Late August · Extreme heat Critical

Arizona lawn conditions

Updated

Extreme heat through Sunday midday into late week—NWS Phoenix-class highs near ~115 °F Sunday, ~108 Monday, and ~112 Tuesday under valley Extreme Heat Warning themes through Saturday evening Aug 29; NWS Tucson Extreme Heat Warning themes also run through Saturday evening Aug 29 (Tucson-class ~110/~104/~108); lower Colorado / Yuma Extreme Heat Warning themes continue through Saturday evening Aug 29 (Yuma-class highs near ~113/~111/~114); strict conservation; monsoon storm chances remain slight and patchy into late week—probe soil before skipping or adding water.

Do this week

  1. Water deep on assigned days only—check drought stage before adding minutes.
  2. Mow higher with sharp blades; avoid midday traffic on heat-stressed turf.
  3. Skip fertilizer and most herbicides until stress eases.
  4. Audit irrigation for runoff, misting, and dry spots after each cycle.

Watch for

  • Tip burn from salts or recycled water
  • Localized dry spot / hydrophobic thatch circles
  • Grubs or billbugs under irregular wilt
  • Monsoon-related fungal flare where nights stay humid
Regional notes & context

Why this week

Peak summer in Arizona is about keeping crowns alive under high evaporative demand—not chasing emerald color. NWS heat-dome patterns still favor widespread near-/above-100 °F from Texas into the Southwest through Sunday midday into late week (Dallas-class highs near ~107 Sunday / ~107 Monday / ~106 Tuesday with Extreme Heat Warning themes active through Sunday evening Aug 23 for many North Texas counties—South Texas Corpus Christi-class Heat Advisories remain active through Sunday evening Aug 23 while Brownsville-class Heat Advisories are expired this midday; Austin-class Extreme Heat Warning themes run through Sunday evening Aug 23 before Heat Advisories continue through Wednesday evening Aug 26 with highs near ~105/~104/~105; San Antonio-class Heat Advisories continue through Wednesday evening Aug 26 with highs near ~104/~102/~103; Houston-class Heat Advisories continue through Monday evening Aug 24 with highs near ~101/~100/~103; El Paso-class Heat Advisories remain expired this midday with highs near ~101 Sunday / ~104 Monday / ~102 Tuesday; Phoenix-class highs sit near ~115 Sunday / ~108 Monday / ~112 Tuesday under valley Extreme Heat Warning themes through Saturday evening Aug 29; Tucson-class Extreme Heat Warning themes also run through Saturday evening Aug 29 with highs near ~110/~104/~108; lower Colorado / Yuma / Imperial / Chuckwalla Extreme Heat Warning themes continue through Saturday evening Aug 29 with Yuma-class highs near ~113/~111/~114; Coachella / Palm Springs-class highs near ~116 Sunday / ~111 Monday / ~111 Tuesday under Coachella / San Diego County Deserts Extreme Heat Warnings through Friday evening Aug 28; Las Vegas / Northwest Desert-class ~110 Sunday / ~107 Monday / ~106 Tuesday under Extreme Heat Warning themes through Sunday evening Aug 23 for Lake Mead / Las Vegas Valley / Northwest Desert zones; Salt Lake-class ~96 Sunday / ~96 Monday / ~95 Tuesday with metro Heat Advisories expired; Fresno / Central Valley-class ~104 Sunday / ~106 Monday / ~106 Tuesday with Extreme Heat Warning themes expired but Inland Empire / LA-basin Heat Advisories active through Tuesday morning Aug 25 and Extreme Heat Watches through Friday evening Aug 28; Albuquerque-class ~97 Sunday / ~98 Monday / ~98 Tuesday after metro Heat Advisories expired); NHC Atlantic Tropical Weather Outlook (800 AM EDT Sun Aug 23): Northeastern Atlantic non-tropical low west of Portugal has formation chances low ~10% in 48 hours and low ~10% through 7 days (further development not expected after tonight); Central Subtropical Atlantic disturbance AL95 several hundred miles southeast of Bermuda has low ~20% in 48 hours and low ~30% through 7 days (slow development possible while drifting west/northwest then accelerating north early this week); Eastern Tropical Atlantic wave expected to move off Africa Monday has near 0% in 48 hours and medium ~50% through 7 days (a tropical depression could form by mid-to-late week while moving generally west at 15–20 mph); SE Texas stays hot with Houston-class Heat Advisories through Monday evening, expanding Plains drought, and watering restrictions make calendar watering risky. Without a reliable leach rain, soluble salts and specific ions concentrate in the top inch.

Seasonal notes

  • Flush salts only when your water rules allow and turf can use the water.
  • Coastal vs inland microclimates differ sharply—follow your district first.
  • Warm-season species usually handle heat better than leftover cool-season pockets.

Last updated

Content refreshed August 23, 2026 (Sunday midday) for Arizona. Educational orientation only—not a site-specific diagnosis.