Global temperature anomalies in April 2010 (top) compared to the 1971-2000 average. Trend in April temperatures from 1880 to 2010 compared to the 1901-2000 average (bottom graph). The color and size of the dots show the direction of the anomaly (blue is colder than average, red is warmer than average) and its magnitude (larger dots mean larger differences from average).  Based on Global Historical Climatoogy Network data from the National Climatic Data Center.