datoid

March 1990 recorded a temperature anomaly of 0.80°C, marking a 4.2 standard deviation spike above the 60-month average of 0.27°C. This represents the most extreme temperature deviation in the recent data series. The spike coincides with atmospheric CO₂ reaching 431 ppm (up 0.6% in 3 months) and occurs during a period of strong economic activity - GDP grew 1.4% quarterly while unemployment hit record lows at 4.3%. What's notable is how this temperature extreme emerges from relatively stable anomalies in the 0.12-0.44°C range throughout 1988-1989.