The Australian dollar is the most direct read-through. A print at or above forecast would strengthen the case for further tightening and could support the currency and short-dated yields. A softer result, particularly in trimmed mean, would invite doubts about how far the central bank needs to go. Because the RBA has already moved, the data now shapes expectations for the next decision rather than the last one. For oil, the relevance is indirect, through the Australian dollar and broader risk sentiment.---Australia's August CPI arrives one day after the RBA hiked, with headline inflation forecast to accelerate to 4.0% while the underlying trimmed mean gauge is expected to hold at 3.6%.Summary:Australia publishes August CPI at 01:30 GMT on Wednesday, September 30 (21:30 US Eastern on Tuesday, September 29).The release follows the RBA's 25bp cash rate increase on Tuesday, September 29.Headline CPI is forecast at 4.0% y/y versus a prior of 3.5%.Monthly CPI is forecast at 0.4% versus a prior of 1.0%.Trimmed mean is forecast at 3.6% y/y, unchanged from the prior, and 0.3% m/m versus 0.5%.Australia releases its August consumer price data today, Wednesday, September 30, at 01:30 GMT, which is 21:30 US Eastern time on Tuesday, September 29. The report arrives one day after the Reserve Bank of Australia raised its cash rate by 25 basis points, so traders will be looking to the numbers for guidance on what the central bank may do next.Forecasts point to a faster headline rate. Annual CPI is expected to rise to 4.0%, up from 3.5% in the prior reading. On a monthly basis, prices are forecast to increase 0.4%, a slower pace than the 1.0% recorded previously. That combination suggests the annual figure is being driven at least in part by comparisons with earlier months rather than by a fresh surge in prices, although the forecasts alone cannot confirm that.The trimmed mean measure is the one policymakers tend to watch most closely for underlying pressure, because it strips out the most extreme price movements. Here the forecasts are steadier. The annual rate is expected to hold at 3.6%, unchanged from the prior reading, while the monthly rate is forecast at 0.3%, compared with 0.5% before. A result in line with those forecasts would show underlying inflation holding at an elevated level rather than accelerating.The outcome matters because the RBA has just tightened. A reading at or above forecast, especially in trimmed mean, would lend support to the argument that further tightening could be needed. A softer outcome would give the market reason to question that path. The distinction between the headline and underlying figures is likely to shape the reaction, since a headline beat alongside a trimmed mean miss would send mixed signals.Investors will next look to the RBA's communication and subsequent data releases to judge whether the latest increase is the start of a sequence or a single adjustment. This article was written by Eamonn Sheridan at investinglive.com.