Summer in the southern hemisphere causes the most weather activity on Mars.
The temperature increase shrinks the southern polar ice cap, at the same time, the northern ice cap, experiencing winter, grows larger, which increases the air pressure.
Increased air pressure causes severe winds to blow toward the equator.
The winds can reach up to 90 miles (150 km) per hour, which results in widespread, even planet-wide, dust storms that last up to 6 months.
