Mean Monthly Temperature Records Across the Globe

Overview

The mean monthly temperature records product provides historical perspectives on the occurrences of warm or cold mean monthly temperatures across the globe from the gridded (5° latitude by 5° longitude) NOAAGlobalTemp. On a monthly basis, the percentage area of the globe experiencing record warm or record cold conditions is reported as a time series for the month from 1951 to the present, complementing the percentile maps, but choosing a start date with relatively uniform and broad global coverage. In addition, the ratio of warm-to-cold records is plotted as a time series. For example, a ratio value of 2 indicates that the global area experiencing record warm mean monthly temperatures over the most recent month was 2 times larger than the global area experiencing record cold conditions.

January 2024 Global Land and Ocean

Timeseries of Global Land and Ocean Areas at Record Levels for January from 1951-2024

Timeseries of Ratio of Warm Records to Cold Records for January from 1951-2024

During January 2024, 12.3% of the world's surface had a record-high January temperature, exceeding the previous record set in January 2016 by 2.5%. Across the global land, 7.3% of its surface had a record-high January temperature. Across the global ocean, 14.6% of its surface had a record-high temperature for the month. Meanwhile, 0.9% of global land and ocean surface experienced a record-cold January temperature.

Timeseries of Global Land Areas at Record Levels for January from 1951-2043

Timeseries of Global Ocean Areas at Record Levels for January from 1951-2024

Monthly data for these plots may be accessed via the links below and are formatted in columns by data type with the following labels:
Year    Month    Ratio    %AreaRecordWarm    %AreaRecordCold

• Combined land and ocean surface
• Land surface
• Ocean surface

Methodology

Only grid cells that are completely free of missing values from 1951-present are utilized in the analysis, generally limiting our domain to 45°S to 75°N. For each retained grid cell, the warmest and coldest mean monthly temperatures in the 1951-present period of record are identified for each month. These monthly records are expressed as percent areas aggregated over 3 spatial domains: global land-only areas, global ocean-only areas, and the combined global land and ocean. The spatial aggregation accounts for differences in grid cell size with latitude (i.e., cosine weighting) as well as the fraction of land and ocean areas within coastal grid cells. Monthly ratios are computed by dividing the areal extents experiencing warm records with the areal extents experiencing cold records. For seasonal and annual aggregations, the warm and cold record areal extents are summed separately before dividing the totals.

• Ratio values between 0.8 (five-to-four) and 1.25 (four-to-five) are shown in gray.
• Red circles indicate values above 1.25.
• Blue circles indicate values below 0.8.
• Dark red (dark blue) values represent one of two things:
  • A ratio value that is greater than 50 (less than 0.02)
  • An observation in which the warm (cold) record area is non-zero and the cold (warm) record area is zero.
• In rare cases, the warm and cold record areas are both zero, in which case the value would be shown as a dark gray circle over unity (i.e., a value of 1).