We may earn a commission when you buy through links on this page, at no extra cost to you. It never decides what we recommend. How we make money
Can you jump start a car in the rain? Yes, in ordinary rain you can, as long as you follow the same steps you would on a dry day. A car’s 12-volt system does not become a shock hazard because it is wet. What rain does change is the gear: some portable jump starters are rated for wet weather and some say plainly not to use them in rain at all.
This guide is for US drivers stuck with a dead battery in wet weather, whether you are using a portable jump starter or jumper cables. We checked what five jump starter makers say about rain, then added official guidance on lightning and flood-damaged cars. You will learn when it is fine to go ahead, when to wait, and how to keep a pack working when it is pouring.
Can you jump start a car in the rain? Quick answer
- Light or steady rain Yes. The 12V system is low voltage, so the steps are the same as on a dry day. Use a pack its maker allows in wet conditions.
- Thunder or lightning No. Wait inside the car until 30 minutes after the last thunder, as the National Weather Service advises.
- Car sat in flood water No. Do not try to start it; have it inspected first.
- Your pack Check its manual. Clore says its JNC305 can be used in rain, NOCO rates its Boost packs IP65, and DeWalt says not to use its units in rain or snow.
What rain actually changes when you jump start a car
Most people worry about getting shocked. That is not the real issue. Kelley Blue Book says the battery’s voltage is not high enough for rain to make the job more dangerous than it is on a dry day. The risks that do matter are the ones that exist in any weather, plus a few that wet conditions make worse:
- Sparks near the battery. Clore’s manual warns that lead-acid batteries release explosive gases during normal operation, charging and jump starting, and can explode in the presence of sparks. Rain does not change that, so the connection order still matters most.
- Water getting into the jump starter. A pack is electronics in a case. Whether it can take rain depends on how its maker built and rated it, which is why the next section matters.
- Lightning. The National Weather Service says there is no safe place outside when thunderstorms are in the area. Standing at an open hood counts as outside.
- Traffic, footing and visibility. Wet roads, poor light and slippery ground make a roadside jump riskier than the electricity does.
Can you use a jump starter in the rain? What the makers say
This is where most advice online stops short. Jump starter makers do not agree, and a few say the opposite of “it’s fine.” Here is what each manual or support page we checked says about water:
| Jump starter | What the maker says about water | Use it in the rain? |
|---|---|---|
| Clore Jump-N-Carry JNC305 | Can be used in any weather, including rain and snow; do not submerge | Yes, per the manual |
| NOCO Boost (GB20, GB40) | Rated IP65 with port covers closed; can be exposed to water but not submerged | Yes, with port covers closed |
| DeWalt (DXAEJ14, DXAEPS14) | Do not use in damp or wet locations or in rain or snow; never use when wet | No |
| AstroAI S8 | Do not store or use in humid environments | No, by the manual’s wording |
| Battery Tender 600A | No water rating found on the product page or in the manual | Not rated; keep it dry |
Sources: Clore’s JNC305 manual, NOCO’s Boost FAQ, DeWalt’s DXAEJ14 and DXAEPS14 manuals, AstroAI’s S8 manual and Battery Tender’s 600A manual. If your pack is not listed, search its manual for “rain,” “wet,” “moisture” or an IP rating before you use it outdoors in bad weather.
Reading an IP rating
IP65 = 6 for dust + 5 for waterThe IEC’s IP code uses two numbers. The first grades protection against solids on a scale up to 6, which means no dust gets in. The second grades protection against liquids on a scale from 0 to 9. NOCO’s IP65 sits at the top for dust and in the middle for water, and NOCO explains it as safe to expose to water but not to submerge. So rain is fine with the port covers shut; a puddle is not.
Rain, storm or flood: when to go ahead and when to wait
We turned the makers’ rules and official weather guidance into one table. Find your situation on the left.
| Situation | Go or wait? | Why |
|---|---|---|
| Drizzle or light rain | Go ahead | Same steps as a dry day; keep a non-rated pack shielded |
| Steady or heavy rain | Go ahead with care | Use a pack rated for wet use, keep ports closed and the pack off wet ground |
| Thunder or lightning nearby | Wait | NWS: no safe place outside; shelter in a hard-topped vehicle with windows up |
| Car stalled in or parked in flood water | Do not start it | State Farm: starting a flooded car can cause serious damage |
| Your pack’s manual says no rain or humidity | Wait or shield it | Use it only where it stays dry |
| Hybrid or electric car | Follow the owner’s manual | Use only the 12V jump points it names, rain or shine |
On lightning, the National Weather Service advises moving into an enclosed, metal-topped vehicle with the windows up and staying sheltered for at least 30 minutes after the last thunder. A dead battery does not stop the car from being a shelter, so wait inside it. On flooding, State Farm says not to start a flooded car, even if it seems dry, and to have it inspected first. A jump start will not fix water in the engine.
