The Delta breeze on Monday is expected to continue influencing temperatures in Northern California to keep highs below average. Monday looks great for getting outdoors. The Delta breeze is helping to lower temperatures to start the work week. Valley highs are likely to be in the upper 80s to low 90s, while the Foothills could stay in the mid to upper 80s. The Sierra will see some afternoon clouds build with storm chances down the east slope, with highs in the low-to-mid 70s.