Solar Flares Hit: RimWorld Survival Tricks That Work

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Solar Flare 101: Mechanics & Effects

What is a Solar Flare?

A Solar Flare is a random map-wide event where an intense electromagnetic burst from the sun shuts down all electrical devices on the planet. In game terms, the event text says: "The intense radiation will shut down all electrical devices. It should pass in about a day."

Why Solar Flares Are Dangerous

Food & Freezer
Hydroponics
Defense
Climate Control

Food Spoilage & Freezer Meltdowns

When a solar flare hits, freezer coolers shut off and temperature starts equalizing with the outside. In warm biomes, a freezer can rise above 0°C in just a few hours, starting the countdown to food spoilage.

RimWorld freezer design featuring double-wall insulation for efficient temperature control

RimWorld freezer design featuring double-wall insulation for efficient temperature control.

💡 Pro Tip: Double-wall your freezer and use two doors (airlock). This can keep it below 0°C nearly twice as long during a flare!

Emergency Actions:

  • Forbid the freezer door so pawns don't go in and out
  • If outside is cold (below freezing), consider moving food outside or unroofing the freezer
  • Cook or preserve food immediately (cooked meals last longer unrefrigerated)
  • Use packaged survival meals or pemmican as backup food sources
  • For advanced base layout strategies including freezer design, see our colony layout guide

Early-Game Survival Strategies

The early game (first year or two) is actually one of the simpler times to deal with solar flares, because you aren't hyper-dependent on electricity yet.

Mid-Game Strategies

By mid-game, you have a solid base with power, perhaps some automation, and more colonists. This is when solar flares go from minor setback to serious event if you haven't built in safeguards.

Smart Battery Placement For RimWorld Solar Flare Preparedness

Smart Battery Placement For RimWorld Solar Flare Preparedness

Late-Game & Extreme Scenarios

In late-game, your colony might be a gleaming techno-fortress with advanced power systems and armies of bots – or a sprawling kingdom. Solar flares remain a threat, but you have resources to nullify their impact.

RimWorld base featuring solar panels, a wind turbine, and battery storage for power management

RimWorld base featuring solar panels, a wind turbine, and battery storage for power management.

Spread Out Risk

Split resources into multiple rooms. Have two smaller freezers instead of one giant one. Compartmentalize hydroponics into separate chambers.

Triple-Wall Everything

Go beyond double walls for critical infrastructure. Create freezer foyers as temperature buffers. Use high thermal mass materials like stone.

⚠️ Warning: If you're launching your ship (15-day reactor sequence), solar flares can still occur! Prepare backup defenses and have your best fighters ready with high-tier weapons.

Royalty DLC Considerations

EMI Dynamos & Mech Clusters

The Royalty DLC introduces Mechanoid Clusters which sometimes include an EMI Dynamo – a device that simulates a permanent solar flare until destroyed. This is even more dangerous than a normal flare because it won't end on its own.

💡 Pro Tip: Use sniper rifles or cloaking to take out EMI dynamos quickly from a distance!

Psycasts to the Rescue

Royalty's psycasts (psychic powers) are not affected by solar flares! Use these abilities during emergencies:

  • Skip to reposition fighters when turrets are down
  • Berserk Pulse to turn raiders against each other
  • Solar Pinhole provides light and heat during flares
  • Vertigo Pulse to control crowds without turrets

Ideology DLC Considerations

Ideoligion Precepts & Solar Flares

Precept Impact During Solar Flare
Darkness: Disliked Colonists will get mood debuffs at night; prepare torch lamps
Darkness: Preferred Mood boost during flares - one of the few upsides!
Technophobe Meme Solar flares are a non-issue - your tribe already functions without electricity
Transhumanist Meme Extra mood hit when losing tech comforts; compensate with rituals

Unusual Events: If the "Unnatural Darkness" event is active (from Anima tree or certain relics), solar flares strangely have no effect! The electronics keep working despite the flare.

Biotech DLC Considerations

Mechanitors & Mechs

+

Growth Vats & Life Support

+

Sanguophages and Deathrest

+

Mods and Advanced Tools

If you're open to mods, solar flares go from "unbeatable force of nature" to "configurable challenge." Here are some popular options:

RT Solar Flare Shield

Compatibility: 1.0–1.4

Adds a late-game magnetic shield that activates during flares to protect your electronics. Uses 25,000W power when active and generates extreme heat.

RT Solar Flare Shield Mod

"No Solar Flares" Mod

The blunt solution: simply removes solar flares from the game's incident list. Makes turret-reliance easier but removes a challenge source.

Balanced Solar Flares

Adjusts frequency and impact of flares. Makes them rarer but possibly longer. Some versions reduce effects under mountains.

Vanilla Power Expanded

Adds Helixien gas extraction and gas-fueled lamps, heaters, etc. During a flare, these gas appliances keep working!

Scenario Editor: Without mods, the game's Scenario Editor allows you to disable incidents completely. You can remove Solar Flare from the incident list when setting up a new game.

Quick-Start Survival Checklist

Follow this checklist to dramatically improve your colony's resilience to solar flares:

Before a Flare
During a Flare
After a Flare

Preparation Checklist

Frequently Asked Questions

Can you prevent a solar flare in RimWorld?

Not in unmodded gameplay – there's no way to stop or shorten a solar flare. You can only prepare to mitigate its effects. Mods like "RT Solar Flare Shield" or scenario settings are needed to prevent them entirely.

How long do solar flares last?

Solar flares typically last between 0.15 and 0.5 days (about 3.6 to 12 hours). Extreme cases might approach 24 hours, but longer is very rare.

Do solar flares kill mechanoids or pawns with bionics?

No, colonists and mechanoids aren't killed by the flare itself. Enemy mechanoids remain fully operational. Your controlled mechanoids just become uncontrollable temporarily, and bionic parts in colonists are unaffected by flares.

Will my freezer food spoil during a flare?

It depends on how well insulated your freezer is and the outside temperature. A double-walled freezer can stay below freezing through most flares. Extremely hot biomes might see faster warming. Best practice is to forbid the freezer door immediately when a flare hits to preserve cold.

Do hydroponics plants die during a flare?

Yes, plants in hydroponics basins will start dying within a few hours of a flare starting. Unlike soil-grown plants, they die without power. Harvest them immediately when a flare begins, even if not fully grown, to salvage some yield.

Conclusion: Embrace the Chaos

Solar flares in RimWorld are one of those events that can feel really punishing, but they're also an opportunity for emergent storytelling. They force us to get creative and have backup plans. The famous RimWorld player mantra is: "Hope for the best, plan for the worst." If you've read this guide, you've planned for the worst a solar flare can throw at you.

When the next flare hits, you'll calmly zoom out and observe: your colonists are already moving emergency rations to a safe spot, your base's vital areas are aglow with torchlight, your muffalo army is positioned at the gates, and your hydroponics plants... well, they're still dying, but hey, you planted extra potatoes in soil as backup this time. 😉 In short, your colony will survive, and perhaps even treat it like a day off normal routines.

Keep in mind that Randy (and even Cassandra) have a cruel sense of humor. You might get a flare during a raid and a heat wave and an eclipse simultaneously. But with the knowledge and preparation from this guide, those compound disasters are exactly when epic stories are born. Some colonies will fold, but yours will adapt and come out stronger.

"In the darkness, the colony found its light." 🔦

Interactive Tools

Freezer Survival Calculator

Estimate how long your freezer will stay frozen during a solar flare:

Last updated: June 2025 | This guide covers RimWorld up to version 1.5

Created by RimWorld veterans for the community

Stay warm out there!