Severe Weather Guide

lightning storm

Severe weather is possible in Johnson County throughout the year. This hazardous weather can put people’s safety at risk and causing damage to property. Johnson County may experience severe weather at any time of the year, including:

  • Tornadoes
  • Thunderstorms
  • Lightning
  • Strong winds
  • Hail
  • Floods

As severe weather approaches, follow updates from the National Weather Service, trusted local news outlets and public safety officials. Notify JoCo is also a crucial source of information, a free mass notification system sending text alerts to Johnson County residents in cases of emergencies – including severe weather events.

Severe weather is possible in all four seasons in Johnson County, but the spring sees the highest possibility of tornadoes in the county. In addition to tornadoes, these severe storms can often bring damaging straightline winds, large hail and flash flooding.

In Johnson County, the outdoor warning sirens are owned and maintained by the local jurisdictions. However, Johnson County Emergency Management has the primary responsibility of activating those sirens. The sirens are only activated for a tornado warning. If you hear these sirens, take shelter immediately and look for additional information. These sirens are tested on the first Wednesday of each month at 11 a.m.

Storm cloud with rain falling down

Severe Weather Preparedness Week

Severe Weather Awareness Week is a good time to prepare for all sorts of severe weather events, from thunderstorms to tornadoes to floods. Johnson County experiences these types of severe weather and more, and it’s important to take precautions to stay safe.

Learn more about each day of Severe Weather Awareness Week, taking place March 4-8, 2024, and follow these tips from the National Weather Service to prepare yourself and your family for severe weather events.


Yellow folder with an emergency plan inside it

Monday – Preparedness

Staying prepared is key to staying safe when severe weather strikes. Work with your family to create an emergency plan, practicing drills at home and knowing your places of shelter.

Be sure to also organize an emergency kit full of medical supplies, and stay informed on the weather wherever you get your news. If you haven’t, sign up for emergency alerts from Notify JoCo.

Johnson County will be conducting the annual county-wide test of Notify JoCo on Tuesday, March 5 at 10 a.m.

Tornado touching the ground next to a two-lane road

Tuesday – Tornado Safety

Tornadoes are prevalent throughout the Midwest, especially in Kansas, and they can bring wind speeds of more than 200 miles per hour. Pay attention to tornado watches and tornado warnings, and know where to take shelter – whether it’s a basement or windowless interior room.

This year’s tornado drill will occur on Wednesday, March 6 at 11 a.m. We encourage you to promote this drill as an opportunity for schools, businesses and households to practice sheltering as if it were a real tornado.

Lightning striking the ground during the nighttime

Wednesday – Lightning Safety

Thunderstorms can create a variety of severe weather, one of the most dangerous being lightning. Remember, when thunder roars, go indoors – a sign of thunder means lightning isn’t too far behind.

Avoid using electronic devices connected to outlets during a thunderstorm, and watch for fallen power lines and trees.

Hail on the ground alongside a road as a car drives by

Thursday – Hail/Wind Safety

Hail and wind are highly damaging weather events, also a byproduct of severe thunderstorms. Softball-sized hail can damage cars and roofs, while high-speed winds – often exceeding 100 miles per hour – can down trees and blow large items into the air.

Stay indoors and away from windows to stay safe from these types of severe weather.

Flooded neighborhood, high waters and houses in the background

Friday – Flood Safety

Floods are the most common natural disaster in the United States, and can be extremely costly as well. Floods often develop quickly, so paying attention to flood warnings is vital.

Turn around, don’t drown – a car can quickly get swept away if you make the mistake of driving into floodwaters. Move to higher ground or evacuate if you have to.

Local Media


The local news media shares the latest emergency response updates. Turn to these stations for the most current information:


Local radio stations provide up-to-date weather information. Tune in to them for the most current information.