Located near the geographic south pole, the 10-meter South Pole Telescope (SPT) has been measuring the anisotropy of the cosmic microwave background (CMB) radiation since 2007. We are currently taking data with the third-generation receiver (SPT-3G), which is a significant upgrade from the previous generation. We successfully completed our 2019 observing season, and our preliminary analysis shows that the white noise levels of the full-season co-added CMB temperature maps are roughly 8, 6, and 23 uK-arcminute for the observing frequency bands centered at 95, 150, and 220 GHz, respectively. This 150 GHz noise level is comparable to that from the full four years of survey carried out by the second-generation experiment, SPTpol, which covered three times smaller of an area on the sky than SPT-3G. The performance we achieved in 2019 shows that we are on track to reach our proposed final noise levels at the end of our five-year survey (2019 through 2023). With a combination of arcminute resolution and very low noise levels, the maps of CMB temperature and polarization that will be produced by SPT-3G will allow us to improve constraints on inflationary gravitational waves (jointly with the BICEP Array experiment) and on extensions to the standard LCDM model, to find many more galaxy clusters and emissive sources, and to achieve other science goals.