Six month old with a fever of 103.1 out of nowhere

My daughter just turned six months on 10 June and she has been a little fussy and clingy today and yesterday but out of nowhere literally around 4 o’clock it’s only 5:03pm here where I am at in California she broke out with a fever of 103.1 we put her in the shower and gave her medicine to help her fever go down and now she is asleep on my shoulder she still feels very clammy and I just don’t understand where the fever came from

It is now 510 almost one hour since she had fever of 103.1 it is now 100.7