Recent showers temporarily relieved drought conditions in parts of the southwestern United States, but dry weather will persist through the summer.

Forecasters said Monday a months-long drought is considered "extreme" from southern California to central Kansas. Conditions are even worse in the Four Corners region and the Oklahoma and Texas panhandles.

The drought has contributed to numerous wildfires. Forecasters say it will last at least through July, with some improvement east of a line from Albuquerque to Denver.

The scientists said the desert-like air is responsible for some anomalies. At Alva, Oklahoma, the temperature last Tuesday climbed from 33 degrees to 101 in less than a day.

Also, Oklahoma hasn't had a tornado this year and storms aren't expected. The state hasn't had an April without at least one tornado.