From NOAA March 2023 Global Climate Report:
March 2023 was the second-warmest March for the globe in NOAA’s 174-year record. The March global surface temperature was 1.24°C (2.23°F) above the 20th-century average of 12.7°C (54.9°F). March 2023 marked the 47th consecutive March and the 529th consecutive month with global temperatures, at least nominally, above the 20th-century average. The March 2023 temperature anomaly was the third highest for all months, after March 2016 and February 2016.
Global land-only temperatures ranked second warmest on record at 2.26°C (4.07°F) above average. Ocean-only temperatures ranked third-warmest on record for March, which is an important item to note as the long-lived La Niña ends. On March 9, NOAA’s Climate Prediction Center announced the end of the three-year La Niña, as well as a return to neutral El Niño Southern Oscillation (ENSO-neutral) conditions likely through Northern Hemisphere spring and early summer 2023.
Data is available at the top of the page.