iPhone screen dims in sunlight

Hey, I think I fixed this finally. It’s been frustrating me for years. I do a lot of outdoor work and I live in Orlando, FL. Yes. The Sunshine State. ☀️ 🤦🏻‍♂️

Turn True Tone off.

Settings > Display & Brightness.

Hey Apple. This shouldn’t behave like this. Looks like you have a bug to fix. The color spectrum of daylight, 6500 K, may be off the end of the scale of where the iPhone is reading the ambient lighting, then causing it to default to the factory default, perhaps? This may be more prevalent in southern or high altitude areas, or especially bright days.

I am literally on Daytona Beach. Been here a hundred times. I can actually read my screen without straining.

Here’s what’s happening specially:

Auto Brightness Off

Brightness at 100%

True Tone On

In bright daylight, the screen dims. If anything, we should get the opposite. A little boost, like 120%.

Turn True Tone Off: The screen stays bright.

Hit me up if I can help more.

I think I figured this out.

I had the screen dim a couple of months ago while I was watching something on Apple+ in my home. The phone has a case on it and felt warm. I took the case off and the phone itself was hot. about 5 - 10 minutes later, the phone felt cooler and the screen brightened back up.

I've been watching for the screen dimming on its own and the phone was fairly hot each time.

The phone's heat dissipation properties are probably not engineered to consider the various types of plastic or silicone cases we're using. They are essentially insulation that impairs the phone's ability to stay cool.

The solution here may very well be to remove the case when you need brightness all the way up and the screen has dimmed on its own for no apparent reason.

Hey Apple! Maybe you could let us know if this is the case and, if so, make this feature more public. Like: "The phone screen will dim if the phone overheats. Phone cases can impede the phones ability to stay cool".

Love to know what everyone else has discovered. When this happens, take it out of the case. Is the case hot? Does the screen brighten back up after the phone cools off?

Found it:

Settings > accessibility > display and text size > scroll down > reduce white point (off)

Was having this issue for ages. Tried everything from factory reset, to turning off auto brightness and resetting phone, to taking to the Apple “Geniuses.”

This just started happening to me this week after I plugged my 13 pro into my new MacBook Air and some update was required. I had Auto-Brightness and True Tone off in the Display & Brightness section. But as srbwanderer

mentioned there are 2 places to turn it off.

1) Go to Settings > Displays & Brightness > Appearance. Turn Automatic off.

2) Go to Settings > Accessibility > Display & Text Size. Turn Auto-Brightness off.

What did it for me is under #2, there is another option to "REDUCE WHITEPOINT" which seems to be a new feature and automatically switched on. I turned it off and its back to normal finally.

After trying every step mentioned in this discussion thread, I continued to have the same issue. On a whim, I turned off the Zoom feature <Settings>, <Accessibility>, <Zoom>, <Off>. The screen immediately flashed and went to full brightness. Apple - what does Zoom have to do with screen brightness? Sounds like Apple has a software glitch! Hope this simple setting change works for some of you out there experiencing the same frustration.

The screen dimming OP is referring to on some iPhones isn’t a bug—it’s by design to prevent the device from overheating, especially during intensive tasks, when in the sun or above average temperatures or if a cover on the phone doesn’t allow the back of the phone to ventilate (most covers).

While there are settings to adjust or disable some dimming behaviours (like auto-brightness), no setting allows users to override the dimming triggered by thermal management.

If anything, this could be considered a design limitation. Apple prioritizes sleek aesthetics in its devices, often at the expense of practicality, which is why overheating can occur in the first place. However, this safety feature ensures the device remains functional and doesn’t sustain damage due to excess heat.

Hi relsson,

To clarify, does this only happen after your device has been in the sun? If so, this could be normal behavior as a result of temperature as outlined below: If your iPhone or iPad gets too hot or too cold - Apple Support

"Avoid these conditions and activities because they might change the performance of your device:

• Leaving your device in a car on a hot day.
• Leaving your device in direct sunlight for an extended period of time.
• Using certain features in hot conditions or direct sunlight for an extended period of time, such as GPS tracking or navigation in a car, playing a graphics-intensive game, or using augmented-reality apps.

If the interior temperature of your device exceeds the normal operating range, you might notice these changes:

• Charging, including wireless charging, slows or stops.
• The display dims or goes black.
• Cellular radios enter a low-power state. The signal might weaken during this time.
• The camera flash is temporarily disabled.
• Performance slows with graphics-intensive or augmented-reality apps or features."

This could account for what you're seeing. If you need further assistance, use this link to contact us directly: Get Support

Take care.

I still think its a heat issue. Bright screens put off a lot of heat and you may not realize, but it might be too much for the internals of the phone or it may just be trying to prevent too much heat from occurring in the first place. I deal with this issue all the time.

Ill be sitting outside, and suddenly my screen is almost too dark to see. And if I try to turn it up, it does nothing. Sometimes I can slide the brightness bar from 50% to 100% and back and forth with 0 difference in brightness. So yes, I think its a heat thing given the iPhone does not have an active cooling device inside of it. Would you rather the phone dim the screen a little bit or would you rather it come up and say, "iPhone needs to cool down before you can use it."

Annoying? Yes. Necessary? Also yes.

A new development.

Today I went out biking with my iPhone, and saw that it turned nearly black in the sun. I moved to a shaded area (a gazebo with trees by one side) to try to change a Music playlist, still unreadable.

Then by chance I turned it to landscape orientation and suddenly I could see it better. My polarizing clip-on sunglasses made it dark in portrait orientation. I took them off and it got even better.

My old Motorola Android phone was polarized the opposite way. I could see it in portrait mode with my sunglasses well enough to use a speedometer and geo-tracking app while it was mounted on the handlebars, but not in landscape orientation.

That choice of polarization on the iPhone screen seems like a design flaw to me.

My old iPod touch has the same polarization as the iPhone, but it's not so dramatically dark. It just turns purple.

Many replies with people talking about different settings to change it’s all bull and waste of time unless you are really a level 1 user.

For the rest of us, it’s as I said before “by design”, if phone gets warmer and warmer (cpu usage, external temp, phone cover, etc) screen will dim to manage the temp. It’s the tax we pay for having slick design passive ventilation - the end.

Try turning off True Tone. That seemed to work for me.

I am getting the screen dimming at random times now while indoors, even with auto dim and true tone off. There's definitely a bug in the software.

Has anyone tried taping over the ambient light sensor to prevent this? It must be using some brightness input to adjust the screen brightness. Why not blind the sensor if we're already disabling true tone and auto brightness?

Yes, have the same issue and this is always related to the iPhone getting hot. There are some 3d printed solutions to make screens fore visible under strong sunlight, like special visors/cased. Some of them here:

https://makerworld.com/en/models/498227#profileId-412777

https://makerworld.com/en/models/487189#profileId-399997

I just tried something!: go to Settings: Display and Text size: then reduce White Point to 0%.

it worked! Try it out!

Hello relsson,

There are actually two different places to adjust automatic brightness. You can see the steps to turn both of them off below:

1. Go to Settings > Displays & Brightness > Appearance. Turn Automatic off.
2. Go to Settings > Accessibility > Display & Text Size. Turn Auto-Brightness off.

If you think the screen is still changing with these set to off, tap on Settings > Displays & Brightness. Note where the Brightness slider is set. When you think the brightness has changed, come back to the slider and see if it is where it was left.

If it has moved, we would suggest reaching out to Apple Support here: Get Support  

They will be in the best position to assist further.

Cheers.