El Niño Winter 2026-27: What It Means for Your Garage
After a night of heavy rain, you open the garage to a wet floor and boxes with soft, dark bases. Farther north, it's snow melt running under the door and freezing there overnight.
Good garage door flood protection starts with how the water gets in, and that isn't always the gap under the door. Water also comes around the corners, collects in a dip in the slab or runs down a sloping driveway.
Forecasters give high odds of a very strong El Niño this winter, which tends to tilt the southern US wetter. It's a reason to check the garage this fall, not a forecast for your street.
Below, we'll cover what the outlook means for your region, how to find the water's route, and when a seal, drainage or a flood plan is the answer. As we manufacture garage door threshold seals, we've included a separate product section later in this guide. For the wider picture, see our flood prevention guide.
What could El Niño mean for your garage this winter?
El Niño, a warming of the tropical Pacific, can shift storm tracks over North America. In its ENSO diagnostic discussion issued September 10, NOAA's Climate Prediction Center (CPC) gives a very strong event this winter a greater than 90% chance, and a 75% chance that October to December is the strongest since 1950.
Its seasonal outlook discussion of September 17 adds that typical impacts are "larger, but they are not guaranteed." That's a shift in the odds for a season, though an unusual North Pacific pattern may soften the effects.
| Region | What the CPC outlook favors | What to check at your garage |
|---|---|---|
| Southeast and eastern Gulf Coast | Wetter, up to 70% to 80% over southern Georgia and northern Florida from November onward. | Runoff pooling at the door. |
| Southern California and the Southwest | Wetter, 50% to 60% near the California coast from December onward. | Driveways falling toward the garage. |
| Southern Plains, Mississippi and Tennessee Valleys | Wetter, 40% to 50% over the southern Plains. | Drains and the gap under the door. |
| Mid-Atlantic to New England | Wetter, from fall in the Mid-Atlantic and late fall farther north. | Wind-driven rain at the corners. |
| Northern tier, interior Northwest and Great Lakes | Warmer (50% to 60%), tilting drier in the interior Northwest and Great Lakes. | Melt refreezing at the door. |
A warmer north still means melt that refreezes at the driveway's lowest point, often the door. Our snow melt guide covers it, and new CPC outlooks are due in mid to late October.
First, find where the water is getting in
Before you buy anything, find the first point where water appears. A puddle mid-floor shows where water collected, but it may have entered at a corner.
If it's safe, watch from inside during ordinary rain: the bottom of the door, both corners, the frame and the walls. Water through the walls or slab won't be stopped at the door. In the north, look for ice along the door line after a thaw.
On a dry day, run a gentle hose over one small area at a time, starting at floor level, while someone inside watches. Skip the pressure washer. A hose check won't reproduce a long storm or a driveway full of runoff.
| What you notice | What to check | What may help |
|---|---|---|
| Water along the bottom of the door | A gap under the door or a worn bottom seal. | A threshold seal sized to the largest gap. |
| Water at one low point | A dip in the slab or a door that isn't level. | Small irregularities are handled at fitting; deeper dips may need repair. |
| Water at a bottom corner | The threshold ends, the frame or a gap beside the side track. | Sealed ends and foam side blocks. |
| Ice at the door after a thaw | Melt running down the driveway and refreezing. | Clear snow back and check how the driveway falls. |
| Water pooling across the opening | A blocked drain, a downspout near the door or a sloping driveway. | Clear drains, redirect downspouts or get drainage assessed. |
| Damp walls or water through the floor | High outside ground, cracks or groundwater. | Get the building and grading checked first. |
Treat these as clues, since more than one route can be involved, and keep vents clear.
What if your garage floor is uneven?
Close the door and look along the bottom edge from inside. Daylight in the middle with contact at both ends usually means the slab dips, or the door sits lower on one side.
Measure the gap at several points, including any low spots, and note the largest reading. A bottom seal on the door moves with it and can't fill a low spot in the floor.
A flexible PVC threshold bonded behind the closed door can handle some unevenness, provided the bond underneath is continuous. Our ¾ inch seal is made for floors or doors that aren't level, because the extra height helps it seal across the full width.
For a deep dip, crumbling concrete or wide cracks, repair the slab first. Adhesive won't fix an unsound surface, and a taller seal can stop the door closing. A driveway sitting higher than the garage floor is a grading job, covered below.
Don't overlook the corners and side tracks
Wet corners after a threshold has been fitted often mean water is getting around its ends, and wind-driven rain finds them easily.
On many sectional doors the side tracks stand off the wall, leaving a gap at each end. Our foam side blocks cut to fit between track and wall and bond with the adhesive. If you set the 2 inch Garadam back behind the tracks, you may need our Garadam side blocks so water doesn't build up and spill around its ends.
