Change your preferences here.
Summons sunlight for 5 turns. If the user is holding the item Heat Rock, it lasts for 8 turns instead. While in effect, it increases the damage of Fire-type moves by 50%, and causes Water-type moves to do half damage. Thunder is 50% accurate. SolarBeam has no charge turn. Moonlight, Morning Sun, and Synthesis heal 2/3 of the user's maximum HP. No Pokémon can be Frozen while the sunlight is active. Pokémon with the Chlorophyll ability have double Speed. Pokémon with the Forecast ability become Fire-type. Pokémon with the Leaf Guard ability are unaffected by status inducing moves. Pokémon with the Flower Gift ability and its partner in 2v2 have an increase in stats. At the end of each turn, Pokémon with the Dry Skin or Solar Power abilities lose 1/8 of their total HP. The latter also gets a one stage Special Attack boost.
Smogon has an article on this topic.
Hail is an Ice-type equivalent.
Rain Dance is a Water-type equivalent.
Sandstorm is a Rock-type equivalent.