Some Nassau homeowners are getting slammed with steeper than expected school tax hikes.

School tax rates are going up an average of 6.8 percent from last year, according to Newsday. That number is more than double what homeowners thought they approved in school budget votes back in May. In some cases, the rate increases are more than twice as high as expected.

Analysts believe the increases are the result of successful property assessments. In Nassau County, 87 percent of property owners won and got a reduction.

Nassau County is one of the only counties in the country that is responsible for assessing property. In Suffolk, the towns are in charge of assessing property values.