I don't think it's necessarily the temperature, although I'm sure it's part.
They bloom in early summer in nature. Day length is longer, it's hot in their habitat and it's around the monsoon season, so lots of rain. All these are cues for them to know when to flower I think.
Horticultural varieties differ in their blooming habits.
Some bloom every year around summer like they should
and some bloom more than once a year, and some do not bloom every year.
Your temperature range for now is about early spring weather for neos I think.
I don't know the habit of your particular neos, but for regular variety, they won't flower under such low temp.