It is important to restrict the access to your WordPress admin area only to people that actually need access to it. If your site does not support registration or front-end content creation, your visitors should not be able to access your /wp-admin/ folder or the wp-login.php file. The best you can do is to get your home IP address and add these lines to the .htaccess file in your WordPress admin folder replacing xx.xxx.xxx.xxx with your IP address:
Deny from all
Allow from xx.xxx.xxx.xxx
In case you want to allow access to multiple computers (like your office, home PC, laptop, etc.), simply add another Allow from xx.xxx.xxx.xxx statement on a new line.
If you want to be able to access your admin area from any IP address (for example, if you often rely on free Wi-Fi networks) restricting your admin area to a single IP address or to few IPs can be inconvenient. In such cases we recommend that you limit the number of incorrect login attempt to your site. This way you will protect your WordPress site from brute-force attacks and people trying to guess your password. For such purposes, you can use a the plugin called WP User – Limit login attempts.