Hosmer Lake is good in the upper lake and channel on callibaetis in all stages and most days offer a fair to good hatch. Don’t pass up chironomids, damsels, scuds, leeches and traveling sedge and black caddis and keep an eye out for alderflies too. When it warms up again if you are on the water at dusk or dawn add some trico patterns. The hatch is a caenis mayfly but the pattern that matches it is a trico. Usually spinners or a comparadun are your best bets. 
Troy likes to fish a Chubby with a balanced damsel, I like the Blue Chubby with an adult damsel or Cope’s damsel as a dropper. 
Ants along the reeds are a solid choice and another option is a platinum soccer mom on a hover line stripped. The lake is low and weedy so pick your spots carefully with that method. 
The Lower Lake is too warm to safely catch and release fish unless you go early AM. Otherwise just don’t fish that water as it is reaching 72 in the afternoon and evening and that is lethal. Upper lake and channel holding in lower 60’s and thank you to FFP guide Troy for pointing that out and drawing attention to this.