Look out a window. Do you see blue skies? Maybe you spot dark rain clouds or, perhaps, leaves are being blown by a strong wind. The conditions on Earth—such as the temperature, level of storminess, and the amount of rainfall—all define our planet’s weather.

Earth’s weather is linked to the seasons: winter, spring, summer, and fall. The planet experiences seasons because its axis of rotation is tilted, which results in different intensities of sunlight hitting Earth over the course of a year in a given location with the exception of the equator. It’s generally colder in the winter, and summertime brings higher temperatures.

Weather on Earth is extremely varied. Some places, like deserts, tend to be hot and dry. Snow often falls on high mountains—snowfall can accumulate slowly over time or rapidly during a large blizzard.

Some types of weather can be dangerous: Extremely hot conditions can cause dehydration and heatstroke, and freezing temperatures can make it difficult to stay warm. Scientists who study the weather—meteorologists—are constantly trying to better predict weather patterns. These scientists often use supercomputers to simulate Earth’s weather. Knowing what type of weather is coming in a few hours, days, or weeks can help people prepare for changing conditions by getting to shelter, getting clothes, or purchasing supplies, such as water, bread, batteries, and even sunscreen.

Earth’s weather generally depends on the temperature, air pressure, and moisture level. Earth’s atmosphere, which is where weather is produced, is large and complex. It’s therefore quite difficult, if not impossible, to control the weather. However, that fact hasn’t stopped people from trying. One form of trying to control the weather is called “cloud seeding,” which involves launching small particles into clouds to create rain or snowfall. Whether cloud seeding works is hard to prove since conducting experiments on weather are notoriously difficult.

Weather also exists on other planets. Mars experiences dust storms and the Great Red Spot on Jupiter is a storm larger than Earth, which has existed for at least 300 years.