By The Katy News Staff
Published July 25, 2026
KATY, Texas — Residents across the Katy area should prepare for several days of dangerous summer heat, with the heat index forecast to reach approximately 107 degrees Sunday before actual temperatures climb into the triple digits next week.
The National Weather Service forecast for Katy calls for a high near 97 degrees Sunday, July 26. High humidity could make conditions feel as hot as 107 degrees during the afternoon.
The temperature is expected to reach approximately 98 degrees Monday, 100 Tuesday and 101 Wednesday. Forecast highs could remain near 101 through Thursday, extending the period of potentially hazardous heat.
Although an isolated shower or thunderstorm could briefly develop Sunday afternoon, the chance of rain is only about 20%. Any isolated rainfall is unlikely to provide widespread relief from the heat.
Katy Forecast Shows Several Days of Increasing Heat
The latest Katy forecast includes:
- Sunday: High near 97 degrees with a heat index reaching approximately 107. A 20% chance of a late-afternoon shower or thunderstorm.
- Monday: Sunny and hot with a high near 98.
- Tuesday: Sunny with an expected high near 100.
- Wednesday: Sunny and hot with a high near 101.
- Thursday: Mostly sunny with a high near 101.
Nighttime temperatures are expected to remain in the middle to upper 70s before approaching 80 degrees later in the week. Warm nights can increase heat stress because people without reliable air conditioning receive less relief after sunset.
Forecast temperatures and advisories can change. Residents should monitor the National Weather Service Houston-Galveston office for updated information.
Why the Heat Index Matters
The heat index estimates how hot the air feels when humidity is combined with the actual temperature.
When moisture levels are high, sweat does not evaporate from the skin as efficiently. That reduces the body’s ability to cool itself and can make a temperature in the upper 90s feel considerably hotter.
A heat index above 100 degrees can increase the risk of heat exhaustion and heat stroke, particularly during prolonged outdoor activity.
Children, older adults, outdoor workers, athletes and people with certain medical conditions may face an elevated risk. Residents without dependable air conditioning can also become vulnerable as the heat continues for several consecutive days.
Outdoor Workers and Athletes Should Take Extra Precautions
Construction crews, landscapers, delivery drivers, security technicians and others who work outside should take frequent breaks in shaded or air-conditioned areas.
Whenever possible, strenuous work should be scheduled during the early morning. Workers should drink water regularly instead of waiting until they feel thirsty.
Employers and supervisors should watch for changes in a worker’s coordination, behavior or ability to communicate. Confusion can be a sign of a medical emergency rather than ordinary fatigue.
Youth sports teams, summer camps and families planning outdoor activities should also reconsider afternoon schedules. Coaches should provide frequent water breaks and allow participants to stop if they begin feeling unwell.
Artificial-turf fields, playground equipment and paved surfaces can become considerably hotter than the surrounding air.
Know the Signs of Heat Exhaustion
According to the Centers for Disease Control and Prevention, symptoms of heat exhaustion can include:
Dangerous heat is expected across the Katy area as temperatures approach and exceed 100 degrees.
- Heavy sweating
- Headache
- Nausea
- Dizziness
- Weakness
- Irritability
- Thirst
- Elevated body temperature
- Reduced urine output
A person experiencing possible heat exhaustion should be moved into a cooler area, given water if alert and able to drink, and cooled with wet cloths or circulating air.
Symptoms that worsen or fail to improve require medical attention.
Heat Stroke Is a Medical Emergency
Heat stroke can occur when the body loses its ability to regulate its temperature.
Warning signs may include confusion, slurred speech, loss of consciousness, seizures or extremely hot skin. A person experiencing suspected heat stroke may no longer be sweating, although sweating can still occur in some cases.
Call 911 immediately if heat stroke is suspected. Move the person to a cooler location and begin cooling with cold water, wet towels or ice packs while waiting for emergency responders. Do not force an unconscious or confused person to drink.
Never Leave Children or Pets in Vehicles
A parked vehicle can become dangerously hot within minutes, even when a window is partially open.
Parents and caregivers should check the entire vehicle every time they park. Placing a needed item—such as a phone, work badge or bag—in the back seat can serve as an additional reminder.
Pets should never be left inside a parked vehicle. Owners should also test pavement before walking a dog. If the surface is too hot to hold a hand against comfortably, it may burn an animal’s paws.
Walks should be moved to the early morning or later evening when temperatures are lower.
How Katy Families Can Prepare
Residents can reduce their risk by taking several precautions:
- Drink water regularly throughout the day.
- Limit strenuous outdoor activity during the afternoon.
- Wear lightweight, light-colored and loose-fitting clothing.
- Use sunscreen and seek shade whenever possible.
- Check on older relatives, neighbors and people living alone.
- Make sure outdoor pets have shade and fresh water.
- Confirm that air-conditioning systems are working properly.
- Never leave a child, adult or animal unattended in a vehicle.
Families should also have a plan for reaching an air-conditioned location if their home loses power or their cooling system stops working.
Heat Could Continue Through the End of the Week
The hotter and drier pattern is expected to remain over Southeast Texas through much of the coming week. A change in the weather pattern could eventually bring additional rain chances, but the timing and cooling effect remain uncertain.
Until then, the greatest concern will be the combination of high afternoon temperatures, elevated humidity and limited overnight cooling.
The Katy News will continue monitoring National Weather Service forecasts and any heat advisories issued for Harris, Fort Bend or Waller counties.
