What causes the northwest wind and southeast wind to form in Australia in July and 1 month respectively?

The seasons in July and 1 month in Australia are opposite, because Australia is located in the southern hemisphere and the seasons are opposite to those in the northern hemisphere. January is summer and July is winter.

In Australia, the southeast wind formed in 1 month is mainly because the low pressure belt near the equator makes the airflow in the southern hemisphere move to the southeast. Under the influence of these air currents, a southeast wind formed in January. The northwest wind mainly formed in July, because the pressure system in the southern hemisphere changed, and the subtropical high spread southward, forming a huge stable high pressure area, which inhibited the movement of the atmosphere and formed relatively dry weather. At the same time, due to the influence of the north wind, a northwest wind has formed in southern Australia.

It should be noted that the meteorological situation in Australia is very complicated, and the above explanation is just one of them. In fact, there are other complex meteorological system effects.