Preparing for a solar storm means preparing for a prolonged power outage and communication disruption. The real threat isn’t radiation reaching the ground or electronics frying in your pocket. It’s the cascade of failures that follows when geomagnetically induced currents damage high-voltage transformers and knock out sections of the electrical grid. Your preparation should focus on self-sufficiency for days to weeks without electricity, reliable water, or cell service.
What a Solar Storm Actually Does
Two things happen when the sun erupts. First, a solar flare sends a burst of light and radiation that reaches Earth in about eight minutes, causing radio blackouts on the sunlit side of the planet. Second, a coronal mass ejection (CME) launches a massive cloud of charged plasma into space. That cloud takes one to three days to reach Earth, and it’s the one that causes the serious damage.
When a CME slams into Earth’s magnetic field, it generates electrical currents in long conductors like power lines, pipelines, and undersea cables. These currents can overheat and permanently damage high-voltage transformers, the kind that serve entire regions and take months or years to replace. A severe storm can also disrupt GPS signals, knock out satellite communications, and interfere with aviation navigation. The U.S. Geological Survey has noted that modern infrastructure is far more complex and interconnected than it was during past major storms, meaning one failure can cascade across multiple systems.
Your car, phone, and laptop are not going to be fried by a solar storm the way they might be by a nuclear electromagnetic pulse. Geomagnetic storms primarily affect very long conductors and equipment connected to the grid. Small personal electronics that aren’t plugged into the wall are generally safe. The problem isn’t that your devices break. It’s that the networks they depend on go down.
How Much Warning You’ll Get
NOAA’s Space Weather Prediction Center issues watches one to three days before an expected geomagnetic storm, giving you a preliminary window to act. Once a CME is confirmed heading toward Earth, warnings go out with a lead time of minutes to a few hours before impact. That’s not a lot of time if you haven’t prepared in advance, but it’s enough to unplug sensitive electronics, fill bathtubs with water, and top off your gas tank.
Solar activity follows an 11-year cycle, and we’re currently near the peak of Solar Cycle 25. NOAA’s prediction panel expected this cycle to peak around July 2025, with the window of maximum activity stretching from late 2024 through March 2026. During this peak, the probability of major storms is highest, making now a particularly good time to prepare.
Build a Power Outage Kit
The federal government’s emergency preparedness guidelines form a solid starting point. At minimum, you need:
- Water: one gallon per person per day for at least several days, stored for both drinking and sanitation
- Food: a several-day supply of non-perishable items and a manual can opener
- Light and communication: flashlights, extra batteries, and a battery-powered or hand-crank radio (ideally a NOAA Weather Radio with tone alert)
- First aid kit plus any prescription medications you take regularly
- Cash: ATMs and card readers won’t work without power
- Important documents: copies of insurance policies, IDs, and bank records in a waterproof container or on an encrypted USB drive
- Cell phone with a portable battery pack
Beyond the basics, think about what a two-week blackout would look like in your specific situation. If you have infants, stock formula, bottles, and diapers. If you have pets, set aside extra food and water for them. Keep a sleeping bag or warm blanket for each household member, a full change of clothes, sturdy shoes, and personal hygiene supplies. Matches in a waterproof container and a fire extinguisher round out the kit.
The often-overlooked items matter most in an extended outage: paper maps of your local area (GPS may be unreliable), a whistle for signaling, paper and pencils, and games or books for children. Boredom and anxiety during a multi-day blackout are real problems, especially for families.
Plan for Communication Failures
Solar storms hit radio communications hard. High-frequency (HF) radio, which operates between 1 and 30 megahertz, is especially vulnerable. Changes in the upper atmosphere can degrade or completely block HF signals, particularly on the sunlit side of Earth and at high latitudes during auroral activity. If you rely on shortwave or amateur radio as a backup communication plan, understand that it may be unreliable during the peak of a storm.
Cell towers typically have battery backup for a few hours, and some have generators, but a widespread grid failure lasting days will eventually take most of them offline. Satellite phones may also experience disruptions depending on the storm’s severity. Your most reliable option is a hand-crank NOAA Weather Radio, which receives broadcasts from transmitters with their own backup power. For reaching family members, agree on a physical meeting point in advance rather than depending on any electronic communication method.
Protect Your Home Systems
The biggest risk to your home electronics during a solar storm comes through the power grid, not through the air. Geomagnetically induced currents travel along power lines and enter your home through the wall outlet. Whole-house surge protectors, installed at your electrical panel, offer a meaningful layer of defense. Quality point-of-use surge protectors on expensive equipment like computers and home servers add another layer.
When a severe geomagnetic storm warning is issued, the simplest and most effective step is to unplug electronics you want to protect. Pull the plugs physically from the wall. A powered-off device that’s still connected to an outlet can still be damaged by a voltage surge. If you have a generator, make sure it’s fueled and tested before storm season. Solar panels with battery storage can keep critical systems running, but grid-tied solar systems without batteries will shut down when the grid goes down.
You don’t need a Faraday cage for a solar storm. That’s a precaution more relevant to nuclear electromagnetic pulse scenarios, where the energy burst is sudden, intense, and travels through the air to induce currents in short wires and circuit boards. A CME-driven geomagnetic storm works differently, generating slow-moving currents in very long conductors. Your phone sitting on the counter is not an antenna for that kind of energy.
Water and Sanitation Backup
Municipal water systems depend on electric pumps. If your area loses power for more than a day or two, water pressure will drop and may stop entirely. If you’re on a well, your pump won’t run without electricity. Fill bathtubs, large containers, and clean trash cans with water as soon as a storm watch is issued. Water purification tablets or a portable filter are worth keeping in your kit for longer outages.
Sanitation becomes a serious concern quickly. Without running water, toilets won’t flush unless you pour water into the bowl manually. Stock garbage bags, plastic ties, and a supply of moist towelettes. If you have a yard, know the basics of digging a temporary latrine as a last resort for an extended outage.
What the Grid Looks Like After a Major Storm
North American power utilities are required to assess their vulnerability to geomagnetic disturbances under reliability standards set by NERC, the organization that oversees grid reliability. These standards apply to high-voltage transformers above 200 kilovolts and require utilities to model what happens when geomagnetically induced currents flow through their equipment. Utilities must also develop plans to mitigate damage.
That said, the sheer scale of a worst-case storm creates challenges no regulation fully solves. Large power transformers are custom-built, weigh hundreds of tons, and can take 12 to 18 months to manufacture and install. If dozens are damaged simultaneously across a region, restoration won’t happen in days. Realistic planning means being ready for an outage that lasts one to two weeks in a moderate scenario, and potentially longer in a severe one. The people who fare best are those who treat solar storm preparation the same way they’d treat preparation for any extended natural disaster: stockpile essentials, reduce dependence on the grid, and have a plan that doesn’t require a cell phone to execute.