RewriteEngine On
RewriteRule ^index\.html$ index.php [QSA,L]
RewriteRule ^(index|weekend|citychange|near)_([0-9]+)\.html$ index.php?act=$1&id=$2 [QSA,L]
RewriteRule ^forecast(3|10)_([0-9]+)\.html$ index.php?act=forecast&id=$2&mod=$1 [QSA,L]
RewriteRule ^search\.html$ index.php?act=search [QSA,L]
RewriteRule ^citylist_(oth|su|ru)_([0-9]+)\.html$ index.php?act=citylist&id=$2&mod=$1 [QSA,L]