The best lighting for cold and unheated spaces

Everything LEDs replaced behaved badly in the cold. Fluorescent tubes depend on mercury vapor pressure, which falls with temperature: below about 50F they start dim and take minutes to come up, and colder than that they may not strike at all. Metal halide needs a warm-up in any weather and does not enjoy sudden temperature swings.

LEDs have the opposite problem, which is to say they do not have it. Access Fixtures gives typical LED operating ranges as -40F to 185F, and notes that the hot end is the hard end - heat is what shortens an LED's life, and a cold garage is a comfortable place for one to work. They come on instantly at full output.

So the honest headline for this page is short: if a cold garage or shed still has fluorescent tubes, changing them to LED is the single biggest improvement available, and it is not close. The rest of the page is about the small print.

1. A published operating temperature range. This is the specification that answers the question directly, and most makers simply do not print it. Where one does, it is worth preferring that product for an unheated space.
2. Damp or wet rating. Unheated buildings swing between cold and warm air, and condensation is the result. A damp rating is the minimum for a garage; an exposed fitting that can take rain needs wet - wet vs damp rated has the distinction.
3. The fixture rating, not just the bulb. A cold-tolerant bulb in a fitting that is not rated for the location is still the wrong install.
4. Sensors, if any. Motion and photocell products add components with their own limits. If the space regularly goes below freezing, a plain fixture on a switch is the more reliable choice.
5. Linkability and mounting. Cold spaces are usually big spaces. Fixtures that chain together from one outlet save an extension cord per bay.

Sunco 4 ft LED shop light, 4,500 lm - the pick, because it publishes the number. 4,500 lumens from 40 watts at 5000K, damp rated, linkable up to four fixtures from one plug, 50,000 hours and a 7-year warranty - and Sunco publishes an operating range of 4F to 113F, which almost nothing else in this category does.
Cons: not dimmable; no CRI published; 5000K only, which is right for a workshop and wrong if the garage doubles as a room; and 4F is a published floor, not a promise about a Minnesota January.

Hykolity 4 ft shop light - more light per fixture. 6,500 lumens at 5000K for 60 watts, with cords, chain and mounting hardware in the box. If the priority is covering a bay in one hang, this is the brighter fixture.
Cons: no operating temperature range published, which on this page is the thing we are judging; no CRI; not dimmable.

Genie GLEDB2 opener bulb - for the one socket in a cold garage that gets abused. 800 lumens at 4000K, damp rated, vibration and shatter resistant to 5Gs, and made by an opener manufacturer to limit radio interference with the remote.
Cons: no operating range published; 800 lm is modest; not dimmable. The wider problem is in garage door opener bulbs.

Feit PAR38 dusk to dawn - for the outside of the building. 1,050 lumens with CRI 90 and selectable 2700K to 5000K, switching itself on at dark - which is what you want at a shed or a detached garage you walk to in the dark.
Cons: the photocell is the component with the least published cold data of anything here; not dimmable; and it needs a fitting rated for its exposure.

Expect condensation, not just cold. The damp rating matters more in a garage than the temperature rating, because the air in an unheated building carries moisture onto cold surfaces every time the weather turns.

Keep sensors indoors where you can. If the space needs motion control, a switch-side control in a heated part of the building is more reliable than a sensor sitting in the cold.

Do not put a cold garage on a dimmer. Most shop fixtures are not dimmable, including both here, and a dimmer on a non-dimmable load is a fault waiting to happen.

Mind the opener. Some LED bulbs interfere with garage door remotes, which is a separate problem from the cold and a more common one - garage door opener bulbs covers what the opener makers publish about it.