There are lot of reasons why women should not enter the temple and all these reasons are purely based on mythology. Lets talk about these reasons.

Temples are full of positive energy, which helps the humans to heal themselves but when a women enters during that period, it creates imbalance between the energy flow inside the temple.
The flow of energy in the holy place moves in the upward direction, while the women’s energy moves downward during that particular phase.

Temple During Periods

There are some temples, which remain closed during periods in our country. The following names are:

Kamakhya temple, Assam

During Ambubachi festival this Kamakhya temple remain closed for three days to give rest to the goddess, which is believed to be menstruating during that time.

During tullu festival, Keddasa temple in Karnataka also remain closed for three days.
During Raja Parva in Odisha, farmers do not plough their land in order to give some rest to the Goddess Earth.

Here is video: