Spring has arrived in Austin, which also signals the return of potential severe weather — on the heels of an unusually cold and snowy winter.

And severe weather isn’t the only natural threat you might face in Central Texas. Here are five — in no particular order — that can hurt you or even kill you.

When is the first day of spring? See what Farmer’s Almanac predicts for Texas in 2025

No. 1: Severe weather, including floods and tornadoes

While this winter’s bitter temperatures and uncharacteristic precipitation hit Texas hard, the Lone Star State is far from finished with severe weather. In fact, 2025 has already brought flood advisories triggered by heavy rain, as well as severe storms.

Just over the weekend, the same major storm system that caused flooding in Southern California brought high winds to Texas. The strong winds combined with dry conditions to fuel several fires. Red flag warnings across the state continued into the week. The system also brought haboobs, or dust storms, into the High Plains.

More on wildfires: Bastrop County has seen five major wildfires since 2009. Experts say it’s the new normal.

The deadliest flood event in recent memory was prompted by Hurricane Harvey in August and September 2017, which directly caused 89 deaths. Another deadly flood, more local, happened during the Memorial Day weekend in 2015. Flooding across Central Texas, particularly in Hays County, southwest of Austin, left 14 people dead, including a dozen along the Blanco River.

Twisters also have taken their toll on Central Texas. The U.S. recorded at least 1,855 tornadoes in 2024, surpassing the previous record of 1,814 set in 2004. Among the states, Texas saw the most with 169 — more than doubling 2023’s total of 78.

But the deadliest tornado outbreak in Central Texas happened 27 years earlier. On May 27, 1997, the strongest of a series of tornadoes leveled neighborhoods in Jarrell, near Williamson County’s northern border, killing 27 people and injuring 12 others.

No. 2: Extreme temperatures — freezes and excessive heat

Sometimes, the weather danger isn’t from rain falling or debris flying through the air — sometimes, it’s the air itself. Austin’s fickle weather can swing temperatures from one extreme to the other.

The last two months have seen winter weather generally atypical for the Lone Star State. Austin even saw some snow, as well as plunging temperatures into the lower teens and single digits, when an arctic air system swept through Texas in February.

For some, this winter’s freezing temperatures were reminiscent of the February 2021 freeze that resulted in at least 240 deaths. The weeklong event strained the Texas power grid nearly to the point of collapse; its icy grip made roads impassable and knocked out water pipes.

As deadly as freezes can become in Austin, we’re more likely to encounter extreme heat, especially in summer, but increasingly also in spring and fall. For many local students, 2024’s first week of school was an exceptionally hot one. Heat indexes of up to 111 degrees prompted heat advisories and excessive heat warnings. Two months before, another heat wave also brought triple-digit temperatures to Central Texas.

Heat-related illnesses have been rising in Austin, a trend Mayor Kirk Watson and other officials attribute to climate change. Austin-Travis County Emergency Medical Services responded to 125 heat-related illnesses in May 2024, according to data from the organization. That’s a 150% increase from the 50 incidents the agency saw in May 2023.

Over Memorial Day weekend alone, EMS responded to 54 heat-related illnesses over three days, up from just eight in 2023.

More: Millions in danger as power outages, 106-degree heat index hit Houston one day after Beryl

No. 3: Venomous animals such as snakes

When the atmosphere isn’t presenting a threat, sometimes it’s venomous residents on the ground. Most snakes aren’t venomous, but you could come across four species that are in Central Texas:

• Western diamondback rattlesnakes, which can be identified easily by the “rattle” on their tails, are the most common rattlesnake in Texas and are most active at night.
• Coral snakes, known by their red, yellow and black stripes, have red touching yellow on their bodies. Nonvenomous snakes, such as the Texas milk snake, have red and black touching.
• Copperheads can be well-hidden in forests and have gray and brown bands.
• Cottonmouths, also known as water moccasins, have brown, dark red or tan bands, and can be aggressive while being defensive. They are not always in the water.

If you are bitten by a venomous snake, call 911. Austin-Travis County EMS recommends that you:

• Do not apply tourniquets to snakebites or try to “suck” the venom out of a snakebite.
• If possible, take a picture or get a good description of the snake, but do not try to capture it.
• Keep the injured area at or below the level of the heart.
• Apply ice or cold packs to the injured area to help reduce swelling.

No. 4: Viruses such as the flu, measles, COVID-19

A series of viruses have spread through Central Texas in the past several months, in addition to the coronavirus responsible for the COVID-19 pandemic.

There has been a sharp increase in flu-related medical visits in Travis County since the start of the year, according to Austin Public Health. The third week of January, 9.9% of emergency room visits in Central Texas were for flu. For the flu season, beginning Sept. 29, 2024, and up to March 8, 2025, 11 adults have died from influenza-associated causes. There had also been four outbreaks in schools and long-term care facilities.

More: Two people in Travis County die as high levels of flu hit Austin area; What are symptoms?

This year, Texas has also reported the first U.S. measles death in 10 years. As of March 18, the Department of State Health Services (DSHS) had identified 279 cases, 36 of which required hospitalization.

At this time, there have been no confirmed measles cases in Central Texas, as outbreaks have generally occurred in West Texas. However, it is an extremely infectious disease: 90% of people exposed to the virus who have not been vaccinated or do not have natural immunity will become infected after being exposed. The virus can live on the surfaces of a room for two hours after exposure.

The DSHS has reported possible measles exposures in Live Oak, New Braunfels, San Marcos, San Antonio and Wall.

No. 5: Water hazards such as toxin-producing algae

During the past several years, Austin’s Watershed Protection Department has been on the lookout for dihydroanatoxin-a, a potent neurotoxin that has turned up in blue-green algae growing in Lady Bird Lake and other local waterways. Since 2019, several dogs have died after ingesting water with the harmful algae, including one in July 2024.

For the past four years, the city has treated specific areas throughout the lake with lanthanum-modified bentonite, a type of clay material that binds to phosphorus in the water, making it unavailable for algae to feed on. Blue-green algae, also known as cyanobacteria, is toxic to humans and pets.

Symptoms of algae poisoning in dogs can include excessive drooling, vomiting or diarrhea, foaming at the mouth, jaundice or an enlarged liver, blood in their urine or dark urine, stumbling, loss of appetite, abdominal tenderness, progression of muscle twitches and respiratory paralysis.

Humans might experience a rash, irritation, swelling, sores, a fever, headache, eye irritation, or gastrointestinal, neurological, ear or respiratory issues.

— Former Statesman staff Roberto Villalpando contributed to this report.