Can you tan through a window?

Slightly, over long exposure, UVA stimulates some pigment response. You won't develop a meaningful tan (or burn) through glass in normal timeframes, but the UVA still contributes to ageing and cumulative damage.

Do I need sunscreen while driving?

For a short commute, no. For hours of daytime driving with sun on your side window, broad-spectrum sunscreen or a sleeve on that arm is a sensible habit, Australian drivers' right arms collect a documented excess of sun damage.

Does window tint block UV?

Good automotive films block the large majority of both UVA and UVB, some claim 99%. Factory tint varies. If you drive for a living, UV-rated film on the side windows is one of the cheapest protections available.

Can you get sunburnt through a window or in the car?

Mostly no sunburn, but not no damage. Ordinary glass blocks nearly all UVB, the wavelengths that cause sunburn, which is why you almost never redden behind a closed window. What glass lets through is a large share of UVA: the deeper-penetrating wavelengths behind skin ageing, pigmentation and a meaningful slice of long-term skin-cancer risk.

UVA and UVB behave differently at a window

	UVB (burning)	UVA (ageing, deep damage)
Causes sunburn	Yes, the main driver	Only at extreme doses
Passes through standard glass	Almost none	Up to ~75% through plain glass
Contribution to skin cancer	Major	Significant, especially with chronic exposure
Blocked by 'broad spectrum' sunscreen	Yes	Yes

What about cars specifically?

Windscreens are laminated, two layers of glass bonded with a plastic interlayer, and block most UVA as well as UVB. Side and rear windows are usually tempered, not laminated, and can let through a large fraction of UVA. That asymmetry shows up in dermatology: studies of long-haul drivers repeatedly find more sun damage, actinic keratoses and skin cancers on the driver's-side arm and face, the right side here in Australia.

The practical takeaways: on long drives with the sun on your side, sleeves or broad-spectrum sunscreen on the window arm are worth it; quality window tint or UV film cuts UVA substantially (and is legal within Australian visibility limits); and an open window removes the glass entirely, full UVB, full burn risk, exactly as if you were outside.

Offices, homes and planes

A desk beside a sunny window delivers a small but chronic UVA dose year-round. It won't burn you; over years it contributes to photoaging on the window side.
Double glazing and low-E coatings block more UVA than single-pane glass, but transmission varies, don't assume zero.
Aircraft windows block UVB well, and at cruising altitude UV is far more intense; pilots and frequent window-seat flyers have measurably higher exposure. For a daytime flight over cloud, the window shade is genuine sun protection.

Frequently asked questions

Can you tan through a window?: Slightly, over long exposure, UVA stimulates some pigment response. You won't develop a meaningful tan (or burn) through glass in normal timeframes, but the UVA still contributes to ageing and cumulative damage.
Do I need sunscreen while driving?: For a short commute, no. For hours of daytime driving with sun on your side window, broad-spectrum sunscreen or a sleeve on that arm is a sensible habit, Australian drivers' right arms collect a documented excess of sun damage.
Does window tint block UV?: Good automotive films block the large majority of both UVA and UVB, some claim 99%. Factory tint varies. If you drive for a living, UV-rated film on the side windows is one of the cheapest protections available.

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