Higher-than-average temperatures this weekend will be followed by a high pressure system that is expected to move over the region and bring monsoonal conditions mid-week.
Monsoonal moisture was expected to increase on Wednesday, leading to a slight chance of afternoon thunderstorms over the mountains, a condition that will continue through Friday, the NWS said.
Warming was forecast west of the mountains later in the week.
High temperatures Sunday were 113 degrees in Palm Springs, 112 degrees in Thermal, 99 degrees in Hemet, 98 degrees in Riverside and 92 degrees in Temecula.
Similarly hot temperatures are expected throughout the week.
A list of cooling centers in Riverside County can be found at capriverside.org/Portals/2/PDF/Cool/May2022/2022@CoolCenterDirectory.pdf.