Southwest March Heat Wave Now Sends 112°F to Yuma Desert and 90°F Temperatures Into Nebraska
An unprecedented March heat wave is scorching the Southwest, shattering daily and monthly records — including a 112°F reading in the Yuma Desert Friday (with two Southern California sites also reaching 112°F), earlier 110°F reports near Martinez Lake and a 108°F tie at North Shore — while Phoenix, Las Vegas and other cities have logged their earliest or highest March highs and more than 41 million people remain under heat alerts. The same heat dome has pushed 90°F readings into Nebraska and triggered red‑flag wildfire warnings, and researchers say the event would have been virtually impossible without human‑caused climate change amid a rising trend in extreme heat and costly weather disasters.
📌 Key Facts
- A historic March heat wave escalated through the week: North Shore, California, hit 108°F (tying the U.S. March record first set in Rio Grande City, Texas, in 1954); nearby desert spots (including Cathedral City and Thermal) reached 108°F and were forecast to climb, with Martinez Lake, Arizona, recording 110°F and the Yuma Desert registering 112°F on Friday — the highest March temperature yet recorded in the United States. Two Southern California locations also reached 112°F on Friday.
- Major cities across the Southwest set or tied March records: Phoenix recorded its earliest triple‑digit reading (101°F on March 18) then rose to 105°F as the week continued; Las Vegas posted new March highs (including a 99°F reading); downtown Los Angeles hit 94°F (beating a 1997 daily record) and Palm Springs reached 104°F (tying its March record).
- The heat dome produced temperatures roughly 20–30°F above normal for many locations, pushing triple‑digit or near‑triple‑digit readings into desert areas and driving temperatures above 90°F as far north as Nebraska, followed by sharp drops into the 50s–60s and prompting red‑flag wildfire warnings.
- More than 41 million people were under heat alerts through the weekend, and the National Weather Service (NWS) described this as one of the most significant March heat waves in recorded history, with many daily records broken in a short span.
- On‑the‑ground impacts included Phoenix hiking‑trail closures because of heat‑illness risk and a 63‑year‑old hiker (Win Marsh) cutting short a planned 170‑mile Arizona Trail trek due to extreme heat, disappearing shade and drying water sources.
- Climate attribution and context: the World Weather Attribution group found the March Southwest heat wave would have been virtually impossible without human‑caused climate change; NOAA and analyses show the U.S. is now breaking many more heat records than in past decades, the area hit by extreme weather has roughly doubled compared with 20 years ago, and the number and inflation‑adjusted cost of U.S. billion‑dollar weather disasters have risen substantially.
- Experts said the current extremes are pushing beyond historical planning assumptions and are “outside the historical playbook,” and they warn that April, May and June are likely to be hotter than normal across almost the entire United States.
- Forecasters warned the heat was persisting into the weekend (e.g., NWS forecasts calling for around 100°F in Tucson and about 105°F in parts of the Yuma Desert), with additional cities projected to see their earliest 100°F days on record if the pattern continued.
📊 Relevant Data
In Arizona's Maricopa County in 2023, White individuals comprised about 80% of the population but accounted for only 60% of heat-related death victims, indicating overrepresentation of racial minorities such as non-White Latinos, Blacks, and American Indians who make up about 20% of the population but 40% of victims.
Arizona's Heat-Related Death White Paper: Full Report — MAP AZ Dashboard
Between 2018 and 2021 in the US, American Indian and Alaska Native (AIAN) people had the highest rate of heat-related deaths among racial and ethnic groups, followed by Black people with a higher rate than White people, while Hispanic people's rate was similar to White people's and Asian people's was lower; noncitizens were more likely to die from heat exposure than citizens.
Continued Rises in Extreme Heat and Implications for Health Disparities — KFF
In a 2024 study using data from 1993-2005 with projections to 2022, Black non-Hispanic individuals aged 65+ had a heat-related mortality increase of 3.8 per 1,000 on hot days (>95th percentile temperatures) compared to 1.8 per 1,000 for White non-Hispanic individuals, with counterfactual excess death rates in 2022 at 26.6 per 100,000 for Black non-Hispanic versus 15.4 per 100,000 for White non-Hispanic.
Racial disparities in deaths related to extreme temperatures in the United States — One Earth (Cell Press)
In the US, Hispanic, non-Hispanic Black, American Indian, and Asian persons are 16.5%, 34.9%, 49.1%, and 3.6% more likely, respectively, to live in areas with high heatwave frequency compared to the national average, based on data from 1981-2020.
