I have been 3 times in February. The weather has been variable though we have always ended up in shorts/teeshirts sometimes long sleeves/trousers required. Temperatures are like a Spring or a Summer day here.
Crowd levels were fine, busier during the President's Day week (but good sales on then).
Warm enough to go to the water parks.
Fireworks shows are on just the same as the rest of the year.