FLAGSTAFF, Ariz. (AP) — Weather forecasters said the temperatures will gradually warm up this week in Arizona and should eliminate the possibility of more record low temperatures any time soon.

The last time Flagstaff had temperatures colder than they've been over the past five days was in late December 1990. This time around, the high was about 25 degrees over five days, and the low was negative 9 degrees.

The Flagstaff Fire Department expects more emergency calls this week as broken water pipes begin to thaw.

The much lower-lying Phoenix area is under a freeze warning until Wednesday morning, with a hard freeze warning in effect for Kingman, Tucson and other parts of southeastern Arizona.

Lettuce growers in southwestern Arizona are facing shortages because of persistent cold weather that has reduced the quality of the crops.