Sydneysiders set for sweltering week

High temperatures across NSW have prompted a severe fire danger warning for the Riverina while Sydney is expected to swelter through the week.

Sydneysiders are in for a sweltering week with temperatures set to top 40 degrees in the city's west.

A top of 36 degrees is expected in Sydney on Wednesday and while a cool southerly change in the evening is expected to bring some relief, temperatures will continue to climb to up to 41 degrees in the city's west later in the week.

Further inland, the Bureau of Meteorology has issued a severe fire danger warning due to dangerous fire conditions on Wednesday in the Northern Riverina, with temperatures predicted to reach 40 degrees, humidity at 10 per cent and 30km/h winds.