In Mexico, summer temperatures average from 70-90 degrees Fahrenheit (21-32 Celsius) during the day, and drop to around 60 or lower at night. The humidity can make these temperatures feel much higher though. Rainfall is more likely in the coastal areas of Mexico during the summer months, so it's best to pack a light raincoat for your trip. In the higher altitudes and mountainous regions, temperatures can drop much lower than in coastal areas.