The Texas Rangers have received a special exemption during the hot Texas summers to play Sunday games in the evening without interfering with the usual ESPN Sunday night telecast. Normally, the weather isn't an issue, but Sunday night Mother Nature intervened very loudly in the top of the fourth inning.
The Twins and Rangers were in a 44 minute weather delay with the game still scoreless as the result of a large nearby lightning strike. As the video here shows, it quickly sent the players and umpires scrambling for cover:
Rangers' catcher Mike Napoli was especially startled by the thunderclap, as he almost immediately bolted for the Texas dugout and was off the field almost before the sound of thunder faded into the distance.
One benefit of the unexpected shower was that the temperature dropped significantly from a first pitch reading of 96 degrees. Temperatures dropped to a much more comfortable 80 degrees.