The Solstice Event coming to Pokémon GO is the a new take on a Pokémon GO event celebrating the summer season with a precedent set in 2017. Although there's not much known officially about the event at this point, Niantic has released timing for the event. Combining that with knowledge of past iterations can give fans a sense of how this year's version will look.
Solstice Event Pokémon GO: What You Need to Know
Pokémon GO developer Niantic announced the 2020 solstice-themed event Friday as one of two events set for this summer. It is scheduled to run Friday, June 19 at 8 a.m. local time to Wednesday, June 24 at 10 p.m. local time. Niantic plans to share more information about the event as it nears.
In the 2017 Solstice Week event, Fire- and Ice-Type Pokémon had increased spawns. Pokémon like Charmander, Cyndaquil, Growlithe, Houndur, Ponyta, Swinub, Vulpix and their evolutions appeared more frequently. Sneasel, Magmar, and Cloyster also appeared.
Trainers received bonus XP for catching Pokémon with Nice, Great and Excellent Throws, and for Curveballs and First Throws. Hatching Eggs earned trainers triple XP.