Data Source & Information

• This page provides time series and map visualizations of daily mean 2-meter air temperature from the NCEP Climate Forecast System (CFS) version 2 (April 2011 – present) and CFS Reanalysis (January 1979 – March 2011). CFS/CFSR is a numerical climate/weather modeling framework that ingests surface, radiosonde, and satellite observations to estimate the state of the atmosphere at hourly time resolution onward from 1 January 1979. The horizontal gridcell resolution is 0.5°x0.5° (~ 55km at 45°N). The daily means are calculated from eight 3-hourly CFS timeslices beginning at 0000 UTC. The chart and maps update each day at about 0500 UTC with CFS estimates for the preceding day. Temperature anomalies are in reference to 1979–2000 climatology for each specific day of the year.


• The time series chart displays area-weighted means for the selected domain. For example, if World is selected, then each daily temperature value on the chart represents the average of all gridcells 90°S–90°N, 0–360°E and accounts for the convergence of longitudes at the poles. Hide or display individual time series by clicking the year below the chart; Hide All and Show All buttons are at the chart lower right. The map below the chart can be updated by clicking a point on one of the time series. The map can be switched between temperature and temperature anomaly by clicking the toggle botton at the map top-left.


• Please note that any apparent record high daily temperature in CFS should be evaluated against other datasets. For long-term global climate time series, refer to NOAA's National Centers for Environmental Information (NCEI) Climate at a Glance with monthly means of surface temperature observations 1850 to present.


• NCAR Command Language is used for data processing and map generation. The interactive time series chart is made using HighCharts. CFS data grids are downloaded daily from the NOAA Operational Model Archive and Data Distribution System (NOMADS).

Last updated 30 August 2023