From NOAA’s Global Climate Report – March 2021:
Following a strongly negative Arctic Oscillation (AO) in February 2021, a strongly positive AO was present in March 2021. In a positive phase, the jet stream strengthens and circulates the North Pole, confining the cold Arctic Air across the Polar Regions. The AO value for March 2021 was 2.11—the fifth highest March value since 1950. The peak value on March 11 was the ninth highest daily value and the third highest for a day in March. In addition, during March 2021, La Niña continued to be present across the tropical Pacific Ocean; however, it weakened in strength.
The global surface temperature departure of +0.85°C (+1.53°F) in March 2021 was the smallest March temperature departure since 2014 and was the eighth highest for March in the 142-year record. March 2021 also marked the 45th consecutive March and the 435th consecutive month with temperatures, at least nominally, above the 20th-century average.
The data is available near the top of the page under Temperature Anomalies Time Series.