Carbon emissions exert great pressure to the environment, and accurate measurement of carbon emissions is significantly important for regional carbon reduction and sustainable development. This study selects six metropolitan areas (MAs) of the Yangtze River Delta urban agglomeration (YRDUA) to measure the energy carbon emissions (ECE) and energy carbon emissions intensity (ECEI) from 2013 to 2022, depicts the spatiotemporal evolution characteristics of ECEI. The results show that: (1) the ECE of the six MAs remained a stable trend while the ECEI showed a downward trend during the study period, and the ECE are not proportional to the ECEI. (2) The ECEI were continuously decreasing, and the ECEI of each MA were converging towards the low value. High ECEI were concentrated in the middle of the six MAs and dispersed in the edges of the six MAs, while low ECEI were concentrated between the middle and the edges of the six MAs. (3) The variation degree of ECEI in different MAs was large in terms of horizontal comparison, and the variation degree in each MA was small in terms of vertical time change. These findings can provide critical policy implications for regional carbon reductions.