The flowers are out in full force, like this mountain butterweed (Senecio integerrimus). It's newly recognized common name is lambstongue ragwort. Sorry, but that's just not a good name for such a pretty flower!
Upon closer inspection I can see some flowers hiding out among the three-leaved clover. This is a native species of clover, hollyleaf clover (Trifolium gymnocarpon).
Another good indication that it's warmer is that the creeks are rising fast. The one above is a tributary that usually looks like it has a trickle of water going over that log.
Here's a link to a different creek not too far away that shows how it's gone from 1 cubic foot per second (cfs) to 15 cfs in about a month's time: Lehman Creek gage. It will get even higher before it peaks.
Summer's coming, ready or not!