The monthly Recruitment and Employment Confederation (REC) and KPMG Report on Jobs shows that temporary staff demand was at its highest rate since July 1998.
The report also shows the number of permanent vacancies continued to rise in August, but the number was not as high as July.Demand for staff in the IT/computing sector in August was the third highest in the nine sectors measured, with IT/computing behind engineering and "executives/professionals". In the temp sector IT/computing was fifth.
Sought-after skills in short supply in IT/computing were business analysts, C++, developers, digital marketers, e-commerce, HTML5, Java and PHP.
The total number of staff placed in permanent roles continued to increase at a "marked pace in August", said REC, although growth eased from July's 40-month high.
Underpinning the rise was the fastest increase in available permanent vacancies since June 2007.
The rate of inflation of permanent staff salaries overall accelerated in August, reaching its highest level in five-and-a-half years. Temp pay rates also continued to rise, although the pace of inflation was slightly slower than the five-and-a-half year high seen in July.
REC chief executive Kevin Green said: "August was an extraordinary month for the UK jobs market, with temp placements growth hitting a 15-year high.
"There is more good news for all workers with pay rates for temps rising for the seventh consecutive month and starting salaries for permanent staff increasing at the highest rate in five-and-a-half years."