October is the start of the rainy season in Bali. Normally the rainy season will last for six months from October to April. Meanwhile, the dry season is from April to October.
Actually it does not rain every day during the rainny season. In fact, rain will usually start on December or January. So, there is no need to worry the rain will spoil your holiday if you are planning to visit Bali.
So far there is no rain today in Bali. Even the weather is hot. It's about 29 degree Celcius with some clouds in the sky.
Many adventures activity can be enjoyed during the rainy season, especially white water rafting or kayaking. Maybe it is not good time for shopping, because the street will be wet and muddy in the traditional markets.