For the first time this season the Rogers Centre roof will be open this weekend — weather permitting — as the Blue Jays take on the Oakland Athletics.

Final testing of the 25-year-old stadium’s retractable roof was completed Thursday afternoon and, in theory, it could be open for Friday night’s game against the A’s. But with thunderstorms in the forecast, Saturday is the more likely “Dome Opener.”

Many fans were disappointed earlier this month when the roof remained closed despite a clear-skied, sunny afternoon with temperatures above 20C.

But given the length and depth of this year’s winter and the colder-than-normal spring temperatures the requisite testing was pushed back, said Stephen Brooks, the Jays senior vice-president of business operations.

The dome is sealed through the winter and roof testing can’t begin until all snow and ice has melted. Temperatures below 10C also put the opening and closing of the roof at risk, so testing requires several days of temperatures consistently north of that.

Last season, the first open-dome game was May 2; in 2012, it was April 19, the second-earliest date ever (April 16 is the earliest). Three years ago it was May 7. But Brooks said that while this year’s first open-dome game is later than it has been in recent years, it is around the average for the building’s lifespan.

The Jays’ scheduled starter for Saturday, R.A. Dickey, would be grateful for lousy weather. The knuckleballer prefers pitching in a closed dome, where his winning percentage was twice as high last season, compared to an open-air field, and he allowed one-and-a-half fewer runs on average.