Do Windscreen Sun Shades Work? What They Can and Can't Do
By Laura Pemberton · Updated on 7 October 2026
Short answer: yes, a windscreen sun shade works, within limits. It keeps direct sun off the dashboard, the steering wheel and the front seats, which stay noticeably cooler to the touch and fade less over time. It also reduces the heat building up inside the car on a hot, sunny day. What it can't do is keep a parked car cool: the side and rear windows still let heat in, and the cabin still gets hot. A sun shade is never a reason to leave a child or a pet in a parked car.
How hot does a parked car get?
Hotter than most people expect, even in a British summer. The RSPCA warns that when it is 22°C outside, a car can reach 47°C within an hour. In a US study by Arizona State University and UC San Diego, cars parked in full sun for an hour on days of over 100°F (about 38°C) had dashboards averaging around 69°C and steering wheels around 53°C. Those are Arizona temperatures, but the principle is the same here: the surfaces in direct sun get much hotter than the air.
That is what UK drivers notice. On the PistonHeads forum, one owner wrote: "Drive is south facing and dash (and car) are black so really a sun trap." Another wanted a shade "to stop the leather getting so hot that it dries out and cracks."
What does a windscreen sun shade actually do?
| What it helps with | What it doesn't do |
|---|---|
| Keeps direct sun off the dashboard, steering wheel and front seats | Stop heat coming through the side and rear windows |
| Reduces the heat building up in the cabin on a sunny day | Keep the car cool, or safe, for anyone left inside |
| Protects the dash and leather from long-term sun damage | Replace air conditioning once you are driving |
| Blocks UV through the windscreen | Help much on cloudy days |
The RAC's advice on cooling a car down makes the same point: a windscreen sun shade keeps the sun's rays off the interior, especially the touch points such as the steering wheel. An older study by the Florida Solar Energy Center found that even a basic cardboard shade lowered dashboard temperatures substantially compared with no shade at all.
Which type of sun shade should you choose?
| Type | How it fits | Good for | Watch out for |
|---|---|---|---|
| Umbrella style | Opens like an umbrella and sits against the glass | Quick to put up and take down, stores small | Check it clears your mirror and dashcam |
| Folding concertina | Unfolds across the dash, held by the visors | Cheap, simple | Bulky to store, can sag |
| Roll-up or flat panel with suction cups | Stuck to the glass | Thin, light | Suction cups lose grip and fall off |
| Exterior cover | Over the outside of the windscreen | Also works against frost | Takes longer to fit and to put away |
The most common complaint about cheaper shades is the fit: either gaps around the edges or suction cups that won't stay put. A reviewer of another brand on Amazon UK wrote: "The suction cups ripped out of the material… after the first use!"
How does SunMate™ compare?
Our SunMate™ car sunshade is an umbrella-style shade. It opens like an umbrella, and a reinforced memory frame holds it against the windscreen by natural tension, with no suction cups and no straps. It is one universal size, made to fit the majority of UK cars, from compact cars and saloons to estates and SUVs. Its reflective film is rated UPF50+ and blocks up to 99% of UV rays and heat, and on a hot, sunny day it can keep the car up to 30°C cooler. It folds into its leather-effect case and fits in the glove box.
Its limits are the same as any windscreen shade: it covers the windscreen only, and it will not keep a parked car cool enough to be safe for a child or an animal.
How do you get the most from a windscreen sun shade?
- Park smart first. Shade, or facing away from the sun, beats any accessory.
- Put it up as soon as you park. The heat builds fast in the first hour.
- Push it flat against the glass. Tuck it around the rear-view mirror so there are no gaps at the top.
- Crack the windows slightly if it is safe to do so. It lets some hot air escape.
- Air the car before you set off. Open the doors for a minute, then use the air conditioning.
- Never leave children or pets inside. Not even for a few minutes, sun shade or not.
FAQ
Will a sun shade fit my car?
Most shades come in one or two sizes. SunMate™ is one universal size for the majority of UK vehicles. If you are unsure, check the FAQ on the SunMate™ page or message our UK-based support team.
Does it work with a dashcam or sensors behind the mirror?
SunMate™ sits flat against the glass and tucks around the rear-view mirror. You can reposition it in seconds around a dashcam.
Is a sun shade worth it in the UK?
If your car sits in the sun on a drive or in a car park, yes: the steering wheel and dash are the parts that get hottest, and those are what a windscreen shade protects.
What if it doesn't fit?
You have 90 days to return it, and it is covered by our Lifetime Warranty with free replacement. More summer kit is in our summer essentials.
Sources: RSPCA, "Dogs in hot cars"; Arizona State University, study by Vanos et al. published in Temperature (May 2018); Florida Solar Energy Center, Parker (1990); RAC, "The quickest way to cool your car down" (July 2026).
About the author: Laura Pemberton writes the product copy and blog articles at Vauscher. She also works on product research, helping select the home, garden and DIY products in our range.