PACIFIC GROVE, Calif. -- Tens of thousands of monarch butterflies are back on the Central Coast. It's that time of year when they come to escape the cold winters of the northwest.
Researchers said the butterflies know they can't survive the winter anywhere else, so they move within two miles of the ocean.
But they said this year we aren't seeing as many.
In Pacific Grove, there are about 10,000 this year, and about 30,000 in the Pismo Beach area.
Researchers said back in 1990, there were hundreds of thousands.
Monarch groves said there are many theories as to why we aren't seeing as many, but weather plays a huge factor.
The butterflies are after milkweed, a plant they lay their eggs on, so if there is a drought, there are less plants, so they might not come.
And if it's too cold, they won't make their way here because they could freeze to death.
The monarch butterflies will be on the Central Coast through February.
The next generations will move on to the north and east to find more milkweed, before they make their way back here next year.
