Outdoor LED lighting
Ratings, sensors, solar and 12 V landscape systems, and light that stays out of the sky
A wet-rated light, marked "Suitable for Wet Locations", is built and tested for direct exposure to rain, snow and sprinklers; a damp-rated light only for moisture under cover, such as a roofed porch. Outside North America the same protection is stated as an IP code, such as IP44 or IP65.
Outdoor lights have to survive weather, switch themselves on and off, and light the ground rather than the sky. LEDs suit the job: they start instantly in the cold, last for years in fixtures that are hard to reach, and run happily on 12 V and on batteries. This guide covers ratings, what to use where, controls, solar, low voltage and dark-sky lighting, and four detailed guides go deeper.
Wet, damp and IP ratings outdoors
Any light exposed to rain, snow or sprinklers must be rated for wet locations; under a roofed porch, damp-rated is enough. These are UL and CSA listings in North America, and UL's wet rating assumes mounting at least 4 feet up. Elsewhere, IP codes do the job: IP44 resists splashing, IP65 water jets, IP67 temporary immersion.
The US National Electrical Code defines a damp location as one protected from weather but subject to moderate moisture, such as a canopy or a roofed open porch, and a wet location as one exposed to weather, or underground and in masonry in contact with earth. The rating belongs to the fixture: a wet-rated lantern protects the lamp inside it, which then only has to suit an enclosed fixture, while a bare PAR38 floodlight lamp must itself be rated for wet locations. Lights mounted lower than 4 feet, such as bollards, need UL's extra marking "Suitable for Mounting Within 4 Feet of Ground". Near pools, ponds and fountains separate rules apply, and many low-voltage transformers must sit at least 10 feet from the water unless listed for that use. The IP ratings table explains every code.
Cold is not a problem for LEDs. Their efficiency rises as the temperature falls, and in one U.S. Department of Energy test an LED fixture gave about 5% more lumens per watt at −5 °C than at 25 °C, while some compact fluorescent lamps give only half their light at freezing. The catches are that an LED makes too little heat to melt snow off its lens, and that the batteries in solar lights charge poorly below 0 °C.
Choosing lights for each part of the yard
Match the light to the job. Entrances need a shielded wall light on a dusk sensor; paths need low lights that shine down; driveways and side yards suit motion-switched floodlights; and gardens suit low-voltage path and spot lights. Whatever the job, choose warm white, shield the source from view, and light only what needs to be seen.
| Where | Typical light | Rating | Control |
|---|---|---|---|
| Entrance, porch | Shielded wall or ceiling light | Damp under a roof, wet if exposed | Photocell or astronomical timer |
| Paths, steps | Low path, step or bollard lights | Wet, rated for mounting near the ground | Timer or photocell on the transformer |
| Driveway, side yard | Floodlight or wall pack aimed down | Wet | Motion sensor with a built-in light sensor |
| Garden, trees, walls | 12 V spot and wash lights | Wet, landscape-listed | Timer or photocell on the transformer |
| Pool, pond, fountain | Underwater or in-ground lights | Listed for the use, IP68 | Timer |
| No wiring nearby | Solar stake, string and wall lights | Wet or IP44–IP65 | Built-in dark sensor |
Color matters outdoors too. Most homes look best at 2700–3000 K, which also causes less glare and skyglow and attracts fewer insects than cool white (see color temperature). Floodlights are the usual source of complaints from neighbors: a floodlight aimed down at the driveway lights the driveway, while one aimed outward lights the street and the house opposite.
Photocells, timers and motion sensors
Three controls switch outdoor lights automatically. A photocell turns them on at dusk, at about 1.5 footcandles (16 lux) for a standard streetlight control, and off at dawn. An astronomical timer calculates sunset from the date and location. A motion sensor turns a light on only when a warm body moves through its view.
They are often combined: most motion sensors include a light sensor, so they stay off in daylight, and a photocell can feed a timer that switches the lights off at midnight. LED loads are light in watts but hard on switches, because an LED driver draws a brief inrush current many times its running current when it switches on. Choose controls rated for LED or electronic loads. The detailed guides cover dusk-to-dawn photocells, including which way to face them, and motion-sensor lights, including why LEDs glow on two-wire sensors.
When solar lights work, and when they don't
A solar light can only spend what its panel collected that day. In June that is plenty almost everywhere, but a London garden gets about one-seventeenth as much sunlight per hour of darkness in December as in June, Seattle about one-thirteenth and Phoenix about a quarter. Solar suits marker and accent lights; wired lights suit security and steps.
