Thought your morning commute was damp? Your day (and night) is going to get a lot wetter and windier.

With light to moderate showers already falling over most of the city, Sydney is expected to receive heavy rainfall today. Showers are forecast for the rest of the week, too.

The Bureau of Meteorology (BoM) expects up to 45 millimetres of rain to hit the city, with rainfall and wind gusts expected to intensify. The national weather forecaster is warning Sydneysiders to “prepare for a particularly wet evening commute”. The heavy rainfall is expected to continue until Friday morning.

BoM has also predicted wind speeds to peak at 41 kilometres per hour at around 4pm today.

To put this in perspective, on average, Sydney receives 76.4 millimetres of rainfall during October. With up to 45 millimetres of rain expected today, the city could receive more than half of its monthly rainfall in just 24 hours.

"The wettest period for Sydney, the most intense rainfall [will be] from the late afternoon today into sometime tomorrow morning," senior meteorologist Robert Taggart told the Sydney Morning Herald.

The BoM has predicted a 50 per cent chance of showers falling over the weekend, with up to 10 millilitres of the wet stuff expected on Saturday, then becoming light by Sunday evening. Showers and light winds are forecast next week.

Sydney Trains has already issued a warning for commuters to “slow down” in the wet weather to avoid slips and falls on trains and railway platforms. This morning, a train requiring repairs at Hurstville caused delays on the T2, T3 and T4 lines. The delays were exacerbated by extended boarding times due to wet weather.

So far, there appears to be no major flight disruptions at Sydney Airport.