Cat Bay Weather Forecast
- 11
- 19
Rain increasing
- 11
- 19
Possible shower. Wind easing
- 11
- 18
Shower or two. Wind easing
- 11
- 19
Shower or two. Windy
- 11
- 17
Cloudy
- 11
- 17
Cloudy
- 11
- 22
Sunny
Today 21 Dec Central
Cloudy. The chance of fog in the southeast early this morning. Very high chance of rain. A thunderstorm likely during the morning and afternoon, possibly severe with damaging winds, large hail and heavy rain which may lead to flash flooding. Winds east to southeasterly 15 to 20 km/h shifting southwesterly 20 to 30 km/h in the early afternoon. Daytime maximum temperatures between 19 and 23.
Western Port Local Waters
- Wind
- East to southeasterly about 10 knots tending southeast to southwesterly 15 to 20 knots in the middle of the day then tending southwesterly in the late evening. Winds reaching up to 30 knots west of Sandy Point in the evening.
- Seas
- Below 1 metre, increasing to 1 to 1.5 metres west of Sandy Point during the afternoon.
- Weather
- Cloudy. 90% chance of rain. The chance of a thunderstorm this afternoon.
- Weather Situation
- A low pressure system south of the Bight will move east and combine with a broad trough over western Victoria early Sunday. The low pressure system will then deepen and slowly move southeast across the State during Sunday to clear into eastern Bass Strait late Sunday. A high pressure ridge then builds across Victoria and Bass Strait during Monday. A weak cold front crosses Bass Strait during late Monday and early Tuesday with the ridge re-establishing itself from Tuesday to Thursday.
Cat Bay Temperature Statistics View More
December Temperature
Rhyll (14km)
Lowest 7 December, 2025
8.6 °CAverage December
16.8 °CHighest 18 December, 2025
35.3 °C
Climate (2020–Present)
Rhyll (14km)
Average Low 2020–2025
12.1 °CAverage 2020–2025
15.1 °CAverage High 2020–2025
19.2 °C