Monthly mean is a figure computed by adding the daily means for each day of the month and dividing by the number of days in the month. Annual mean is an average of the 12 monthly means. Annual range is the difference between the warmest and the coldest monthly means.

An isotherm is a line connecting points of equal temperature, so we can visualize temperature distribution over a wide area.

A steep temperature gradient shows temperatures changing rapidly over a short distance.

Temperatures generally peak in early afternoon. Although solar radiation is at maximum at noon and decreases after that time, it continues to provide more energy than is being lost for a few hours. Since the temperature is dependent on the total energy budget (gain versus loss), it continues to rise if there is a surplus. The maximum temperature occurs when solar energy gained no longer exceeds the energy loss. After the maximum is reached, temperatures will continue to fall throughout the night and reach their lowest point usually before sunrise.

Latitude

Water acts as a moderator of temperature, tempering the daily temperature range.

In general, the presence of water moderates temperatures but proximity to a warm or cold ocean current can significantly affect coastal temperatures. 

Generally, higher altitudes experience cooler temperatures and stations located high in the mountains tend to have a greater daily temperature range than do stations at lower elevations.

One example compares Eureka, California and New York City, located at similar latitudes but on opposite sides of the continent. Eureka, on the west coast, is strongly influenced by onshore westerly winds, which act to moderate temperatures throughout the year. New York is influenced by the same westerly winds, which now arrive from the interior of the continent and therefore tend to have more extreme temperatures.

Clouds can block solar radiation and contribute to cooling the Earth’s surface during the day. However, at night they can absorb terrestrial radiation and aid in keeping the Earth’s surface warmer.

Without clouds, clear days are generally warmer and clear nights cooler.

Latitude is the primary temperature control, so the isotherms tend to follow lines of latitude. Since land heats and cools more rapidly than water, isotherms are more likely to bend over land. 

When the temperature changes, the liquid expands or contracts more than the glass. Because of this differential expansion and contraction, the length of the liquid column in the glass tube is a measure of surrounding temperature.

A thermistor operates due to a conductor whose resistance to the flow of current is temperature-dependent. Temperature is therefore indicated as a function of current.

Apparent temperature is the temperature that a person perceives. How warm or cold the air feels depends upon more than just temperature; it can also be influenced by relative humidity, wind, and the amount of sunshine.

Heating degree days and cooling degree days are relative measures that allow us to evaluate the weather-produced needs and costs of heating and cooling. Growing degree days is a basic index used by farmers to determine the approximate date when crops will be ready to harvest.

Windchill is the perceived decrease in air temperature felt by the body die to the flow of air.

The heat stress index combines temperature and humidity to establish the degree of comfort or discomfort. While air temperature and relative humidity are the primary factors taken into consideration, other factors such as the length of exposure to direct sunlight, wind speed, and the general health of the individual can affect the amount of stress a person will experience.