How Climate Works
Since climate information is really just the average of weather conditions over a given period of time, all you have to do is use numbers to describe the weather you see and feel every day! You make an average by adding up numbers, then dividing them. Here is a short example using daily high temperatures for 5 days:
Monday’s High: 81º
Tuesday’s High: 83º
Wednesday’s High: 70º
Thursday’s High: 66º
Friday’s High: 72º
* Add the high temperatures from all five days together, and the sum is 372º.
* When you divide the sum of the high temperatures by the number of days (5), you get 74.4º.
Average Weather Means...
Average temperatures, rainfall, snowfall, and other weather details help us understand what the weather is generally like in an area during a certain time of year. You know from your own experience that it’s cooler in the Fall and Winter seasons than Spring and Summer. With averages we can see just how much warmer or colder the weather is here in Alabama from season to season and from place to place!
The Alabama Climate Comparison!
Things That Shape Your Climate
There are three main factors that influence a particular location's climate.
* Latitude
* Altitude
* Continentality
Latitude
Latitude may be one of the most important factors in how your climate works, and it is easy to see why. The Sun is the main source of heat and energy for our planet, so the more sunlight you see, the warmer the weather should be, right?
That’s where latitude comes into play. Low latitudes (near the Equator, or 0º Latitude) see the most direct sunlight. High latitudes (near the poles, or 90º North or South Latitude), see the least amount of direct sunlight. The Earth’s tilt and revolution around the Sun cause our seasons, and latitude has a big role in how seasons change where you live.
ABC 33/40 Student Weather Center’s Sun & Seasons Page
NASA’s EarthKAM Map Skills Page
Low latitudes (closer to 0º Latitude) are usually warmer, and high latitudes (closer to 90º N Latitude) are normally colder.
Altitude
On clear, calm, cold mornings in Alabama, the altitude of a city or community makes a big, big difference in what the temperature is. Some mornings, the temperature at the state’s highest point, Mount Cheaha, may be as much as 25 degrees warmer than Anniston or Talladega. The reason is that Anniston and Talladega sit about 1,500 feet below Cheaha’s peak. On a cold, clear morning, a temperature inversion develops leaving very cold temperatures in low valleys and warmer temperatures on the mountains! It is called an inversion because normally the temperature gets colder the higher you go into the sky. Inversions are just the opposite of that!
The above map shows different colors for elevation changes in Alabama. Click here for a more detailed map with a scale.
In the summertime it is different. Cheaha may be as much as 10 degrees cooler in the Alabama Summer because it is higher up. When there is not an inversion, Cheaha will be cooler than Anniston and Talladega because temperature normally falls as you go higher up into the atmosphere.
Continentality
Continentality is a big word that explains how much land surrounds you. Huntsville and Birmingham are much farther from the ocean than Montgomery and Mobile. That means Huntsville and Birmingham are surrounded by land, and the ocean does not has as much influence. In Mobile and Montgomery, the ocean has a bigger influence on the climate because they are closer to the water!
This really comes into play with rain and temperature patterns across the USA. Places like Kansas City, Missouri are about as far from the ocean as you can get! Because of that, they have less rain than cities in Alabama that are closer to the ocean.
Bonus Effects! Geographical Features play a role in our climate as well:
Mountains, hills, soil types, trees, lakes, and oceans are just a few of the natural geographical features that influence our climate. Areas with a lot of trees and grass stay cooler in the summertime than flat, rocky ground. Lakes and oceans keep the weather cooler in the summer and warmer in the winter than other places.
Man-made features inside cities can change the climate in a small area. When a city like Birmingham heats up during the day, it does not cool down as quickly as smaller towns and rural areas nearby. The buildings and streets absorb a lot of heat on a sunny day, and they cool down slowly overnight. Rural parts of Alabama cool down faster because trees and grass release heat quickly. The city’s unusual warmth is called the “Urban Heat Island.”
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