Markets expect the Fed to keep rates on hold, but have priced about a 40% chance of another hike by year's end.
Canada's bigger-than-expected bounce in consumer prices, driven by surging gasoline costs, might provide handy evidence for the Fed to err on the restrictive side of rates settings.
Markets have roughly doubled the likely risk of a hike in Canada to about 40% after annual headline inflation jumped to 4% in August from 3.3% a month earlier.
Higher energy prices could also drive a surprise in British CPI at 0600 GMT, where economists see the year-on-year headline figure rising to 7% in August from 6.8% in July.
Sterling has found support from the risk of a hot reading, with a 32% rise in Brent crude futures over the past three months pointing to upside risks and more chance the Bank of England hikes rates beyond an expected rise on Thursday.