TOKYO, April 6 (Reuters) - Japan's Nikkei share average fell to the lowest level since mid-January in early trade on Thursday as weak Wall Street performances soured sentiment, while a stronger yen pressured the overall market.

The Nikkei dropped 1.0 percent to 18,668.90, the lowest since Jan. 18. If it falls below 18,650.33 hit on that day, it would be the lowest since early December.

The broader Topix declined 1.0 percent to 1,489.35 and the JPX-Nikkei Index 400 shed 1.0 percent to 13,334.08. (Reporting by Ayai Tomisawa)