Why does Postgresql say "schema does not exist" -

how can query work?

select weather.id, cities.name, weather.date, weather.degree weather join weather.city_id on cities.id weather.date = '2011-04-30'; 

error: schema "weather" not exist.

weather not schema, it's table!

perhaps:

select weather.id, cities.name, weather.date, weather.degree  weather join cities on (weather.city_id = cities.id) weather.date = '2011-04-30'; 

postgres complaining join on weather.city_id interpreted table/view called 'city_id' in schema 'weather'