When does Cardiff need sun protection?

Whenever the UV index is 3 or above. In Cardiff that is typically from May through September, and any clear spring or fall day UV reaches 3. The UK Health Security Agency and WHO use the same UV Index scale worldwide.

Does Cardiff need sun protection in winter?

Not every day. Midwinter middays in Cardiff often sit below UV 3, but clear late-winter and early-spring days cross the threshold before summer fully arrives. Check the live index.

Does city shade protect you from UV in Cardiff?

Only while you stay in it. Buildings cut some sky, but plazas, crossings and glass bounce UV onto uncovered skin. The live index on this page is the open-sky reading. Treat lunch outside as full-sun time whenever it is 3 or above.

UV index in Cardiff today

Cardiff's bay waterfront and nearby coast reflect extra UV onto uncovered skin. Clear Welsh summer days push the index into the high band even when the breeze feels mild.

Live reading · data by Open-Meteo · reference monitoring by ARPANSA

Today and tomorrow in Cardiff

Peak UV, temperature and conditions for Cardiff. Tomorrow’s peak is the number to plan around if you’re heading out in the middle of the day.

Weather conditions right now

Cloud and rain cut heat more than they cut UV. A partly cloudy day in Cardiff can still sit at protection levels. Why you burn on cloudy days.

When Cardiff needs sun protection

Sun protection is typically needed from April through September in Cardiff, and on any clear day the UV index reaches 3.

The threshold, per SunSmart and ARPANSA: whenever UV reaches 3 or above, Slip on covering clothing, Slop on SPF 50+ sunscreen, Slap on a hat, Seek shade and Slide on sunglasses. Read the full sun safety guide.

Where the UV adds up in Cardiff

Long, happy hours outdoors are where exposure quietly accumulates. Local favourites where the five S’s earn their keep:

Cardiff Bay Barrage walk
Bute Park
Penarth pier and cliffs
Roath Park Lake

The UV scale at a glance

0–2Low
3–5Moderate
6–7High
8–10Very high
11+Extreme

Frequently asked questions

When does Cardiff need sun protection?: Whenever the UV index is 3 or above. In Cardiff that is typically from May through September, and any clear spring or fall day UV reaches 3. The UK Health Security Agency and WHO use the same UV Index scale worldwide.
Does Cardiff need sun protection in winter?: Not every day. Midwinter middays in Cardiff often sit below UV 3, but clear late-winter and early-spring days cross the threshold before summer fully arrives. Check the live index.
Does city shade protect you from UV in Cardiff?: Only while you stay in it. Buildings cut some sky, but plazas, crossings and glass bounce UV onto uncovered skin. The live index on this page is the open-sky reading. Treat lunch outside as full-sun time whenever it is 3 or above.