The heat is on in Tucson with the first 90-degree day coming Thursday, weeks ahead of normal:

• Forecast high today: 93

Record: 93 in 1910

• Thursday record high: 92

Old record: 87 in 2007

• Wednesday record high: 89

Old record: 88 in 1989

• Average first 90-degree day in Tucson: April 10

• Weekend forecast:

Slightly cooler, highs:

89 on Saturday

86 on Sunday