Sun light on sour dough starter I have left my sour dough starter on the North facing window during the day.(I live in Australia)
It has been exposed to warm, direct sunlight.
Have I killed my wild yeasts?
Should I start again?
I have seen little to no activity.
The starter is 4 days old.
It's hard to say, not knowing the exact temperatures reached in your starter.  I would move so that it no longer is in the sun, and continue to feed for a couple of days to see if it has any life.