Arches National Park is at its best during spring and fall, but it can be surprisingly pleasant during the winter season. The park is very beautiful during the winter, particularly when it has a dusting of soft snow.
Many people also camp in the park during the winter and that can be enjoyable if you have appropriate gear. If cold-weather camping is not your thing, great lodging options are available nearby in Moab. Some excellent properties offer off-season discounts.
The park's scenery changes very little from season to season. Juniper trees are common in the park and they stay green year-round. Cottonwood trees grow in the bottom of washes and they lose their leaves. The main attractions - the red sandstone formations - take on a richer hue during moist weather and look incredibly beautiful when flocked with snow.[source]