Near-Surface Air Temperatures

About this map

This interactive map shows average monthly surface air temperature anomalies in the Arctic. Temperatures are measured at 2 meters (about 6 feet) above the Earth’s surface. A different map is available for every month of every year in the time series.

Each monthly map shows how surface air temperatures compare to long-term average temperatures for that month over the period of 1979 to 2015. The corresponding bar graph shows how much the overall surface air temperature for that month departs from the long-term average.

Color key and bar graph

When you select a month on the dropdown selector and a year on the lower-left slider, the map will show surface air temperatures.

• Higher-than-average surface air temperatures will appear in shades of orange and red, and areas with lower-than-average surface air temperatures will appear in shades of blue.
• Areas with temperatures at or near the long-term monthly average are white or nearly white.
• The greater the temperature departure from average, the darker the color.

The bar graph indicates the temperature anomaly (departure from the long-term average) for the entire Arctic. Blue bars indicate negative anomalies (years in which temperature is less than the long-term average) and red bars show positive anomalies (years in which temperature is greater than the long-term average). The bars show every year in the time series for the selected month, and the bar that correlates with the map on display is highlighted in light gray.

Although each month has areas with above-average and below-average temperatures, the bar graph shows the overall departure from the long-term average for that month, for the whole region from 60°N of the equator to the North Pole.

How to change the display

• To change the month displayed on both the map and the graph, use the month dropdown selector in the bar graph box (lower right).
• To change the year displayed, move the slider in the year box (lower left). 
• To animate the time series for the selected month, click the play arrow. The animation will display maps for the selected month for all years in the time series.

Why Arctic surface air temperatures matter

Surface air temperature has a profound effect on land, water, wildlife, and people. That is true across the globe, and particularly in the Arctic. People often think of the Arctic as a perpetually frozen place, but the snow and ice in the Arctic actually exist fairly close to their melting point. Raise the temperature high enough and for a long enough period of time, and those icy bodies will turn to water.

Besides being the home of plants and animals that thrive in very cold conditions, the Arctic functions as Earth’s built-in air-conditioning system. The Arctic’s vast stretches of snow and ice reflect most of the sunlight reaching them back into space which creates a cooling effect. Meanwhile, the Arctic’s frozen ground locks carbon-rich material underground, also keeping it from warming the atmosphere. These functions help regulate global climate. So long as Arctic surface air temperatures remain low, the planetary air conditioner keeps working. If surface air temperatures rise significantly, the air conditioner stops working, or at least stops working as effectively.

So although the Arctic may seem remote, what happens there can matter anywhere.

What the data show

Shifting Arctic temperatures are both a measurement of change, and a driver of future changes. Scientists have monitored Arctic surface air temperatures for over a century, and satellites have provided continuous surface air temperature observations for decades.

As reported in the Arctic Report Card: Update for 2020, Arctic surface air temperatures have risen roughly twice as fast as global surface air temperatures since the year 2000. This trend is known as Arctic amplification: more intense warming in the Arctic than over the rest of the globe, and it is consistent with climate-model projections of global warming.

Multiple factors contribute to Arctic amplification, including heat transport to the Arctic through atmospheric and oceanic circulation, reduced snow cover, and sea ice loss. Sea ice retreat exposes bigger areas of dark, heat-absorbing ocean water to sunlight, and the ocean gains much more heat each summer. In turn, more heat is released back to the atmosphere in autumn as sunlight wanes. In fact, autumn warming has been strongest in areas that have shown the greatest declines in summer sea ice extent.

By viewing different months and years, you can use this map to see how surface air temperatures change over time and where temperatures are changing in the Arctic. You may be able to detect patterns in these changes. Try using these maps to answer questions such as:

• When are above-average temperatures more common? When are below-average temperatures more common?
• What times of year and which years show the biggest departures from the long-term average?
• Do unusually warm or cold temperatures happen in the same places year after year or month after month?
• Is an above- or below-average temperature for the entire region mostly driven by temperature anomalies over large areas, or by intense temperature anomalies over small areas?

By comparing surface air temperature maps with other maps in Satellite Observations of Arctic Change, you can see how surface air temperature relates to changes in other parts of the Arctic ecosystem, such as sea ice concentration, snow cover duration, and non-frozen ground.

These surface air temperature maps have been assembled by combining weather-forecast models with observations of atmospheric pressure, air temperature, humidity, and wind speed. The observations come from multiple sources: satellites, aircraft, balloon-borne instruments and weather stations. 

Data source(s)

The data shown here are from the NASA Modern-Era Retrospective analysis for Research and Applications (MERRA) reanalysis project. To cover gaps in regions where surface observations are sparse, which has historically been true of the Arctic, reanalysis "predicts" the weather of the past. Combining observational weather records with short-term forecasts from models produces estimated temperatures from previous years and decades. Although no reanalysis product is perfect, estimated temperatures for the Arctic are consistent with ground-station observations.

Explore the source data for this map:

Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavgM_2d_slv_Nx: 2d,Monthly mean,Time-Averaged,Single-Level,Assimilation,Single-Level Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), doi:10.5067/AP1B0BA5PD2K

Data processing steps

Quick links

Arctic Sea Ice News & Analysis

Arctic weather and climate