What climate and soil suit oregano and can I grow it in the plains in summer?

Oregano is a Mediterranean perennial that does best in warm but not extreme heat, full sun, and light well drained soil with pH around 6 to 8. It thrives in milder and hill climates and in the cooler, drier months of the plains. In the plains it can handle warmth, but peak summer above the high 30s combined with poor watering stresses it, and the bigger problem is monsoon humidity, which brings fungal issues and root rot in heavy wet soil. So you can grow it in the plains, but plan around the seasons: the cooler dry months give the best growth and oil-rich leaf, while in peak summer give it some afternoon shade and steady but not excessive water, and in the monsoon ensure sharp drainage (raised beds or pots) and good airflow. It is drought tolerant once established and dislikes constant wet feet far more than it dislikes heat. Propagate from cuttings or division for true plants. If you are in a hot humid high-rainfall area, growing oregano in raised beds or containers you can manage through the monsoon gives far better results than open heavy ground.