NEW : Wednesday will be either hot or wet for 19 regions of country . NEW : Extreme heat will continue in The Pacific Northwest , but rain will drench Southeast . Southwest will get a break from blazing temperatures . Nevada 's massive wildfire could get rain , but also wind gusts and lightning .
NEW : Fourth of July will be either hot or wet for two regions of country . NEW : Extreme heat will continue in Southwest , but rain will drench Southeast . The Pacific Northwest will get a break from blazing temperatures . Arizona 's massive wildfire could get rain , but also wind gusts and lightning .