Arizona weather forecast: First 100 degree day for Phoenix in 2026
Evening Weather Forecast - 3/18/26
The heat is here! Phoenix hit the 100s for the first time this year, and it's only going up. FOX 10's Erica Horvatin has the details on how long we can expect the extreme heat warning.
PHOENIX - Our long stretch of record weather begins today.
Today:
Wednesday was a record warm day for all of Arizona. The Phoenix-area saw its earliest 100 degree day on record. The forecast high hits 101 today in Phoenix.
This will break a variety of records: the earliest 100+ degree day on record, the hottest March temperature on record, and the hottest temperature for the date. This will also begin a 5-day-long stretch of triple digit days and a 7-day-long stretch of record temperatures in Phoenix.
Tonight, it will fall to 69 degrees in the Valley, which will be a record warm morning low.
Tomorrow & This Weekend:
Many areas in the high country will see their earliest 80 degree day on Thursday, like Flagstaff, and their earliest 90 degree days, like Prescott, Winslow and Sedona.
Thursday will heat to 104 degrees in Phoenix.
The heat wave will peak by Friday, but temperatures will stay record warm through next week. Friday will be even hotter, with a high of 106, and Saturday will be back at 104 degrees. Skies will be sunny through the weekend.
Extreme heat warnings will be in effect from Thursday through Sunday. During this time, some Phoenix hiking trails will be closed from 8 a.m. to 5 p.m., but keep in mind that temperatures will remain at their highest until after the sun sets at 6:38 p.m.
Looking Ahead:
There's very little relief in the long run. The forecast high returns to 99 on Monday and Tuesday, and 98 by next Wednesday. It remains dry through the entire 10-day forecast.
You can always check the latest weather conditions by visiting the FOX 10 Phoenix weather page, or download the Free FOX 10 Weather app, which is available on Apple iOS and Android.
Scroll down this page for satellite and radar, day planner, records, current temperatures, 10-day forecast, forecast highs, and recent rainfall totals, plus live video feeds.
The following heat safety information was provided by the Scottsdale Fire Department.
What are Heat Emergencies?
Heat Cramps: Profuse sweating, fatigue, extreme thirst, muscle cramps
Heat Exhaustion: Headache, dizziness, weakness, nausea/vomit, Cool/moist skin
Heat Stroke: Elevated temp. +103degrees, confusion/irrational behavior, dry/hot skin, rapid shallow breathing, rapid weak pulse (shock), seizures, unconscious
What to do
- Get person into shade or cool location
- Cool person with cool, wet cloths (neck, groin, armpits, head) and fan body
- Sip cool water if person is alert
- For muscle cramps, massage muscles gently, but firmly until relaxed
- *If symptoms worsen, call 911
What not to do
- Do not give anything by mouth if person is vomiting, unable to swallow or unconscious
- Do not underestimate the seriousness of a heat emergency
- Prevention/Preparation for hike/exercise in heat
Know your limitations
- Hydrate (begins day prior to hike/exercise, hour before hike, during and after)
- Wear proper clothing, lightweight and light color, protect head, proper shoes
- Always carry a cell phone and best to hike with company
- Always tell someone where you are hiking and when to plan to return
Preventing heat exhaustion/heat stroke
The Arizona Department of Health Services stated the following precautions can be taken to prevent heat exhaustion or heat stroke:
- Stay in air-conditioned buildings
- Find a cooling center/hydration station
- Limit outdoor activity during the hottest part of the day (mid-day)
- Check on at-risk friends, family, and neighbors at least twice a day
- Drink water before, during, and after working or exercising outside
- Check the UV Index
- Check the heat risk map
Road Conditions
- Call 511 anywhere in Arizona or 1-888-411-ROAD (7623)
- az511.com
The Source: Information for this story was gathered from the FOX 10 Weather Experts.