Expect more record-breaking temperatures this weekend as the historic March heat wave begins to dissipate. The National Weather Service predicts temperatures will remain in the low 90s, with the average high for late March in the valley expected to be in the mid 70s. Despite this, temperatures are expected to return to the lower 70s after a period of high temperatures. By the end of the month, the valley is likely to have recorded at least 10 90-degree days, an all-time record.