Publication Date June 15, 2016 | Weather Underground

U.S. Heat Builds: Parts of Southwest May Approach All-Time June Highs

United States
Average date of peak summertime temperature varies from late June near El Paso, TX, to late August along parts of the TX and LA Gulf Coast. Sunlight is most intense near the summer solstice (usually June 20 or 21), which heats up dry areas quickly, but the peak summer heat often takes a few weeks to build in relatively moist areas, especially the south-central states. Image: NOAA / NWS
Average date of peak summertime temperature varies from late June near El Paso, TX, to late August along parts of the TX and LA Gulf Coast. Sunlight is most intense near the summer solstice (usually June 20 or 21), which heats up dry areas quickly, but the peak summer heat often takes a few weeks to build in relatively moist areas, especially the south-central states. Image: NOAA / NWS

Late June is typically the hottest time of the year in southeast New Mexico, southern New Mexico, and far west Texas. It usually takes till July for the deserts of southwest AZ and southern CA to hit their peak of summer heat, so the upcoming heat wave is an early one there. An excessive heat watch is already in effect across parts of the far Southwest, where temperatures are expected to peak above the century mark on Sunday and/or Monday in such cities as