[question] Is there a weather boost in a specific boosted biome multiplier?

I have been poke hunting up near San Fransisco Piers along the embarcadero(a water biome) for a couple months pretty regularly. In that time, I have occasionally seen Lotabs, but nothing especially common. Yesterday was the first time the game said it was raining(it wasn't but that's beside the point), so water mons were boosted. For the first time I saw 30-40 Lotads about.

I am curious if there is a multiplier effect when the biome is the same as one of the boosted types? Or is this just an effect of water being the theme of the month with Suicune?