According to the World Meteorological Organization, how many years of data are required to calculate a climate record?

The World Meteorological Organization (WMO) recommends a period of 30 years of continuous data to establish a climate record. This duration is considered sufficient to account for natural variability in climate patterns and to identify trends that are indicative of long-term changes.

A 30-year timeframe balances the need for a comprehensive dataset to understand climatic conditions while being long enough to mitigate the influence of short-term anomalies such as El Niño or other oscillations that may distort interpretations if shorter periods were used. The 30-year standard has become a widely accepted benchmark globally, underpinning many climate studies and assessments.

The options suggesting shorter or longer durations do not capture this median effectively; hence, they do not align with the established guideline by the WMO for climate records.