NWS Forecast Office Phoenix, AZ

Above normal temperatures will continue this week with the warmest readings resulting in areas of moderate to locally major HeatRisk. Afternoon highs will be around 10 degrees above normal and near daily records across the western deserts.

High pressure over the region will continue to result in dry conditions along with unseasonably hot conditions through the end of the week as lower deserts highs exceed the triple digits. A more unsettled pattern may develop by this weekend as an area of low pressure amplifying over the west coast helps to draw in tropical moisture, bringing increasing rain chances and much cooler temperatures. At this time, there is very high uncertainty with the rain forecast, especially with rainfall amounts. Please stay tuned for forecast updates through the rest of the week as details become more clear!

October 5th is the average last 100 degree day of the year for Phoenix. The latest 100 degree day on record occurred on Oct 27th, 2016, so it is climatologically possible to see 100 degree days last through late October.

Monsoon season temperatures finished above normal at all three climate sites, with the overnight lows being the most above normal for all three climate sites. Rainfall totals were above normal at Phoenix, and below normal at Yuma and El Centro.