rooms darker and cooler effectively. Polyester is easy to clean and wrinkle-resistant, making it a low-maintenance option.

2.     Cotton

Cotton is another fantastic choice for summer curtains. It offers a blend of breathability and functionality. Cotton allows air to circulate, helping to keep rooms cool while still providing adequate sun protection.

Available in a wide range of weaves and thicknesses, cotton curtains can be tailored to meet specific light-blocking needs. Their soft, natural texture adds a touch of comfort and elegance to any room.

3.     Linen

Linen curtains are perfect for summer, combining a light, airy feel with effective sun-blocking properties. Linen is naturally lightweight, making it an excellent option for allowing breezes to pass through while offering sun protection. Its natural, slightly textured appearance adds a casual yet sophisticated touch to home decor. Thanks to its natural insulating properties, linen helps regulate temperature by keeping rooms cool in summer and warm in winter.

4.     Thermal-Backed Fabrics

Thermal-backed fabrics are specifically designed for insulation, making them ideal for summer. They usually have a fabric layer bonded to a thermal or blackout backing. These curtains are excellent at blocking sunlight and preventing heat from entering, thus maintaining a cooler indoor environment.

Thermal-backed curtains can help lower energy costs associated with air conditioning by reducing the amount of heat entering your home. Available in various colours and styles, these curtains can match any decor while providing functional benefits.

5.     Velvet

While velvet might seem like a winter fabric, its dense weave makes it surprisingly effective for summer use; the velvet thickness ensures excellent light-blocking and thermal insulation, keeping rooms cool during the hottest part of the day. Velvet adds a touch of luxury and sophistication to your home, enhancing both aesthetic and functional aspects. Velvet is durable and long-lasting, and it can maintain its appearance and functionality over time.

What To Consider When Shopping For Best Curtains For Summer?

Now that you understand the basics of sun-blocking curtains let's explore some key factors when shopping for the perfect pair to keep your home cool and comfortable all summer.

  1. Light-blocking capability: Look for curtains with a high light-blocking capability, preferably labelled as "blackout" or "sun-blocking." This will ensure maximum protection against the harsh summer sun.
  2. Fabric type: As mentioned earlier, opt for curtains made from heat-resistant fabrics such as polyester, cotton, or linen. These materials not only block sunlight effectively but also help regulate indoor temperature.
  3. Colour and design: While the primary function of sun-blocking curtains is to block sunlight, that doesn't mean they have to be dull! Choose curtains in colours and designs that complement your existing decor while providing adequate sun protection.
  4. Size and fit: Proper sizing is crucial when installing sun-blocking curtains. Measure your windows accurately to ensure a snug fit that minimises gaps where sunlight can sneak through.

How Do I Measure For Sun-Blocking Curtains?

Measuring for sun-blocking curtains is a relatively straightforward process, but it's essential to get it right to ensure optimal light-blocking performance. Here's a step-by-step guide to help you measure your windows like a pro:

  1. Start by measuring the width of your window frame from one side to the other. Add a few inches to each side for maximum light-blocking effectiveness to allow the curtains to overlap the window slightly.
  2. Next, measure the length of your window from the top of the frame to the desired length of the curtains. Remember that sun-blocking curtains are most effective when they extend beyond the window frame and reach the floor.
  3. If you're installing curtains on a sliding glass door or a particularly large window, consider opting for wider curtain panels or multiple panels to ensure adequate coverage.


Choosing the best curtains for blocking the summer sun involves considering factors such as fabric type, light-blocking capability, colour, design, and proper sizing. Selecting curtains made from heat-resistant materials and ensuring a snug fit can keep your home cool and comfortable even on the hottest summer days. So bid farewell to sweltering heat and hello to a shady oasis with the perfect sun-blocking curtains for your space!


What curtains are best to block out heat?

Curtains labelled "blackout" or "sun-blocking" are the best options for blocking heat, specifically designed to deflect and absorb sunlight.

Are there any health benefits to using sun-blocking curtains?

Yes, sun-blocking curtains can offer several health benefits, including protection against harmful UV rays, reduced glare, and improved sleep quality by creating a darker sleeping environment.

Can sun-blocking curtains help reduce energy costs?

Yes, sun-blocking curtains can help reduce energy costs by minimising the heat entering your home, thus reducing the need for air conditioning and cooling appliances.

Do sun-blocking curtains fade over time?

While sun-blocking curtains are designed to withstand prolonged exposure to sunlight, some fading may occur over time, particularly with curtains made from lighter-coloured fabrics. However, choosing curtains with fade-resistant properties can help prolong their lifespan and maintain their aesthetic appeal.

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