Can All Holiday String Light Sets Be Used Outdoors Safely?

string lights and holiday decorations on house, yard, and trees

Maybe you’re not putting a tree in your living room this year, or maybe you upgraded from incandescent to LED string lights. So maybe those old lights would look good on the tree, bushes, or front of your home.

Can you use any holiday string lights indoors and outdoors?

The short answer to this question is no.

String light sets, whether incandescent strings or LED strings, have Underwriters Laboratory (UL) Listings for either indoor only or indoor/outdoor. The string light boxes (or information shown on the web) should say “Indoor/Outdoor” if the string is UL Listed for both applications.

Sometimes a string that can only be used indoors will not say that on the box, but you should assume, if you don’t see “Indoor/Outdoor”, it means indoor only.

If you are looking for string lights with added durability, choose items that say “Commercial Grade” or Heavy Duty”. These strings are constructed of thicker, heavier material. While they flex as much as most applications require, they are not as flexible or as light weight as standard duty string lights.

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Dave Burtner

Dave has been active in the lighting industry since 1994. Formerly a member of the Illuminating Engineering Society of North America and certified by the National Council On Qualifications for Lighting Professionals, Dave now writes blog posts, lighting tips and provides lighting product assistance for the Topbulb website.