sql server - Collation conflict with temp table -

the collation of tempdb latin1_general_100_ci_ai. collation of database latin1_general_100_ci_ai. yet following sql statement:

select * ##citiesmapping cm inner join cities on cm.cityname=cities.name 

returns:

cannot resolve collation conflict between "sql_latin1_general_cp1_ci_as" , "latin1_general_100_ci_ai" in equal operation. 

the server default collation latin1_general_100_ci_ai

check tables involved well:

select name, collation_name, object_name(object_id) sys.columns  object_name(object_id) in ('cities')