Uptown bidding wars drove the average resale value of Manhattan homes to a record level last month, a report released by StreetEasy revealed Wednesday.

The listings site found that neighborhoods like East Harlem, Hamilton Heights and Inwood led the borough's 6.3% jump in resale prices from $924,936 in July 2014 to $983,207 last month. This marked the highest Manhattan resale price in the 20 years StreetEasy has collected the data.

Competition for apartments from buyers priced out of other areas in the borough and in Brooklyn are creating bidding wars that are driving up closing prices, according to StreetEasy data scientist Alan Lightfeldt.

"With home buyers being priced out of not only Manhattan but many Brooklyn neighborhoods as well, these northern neighborhoods are attractive now more than ever," he said in a statement.

Upper Manhattan properties sold for 1.4% above their asking prices in July, according to the report. The competition for apartments is expected to get even more intense as the market adjusts to a 5.1% shrink in inventory between July 2014 and 2015.

Brooklyn resale prices also soared in the last year, from $497,788 in July 2014 to $524,171 last month, a 5.3% jump. Although the borough's co-op inventory was down 10.9% year to year, overall apartment inventory was up 6.3% during that time period, according to StreetEasy.