My house appreciated 30% in the last 30 days according to Zillow

[Angel Moreno]

I purchased my first home exactly one year ago at a price of $55k. Today on Zillow it is estimated at 80k with a 30% appreciation in the last 30 days. How accurate can that be? And if is accurate should I sell or continue to hold. I plan to rent out for 1000 a month in the next couple months leaving me with a $300 cash flow a month.