Standard Pressure IUPAC defines the "standard pressure" as being 105 Pa (which amounts to 1 bar).
mcgraw-hill.com
highered.mcgraw-hill.com
Appendix 1: Property Tables and Charts (SI Units), Scroll down to Table A-5 and read the temperature value of 99.61 °C at a pressure of 100 kPa (1 bar). Obtained from McGraw-Hill's Higher Education website.