I have city sewer, I have a awful sewer smell , generally on warm days emitting from the bathroom when the winter came the smell went away so I thought it was gone this weekend was 60 the smell is back.. I ran bleach through the toilet, I need to check the pipe on the roof... other than that what could the smell be.

Well the same happened to me before nasty used toilet water backed up through the drain in my laundry room. Mabey for you it is just a smell, but I would definitely get the pipes checked by, like a plumer or something.