How to jump start a car in the rain, step by step
The sequence is the same one in our guide on how to use a jump starter. These are the rain-specific additions, all drawn from the manuals above:
- Check the sky first. If you hear thunder, stay in the car and wait.
- Make the car safe. Turn on your hazard lights, set the parking brake and switch off the ignition, lights and accessories.
- Get the pack ready while it is dry. Close any port covers; NOCO’s IP65 rating only applies with them closed. Keep the pack off wet ground and out of puddles, and keep it out of the rain entirely if its manual does not allow wet use.
- Connect red first. With the pack off, clamp red to the positive (+) terminal.
- Connect black to bare metal. Clore’s manual says to use an unpainted part of the chassis or a non-moving metal engine part, and never a fuel line. This keeps any spark away from the battery’s gases.
- Turn the pack on and start the car. Keep cranking short and follow your pack’s rest times. If a light or beep appears, our jump starter error light guide explains what it means.
- Disconnect in reverse order. Black first, then red, and close the hood.
- Dry and recharge the pack later. Wipe it dry and let it reach room temperature before you recharge it, inside the maker’s charging range: 32°F to 104°F for NOCO and 32°F to 108°F for Clore.
Shopping for a pack you can use in bad weather? The Clore JNC305, the one pack here whose manual says it can be used in rain, is a pick in our best jump starter for small cars guide. Riders caught out in the wet will find the same battery-type and weather checks in our best motorcycle jump starter guide.
Jumper cables in the rain: same rules, more exposure
Jumper cables work in the rain for the same reason a pack does: the 12-volt system is low voltage. The difference is time and space. You need a second car parked close, two hoods open and more time standing in the weather, and the donor car’s running engine adds moving parts to work around. A portable pack lets you do the job from one side of one car. Our comparison of jump starter vs jumper cables covers the other trade-offs.
With cables, keep both clamps of each cable apart, never let a clamp rest on wet bodywork, and make the last connection to bare metal on the dead car, away from the battery.
Jump starting a car in the rain: myth vs fact
| Myth | Fact |
|---|---|
| Water and a car battery mean you can get electrocuted. | Kelley Blue Book says the battery’s voltage is not high enough for rain to make jump starting more dangerous than on a dry day. |
| Every jump starter is fine in the rain. | DeWalt says not to use its units in rain or snow, and AstroAI says not to use the S8 in humid environments. |
| IP65 means waterproof. | NOCO says IP65 packs can be exposed to water but not submerged, and only with the port covers closed. |
| A car is unsafe to sit in during a storm. | The National Weather Service lists an enclosed, metal-topped vehicle with the windows up as shelter from lightning. |
| A car that sat in a flood just needs a jump. | State Farm says not to start a flooded car at all until it has been inspected. |
Frequently asked questions
Is it safe to use a jump starter in the rain?
Is it safe to jump a car in the rain?
Can you jump start a car in a thunderstorm?
Can I start a car if the battery is wet?
Can you get shocked jump starting a car in the rain?
Can you use jumper cables in the rain?
Can you jump start a car in the snow?
How we researched this guide
To answer whether you can jump start a car in the rain, we read the manuals and support pages of five jump starter makers for anything they say about water, rain, snow, humidity and IP ratings, and checked the connection steps they give. We added lightning guidance from the National Weather Service, flood guidance from State Farm, Kelley Blue Book’s advice on rain, and the IEC’s explanation of IP ratings. The go-or-wait table and the myth-vs-fact table are our own summary of those sources. We did not hands-on test any product, and no brand paid for or reviewed this article.
Sources: Clore JNC305 manual · NOCO Boost FAQ · DeWalt DXAEPS14 manual · AstroAI S8 manual · Battery Tender 600A manual · NWS lightning safety · NWS lightning tips · State Farm: flood-damaged cars · Kelley Blue Book: how to jump start a car · IEC: IP ratings
Researched by Shahzad
Amazon seller who researches products using sales-rank history, price tracking and owner reviews before recommending anything. Read our disclosure.