Does cold weather affect Level 2 EV charger speed at home?

No, not within the range these units are built for. Three Level 2 home chargers checked directly against their own manufacturer documentation -- the ChargePoint Home Flex, the Grizzl-E Smart, and the Emporia Classic -- each publish an ambient operating-temperature range of -22°F to 122°F (-30°C to 50°C), and each is listed to UL 2594, the safety standard covering electric vehicle supply equipment. A charger that is inside that range delivers its rated amperage the same way in January as it does in July.

The three products are made by different companies on different hardware, and all three land on the identical floor. That is a real, checked convergence across the units this article looked at -- it is not a claim that every UL 2594-listed charger on the market shares it, and a reader with a different make should confirm against that unit's own documentation before assuming it matches.

The vehicle's battery, not the charger, is almost always the reason. A lithium-ion EV battery has to sit in a working temperature window to accept charge efficiently, and below roughly freezing the car's own battery-management system throttles the current it will accept, independent of what the Level 2 charger on the wall is capable of delivering. Cabin preconditioning draws from the same plugged-in session when the car is warming its battery or interior before a drive, which can make a cold-weather session look even slower.

A 120V Level 1 cordset shows the sharpest version of this effect, already covered elsewhere on this site: it returns 3 to 5 miles of range per hour in mild weather and can drop close to nothing on a deeply cold night, because a 120V circuit has almost no headroom left once the battery-conditioning draw is subtracted. A Level 2 circuit has more headroom, so the same effect shows up as a slower session rather than a stalled one.

Check the nameplate or spec sheet for two things: an ambient operating-temperature range that covers your coldest night, and an enclosure rating -- Type 3R or similar -- that covers outdoor exposure to rain and snow, not just cold air. All three chargers checked for this page carry both: a -22°F to 122°F operating range and a NEMA 3R (ChargePoint) or NEMA 4 (Grizzl-E, Emporia) enclosure rating for indoor or outdoor mounting.

Plug in earlier and leave the car connected, since a battery that preconditions while still plugged in draws that energy from the wall instead of from the pack. Parking in a garage, even an unheated one, keeps the battery several degrees warmer than an exposed driveway and shortens how long the car spends throttled. Neither of these changes what the charger itself can deliver -- they reduce how long the vehicle's own battery-management system holds the rate down.