Air temperature
Some of the factors influencing air temperature are solar radiation, latitude, surface reflection, the in/outflow of air masses and the distribution of land/water. Solar radiation and latitude are the most influential factors.

The twelve-monthly temperature cycle shown in figure 1 reflects the normal variation in incoming solar radiation over the course of a year. In high latitudes the seasonal difference in solar radiation is the most extreme. Radiation varies from zero in midwinter to a maximum of around 350 - 400 W/m2 in summer.

Figure 1: The annual cycle of global radiation (brown line) and surface air temperature (blue line) at a grid cell location in the central Beaufort Sea. Values were drawn from the Arctic Meteorology and Climate Atlas gridded fields for global radiation and two-meter air temperature.	Figure 2: Surface air temperature over the course of a day (data from drifting station NP-30). Brown: Temperature on the day of the summer solstice, under constant sunlight. Light blue: Temperature at the spring equinox. Diurnal variation is clearly visible. Dark blue: Temperature on the day of the winter solstice, under constant darkness.

High latitude and low levels of solar radiation combined with a high reflectance results in low temperatures. However, much of the Arctic is ocean or in the vicinity of the ocean. Lands closest to the ocean have a marine climate with more moderate temperatures than continental regions. Temperature varies widely from place to place across the Arctic. Local topography and transport of warm or cold air over a region, cause local variations in temperature.
Over the course of a day air temperature usually rises from an early morning minimum to an afternoon maximum. This typical pattern can change if an inflow of cold air occurs during the same period. Depending on how cold the incoming air is, air temperatures may climb more slowly than usual, may remain steady, or may even fall during daylight hours. Air temperatures may climb through the evening hours as a consequence of strong warm air inflow or by increasing cloud cover.
A daily pattern of rising and falling air temperature is the case during the period of the year when the Arctic receives sunlight. Diurnal temperature variation is most obvious around the spring, when the differences in solar radiation from day to night are largest.
The figure shows the daily cycle of temperatures at three times of the year, using data from a Russian drifting station in the central Arctic Ocean. Note the near-constant temperature of 0 degrees Celsius in midsummer. On land, solar radiation is absorbed by soil and re-radiated as heat, but in the Arctic Ocean, energy from solar radiation is spent melting ice and snow, and the air temperature stays near freezing. During polar darkness, when solar radiation is not present, air temperature is mainly controlled by cloud cover. It tends to be colder under clear conditions and warmer under cloudy conditions. In/outflow of warm or cold air, however, can change these relationships.

Water temperature
The Arctic Ocean is contained in a polar climate characterized by persistent cold and relatively narrow annual temperature ranges. The temperature of the water near the surface is fairly constant, near the freezing point of seawater, slightly below zero degrees Celsius.