Trumbo entered Wednesday with just three extra-base hits in August, all homers. He was hitting .216 in 18 games this month.
"I've been hitting the ball hard, but they're singles, hadn't had any extra-base hits in a while, but I knew it was a matter of time," Trumbo said. "Hopefully this is a turning point and a I'll have a nice month and a half."
Trumbo made some minor adjustments to his swing recently.
"I can't pinpoint one thing, but this just feels more like my swing," he said. "My swing had been over-aggressive. I tried to tone it down a bit. My biggest thing is when I get a pitch to hit I don't want to miss it. It doesn't mean I'm always going to get a hit, but I need to be in a position to attack it."
Trumbo attacked a 3-2 offering from Aaron Cook in the fifth inning on Tuesday, sending it over the Green Monster and out of Fenway Park for his 30th homer this season. The blast was estimated at 440 feet.
"That's just Trumbo -- any time he barrels up a ball that's how far it goes," Angels catcher Chris Iannetta said.
Trumbo is the first Angels player with at least 30 home runs in a season since Kendrys Morales had 34 in 2009. He's also homered in each of his three games at Fenway entering Wednesday.