Weather occurs primarily due to air pressure, temperature and moisture differences between one place to another. These differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics.

Almost all familiar weather phenomena occur in the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and does affect weather lower down in the troposphere, but the exact mechanisms are poorly understood.

The Sun and the weather. The energy that the Earth receives from the Sun is the basic cause of our changing weather. Solar heat warms the huge air masses that comprise large and small weather systems.

Fog is a natural weather conditions that can cause visibility to become zero. First it is important to understand that fog is basically a cloud on the ground. This means like clouds it is a collection of tiny water droplets formed when evaporated water is cooled. The way it is cooled determines how fog is formed.

Weather on Earth is caused by heat from the sun and movement of the air. The amount of moisture in the air affects how clouds form and whether the clouds produce fog, rain, or snow, as well as extreme weather, such as storms and blizzards.

In terms of immediate danger, destruction, and threat to lives, tornadoes are considered the most deadly weather phenomena. In terms of total fatalities measured over time, drought and flooding are by far the most deadly and devastating.

These 30 Places Have the Worst Weather in America

• Buffalo, New York. 24/31.
• Portland, Oregon. 25/31.
• Tampa, Florida. 26/31.
• Jacksonville, Florida. 27/31.
• Houston, Texas. 28/31.
• Orlando, Florida. 29/31.
• Los Angeles, California. 30/31.
• Lubbock, Texas. 31/31.

North Dakota

Here are the five worst U.S. states (plus one not-state) to consider visiting:

• District of Columbia (35 percent of matchups)
• Alabama (38 percent of matchups)
• Mississippi (38 percent of matchups)
• New Jersey (39 percent of matchups)
• Arkansas (39 percent of matchups)
• Iowa (39 percent of matchups)

Alaska

The rest of the world’s coldest places are at the north end of the planet. The second coldest place in the world also sits at the top of a massive ice cap, this time in Greenland. For the coldest places located on exposed dirt, northern Canada and eastern Siberia top the list.

Phoenix

Portland, Maine is in or near the cool temperate wet forest biome whereas Chicago, Illinois is in or near the cool temperate moist forest biome. The average temperature is 3.1 °C (5.5°F) cooler. Average monthly temperatures vary by 1 °C (1.8°F) less in Portland, Maine.

Vostok station, Antarctica This place is famous for being home to the coldest temperature ever recorded on earth – a mind numbing -89.2°C.