Racial/ethnic disparities in the distribution of heatwave frequency and intensity across the USA — Nature Scientific Reports
📰 Source Timeline (6)
Follow how coverage of this story developed over time
- Reports that Yuma Desert, Arizona, reached 112°F on Friday, described as a record for the highest March temperature in the United States.
- National Weather Service forecast for March 21 calling for 100°F in Tucson and 105°F in the Yuma Desert, showing the heat wave persisting.
- Confirmation that two locations in Southern California also reached 112°F on Friday.
- Evidence that the same heat dome is now pushing temperatures above 90°F into Nebraska, followed by a sharp drop into the 50s–60s and prompting red-flag wildfire warnings.
- On-the-ground account from hiker Win Marsh, 63, who cut short a 170-mile Arizona Trail trek due to extreme heat, disappearing shade and drying water sources.
- Experts cited saying April, May and June are likely to be hotter than normal across almost the entire United States.
- World Weather Attribution group finds the March Southwest heat wave would have been virtually impossible without human-caused climate change.
- AP analysis of NOAA data shows the U.S. is now breaking 77% more hot weather records than in the 1970s and 19% more than in the 2010s.
- NOAA’s Climate Extremes Index shows the area of the U.S. hit by extreme weather in the past five years has doubled compared with 20 years ago.
- NOAA and Climate Central data indicate the number and inflation-adjusted average cost of U.S. billion‑dollar weather disasters in the last couple of years is twice as high as a decade ago and nearly four times higher than 30 years ago.
- Experts, including Climate Central’s Bernadette Woods Placky and former FEMA Administrator Craig Fugate, characterize current extremes as pushing beyond historical planning assumptions and "outside the historical playbook."
- National Weather Service reports 110°F (43.3°C) recorded near Martinez Lake, Arizona, in the Yuma Desert, now the highest March temperature ever recorded in the United States.
- The previous 108°F March record, set in Rio Grande City, Texas in 1954 and tied Wednesday at North Shore, California, was surpassed on Thursday.
- Additional California desert locations, including Cathedral City and Thermal, hit 108°F Thursday, with Thermal forecast to reach 110°F on Friday.
- Phoenix reached 105°F Thursday, breaking the 102°F March record set the day before and marking its earliest triple‑digit day on record; Las Vegas hit 95°F, also a March record.
- Phoenix hiking trails were closed Thursday because of heat‑illness risk as temperatures across the Southwest stayed 20–30°F above normal for March.
- Confirms the record-tying 108°F reading occurred in North Shore, California, explicitly naming the community.
- Notes that more than 41 million people remain under heat alerts through Sunday, according to CBS News meteorologist Nikki Nolan.
- Provides additional city-level records: Las Vegas hit 99°F (breaking its prior March record of 93°F), downtown Los Angeles reached 94°F (beating a 1997 daily record of 87°F), and Palm Springs hit 104°F (tying its March record from 1966).
- Reports Phoenix’s earliest-ever triple-digit reading in March at 101°F on Wednesday, breaking the previous March 26, 1988 record and marking only the second March 100°F day on record there.
- Quotes NWS meteorologist Bryan Lewis calling this "one of the most significant March heat waves in recorded history" and emphasizing how many daily records have already been broken.
- Projects that the aptly named Thermal, California, was forecast to reach 110°F on Friday and that many other cities may see their earliest 100°F day on record, with temperatures staying 20–30°F above normal into the weekend.
- North Shore, California, hit 108°F on Wednesday, March 18, 2026, tying the highest March temperature ever recorded in the United States, previously set in Rio Grande City, Texas, in 1954.
- The nearby community of Thermal, California, is forecast to reach 110°F on Friday, which would break the existing March record if realized.
- Phoenix reached 101°F on March 18, its earliest 100-degree day on record and only the second time it has hit triple digits in March (the previous was 100°F on March 26, 1988).
- Las Vegas reached 99°F, setting a new all‑time March record and breaking its prior March high of 93°F from 2022.
- Downtown Los Angeles hit 94°F, surpassing its previous daily record of 87°F set in 1997, while Palm Springs reached 104°F, tying its hottest March day on record from 1966.
- NWS meteorologist Bryan Lewis said this is one of the most significant March heat waves in recorded history, with many locations running 20–30°F above normal and “so many records” being broken in a short span.