The warning applies on Friday afternoon and during the evening. It affects large parts of the inland and southeastern Götaland mainland and inland Svealand.
It's extremely difficult to say exactly where the showers will fall, says SMHI's meteorologist Hilda Westberg.
SMHI also warns of high temperatures in parts of northern Sweden. On Friday, an orange heat warning has been issued for parts of northeastern Norrland. For parts of eastern Västerbotten County and parts of northern Västernorrland County, a yellow heat warning has been issued. Temperatures of 30 degrees are expected, locally up to 33 degrees.
Going into the Saturday period, a cold front with slightly cooler air and also some precipitation will sweep over Norrland, says Hilda Westberg.
Corrected: In an earlier version, incorrect level of warning for heavy rain was stated.