Instead of meringue (and a bake-free option) top with whipped cream instead once the lemon filling has cooled.
For canning (Mason) jars, because they are not made of tempered glass and can shatter with sudden temperature changes, you must set them in a hot water bath when used in the oven: Place Mason jars in a tall-sided roasting pan or baking dish and fill with hot water until the water level comes half way up the jars. Once the meringue is lightly golden, remove and let cool on a wire rack in a draft free spot.