That one ratio explains why the same light shines all night in summer and for an hour or two in winter. The rest is placement and chemistry: the panel needs direct sun and a clean surface, the battery is a small nickel-metal hydride (NiMH) cell that must never be replaced with an alkaline one, and the panel itself is the dark sensor, so a nearby porch light can keep a solar light switched off. The solar garden lights guide has the circuit, the sunlight data for seven cities, a worked example and the fixes that help.
12 V low-voltage landscape lighting
Low-voltage landscape lighting runs path and spot lights at about 12 V from a transformer plugged into an outdoor outlet. In the US, UL 1838 limits these systems to 15 V and 25 A per circuit, so cable can be buried just 6 inches deep. Size the transformer by volt-amperes and the cable by load and length.
Each fixture lists its load in volt-amperes (VA), which is what the transformer must supply: a small LED path light may need only 2–5 VA where a halogen one used 10–20 W. Load the transformer to no more than 80% of its rating. Long 12 V runs lose voltage, which LEDs tolerate far better than halogen lamps; most LED landscape fixtures accept roughly 9 or 10 V up to 15 V. Mount the transformer at least 12 inches above the ground and plug it into a GFCI-protected outlet. The transformer sizing guide works through the arithmetic, with voltage-drop tables.
Dark-sky friendly outdoor lighting
DarkSky International and the Illuminating Engineering Society set five principles: light should be useful, targeted, no brighter than needed, controlled by timers or sensors, and warm in color. In practice that means fully shielded fixtures that send no light above the horizontal, 3000 K or warmer, and lights that switch off or dim when not needed.
Unshielded and fully shielded fixtures
DarkSky Approved fixtures must be 3000 K or warmer and offer dimming, and the American Medical Association has recommended 3000 K or lower for community lighting since 2016 (see streetlights). Shielding usually saves energy as well as the view: light that goes up or sideways is light that is not on the path. Near sea-turtle beaches and other sensitive habitats, amber LEDs are the standard choice.
Frequently asked questions
Can I use an indoor LED bulb outdoors?
Inside a fixture that protects it, usually yes: a covered porch light only needs a lamp that suits the fixture, including an enclosed-fixture rating if the globe is sealed. A lamp exposed to rain, such as a floodlight in a bare socket, must be rated for wet locations.
Do LED lights work in cold weather?
Yes, better than in heat: LED efficiency rises as the temperature falls, and they start instantly in the cold. Two catches: an LED gives off too little heat to melt snow on its lens, and the batteries in solar lights accept less charge below freezing.
What color temperature is best for outdoor lights?
2700–3000 K for homes. Warm light causes less glare and skyglow and attracts fewer insects, and dark-sky guidance and the American Medical Association recommend 3000 K or lower. Amber is best near wildlife habitats such as turtle nesting beaches.
Why does my outdoor LED glow or flicker when it is off?
Usually a two-wire motion sensor, lighted switch or photocell passes a small current that the LED driver stores and releases. A sensor with a neutral wire, an LED-rated control or a load capacitor fixes it; see motion-sensor lights.
Do I need an electrician for low-voltage landscape lighting?
Plug-in transformers made for homeowners connect to an outdoor GFCI-protected receptacle with a weatherproof in-use cover, and the 12 V cable is buried shallowly. Adding a new 120 V outlet or hardwiring a transformer usually needs a permit and an electrician; check local code.
Sources and further reading
- NFPA 70, National Electrical Code (2023): Article 100 (damp and wet locations), 410.10(A), Article 411 (low-voltage lighting) and Table 300.5 (cover depths).
- UL 1598, Luminaires (wet-location and within-4-feet markings, as summarized in "Lamps in the Damp", Electrical Contractor); UL 1838, Low Voltage Landscape Lighting Systems.
- IEC 60529, Degrees of protection provided by enclosures (IP Code).
- ANSI C136.10, locking-type photocontrols; TE Connectivity LUMAWISE ALR 8000 and Acuity Brands DTL photocontrol specifications (1.5 fc turn-on).
- European Commission Joint Research Centre, PVGIS 5.3: monthly horizontal irradiation, 2005–2023.
- Association of Outdoor Lighting Professionals (AOLP), Landscape Lighting Guidelines (2021).
- U.S. Department of Energy, "Using LEDs to Their Best Advantage" and solid-state lighting niche-applications reports (cold-temperature performance).
- DarkSky International and Illuminating Engineering Society, Five Principles for Responsible Outdoor Lighting (2020); DarkSky Approved luminaire program requirements.
- American Medical Association, CSAPH Report 2-A-16, Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting (2016).
Image credits
- Entrance at dusk: AI-generated illustration for LEDlights.org.
- Shielding diagram: LEDlights.org.