Peak irrigation in Asia is often associated with rainy seasons and climate change. Specific irrigation seasons vary by region, but here are some common ones:

1. South Asia (India, Bangladesh, Pakistan, etc.): The main rainy season in these areas is usually summer, which starts in June and lasts until September. During the rainy season, when there is more rainfall, farmland is usually able to rely on natural rainfall for irrigation. Therefore, irrigation activities in these areas peak during the rainy season, especially in areas with insufficient rainfall.

2. Southeast Asia (Indonesia, Philippines, Thailand, etc.): These areas also usually have a distinct rainy season, which starts in May or June and lasts until October. Irrigation activities may be more active in the early or late rainy season to provide enough moisture to the fields when rainfall is insufficient.

3. China: China has a vast territory, and different regions have different irrigation seasons. The rainy season in southern regions usually starts from April or May and lasts until September, and irrigation activities may be more frequent during this period. The northern region has a shorter rainy season, starting in June or July and continuing until August, when irrigation activities are more concentrated.

4. Middle East: The Middle East has a dry climate with relatively little rainfall. In these areas, irrigation often relies on artificial water sources such as rivers, lakes and groundwater. Therefore, irrigation activities may be active during multiple months of the year.

It is important to note that with climate change and evolving water management techniques, irrigation seasons may change. In addition, the water requirements of different crops also affect the timing and frequency of irrigation.