Notch the threshold around the frame or tracks so it sits tight against the back of the door, and seal the ends. Water running down the frame or wall from above is a building repair to sort out first.
When drainage, grading or a flood plan is the answer
A threshold helps with water at the opening, but it doesn't give that water anywhere to go. If water pools outside, clear any drain by the door and make sure downspouts empty well away from the garage.
If that doesn't solve it, or the driveway slopes toward the garage with no drain, ask a qualified contractor to assess the levels. A drain across the entrance with a proper outlet, regrading or, for water rising through the slab, a sump may be needed.
A threshold seal is a barrier at the floor line. Water can still get in if it rises above the seal, passes around its ends or finds another route through the walls or slab. Pair it with drainage where the drive falls to the door.
If your home has flooded before or sits in a flood-prone area, the ready.gov flood page explains how to make a household plan. It notes that a flood insurance policy typically takes up to 30 days to go into effect, so look into cover well before the wet season. FEMA's FloodSmart site covers the National Flood Insurance Program. Before the first big storm, move valuables off the garage floor.
Choosing the right GaraDry threshold seal
Start with the opening. Measure the width and the gap under the closed door at several points, then note the largest reading and how much water collects outside. Our guide to measuring for a threshold seal walks through it.
Our residential threshold seals come in ½ inch, ¾ inch, 1 inch, 1¼ inch and 1½ inch heights, with the 2 inch Garadam as the tallest. Bonded with our adhesive, each holds water back to its own height. A taller seal needs room for the door to close normally.
| Option | Where to start | What else to check |
|---|---|---|
| ½ inch to 1¼ inch residential seals | Compare the heights with your largest gap. The ¾ inch suits floors or doors that aren't level. | Floor condition, door clearance and sealed ends. |
| 1½ inch water barrier and 2 inch Garadam | Where a higher barrier is needed and the opening allows it. | The Garadam is heavy in longer lengths, so plan on two people to carry one. |
| Aluminum thresholds | Heavier vehicles or frequent traffic. | The fitting method for that threshold. |
| GaraMat containment mats | Snow and slush dripping off a parked vehicle. | The mat size for your vehicle. |
Our residential seals have a 6,000 lb weight limit, suitable for most cars and small vehicles, so check your vehicle's weight first.
You'll find current lengths, prices and kit contents on our product pages, and our threshold buying guide helps narrow the options. If you're unsure, contact us with your measurements and photos of the door, floor and any side tracks. That gives us a clear picture of the opening you're sealing.
Fit it on a mild, dry day before the cold sets in
Apply our adhesive at 40°F to 95°F, with the cartridge kept at room temperature. Below 40°F it gets hard to work with, and in the northern states that window can close quickly as fall goes on, so pick a mild, dry day.
Clean away dust, dirt, oil and grease, and wire-brush any loose paint. Dusty or powdery concrete needs a concrete sealer first, and loose concrete or gravel isn't suitable. Dull smooth epoxy or tile with low-grit sandpaper, and lay the threshold flat beforehand so it relaxes.
With the door closed, set the threshold against it and check that the door shuts, locks and, if it's automatic, opens normally. Apply the adhesive in two parallel lines with a zigzag between them, press the threshold down and seal the ends.
Leave it to dry overnight before driving over it, then test with a bucket of water, with someone inside watching the ends. Our installation instructions and GaraDry Adhesive and Sealant page have the full detail.
Frequently asked questions
Will El Niño make this winter wetter where I live?
It shifts the odds without deciding them. The CPC's September outlook favors a wetter season across the southern US and up the Atlantic coast, and a warmer one across the northern tier. New outlooks are due in mid to late October, so check your local forecast too.
How do I stop water coming under my garage door?
Find the route first: the gap under the door, a dip in the floor, the corners or a sloping driveway. A threshold seal bonded behind the closed door closes the floor-line gap. Pooling water outside needs clear drains and downspouts as well.
What height threshold seal do I need?
Start from the largest gap under the closed door, measured at several points. Then consider the water that collects outside and whether the door still closes normally. Our residential seals run from ½ inch to the 2 inch Garadam, and the ¾ inch suits uneven floors.
Will a threshold seal stop my garage flooding?
A correctly fitted seal holds back water at the floor line up to its own height. Water rising above it, passing around its ends or coming through the walls or slab needs drainage, grading or a household flood plan as well.
Can I fit a threshold seal in cold weather?
Only within our adhesive's 40°F to 95°F application range, on a clean, sound surface, with the cartridge kept at room temperature. Leave it to dry overnight before driving over the threshold, then test it with water, so pick a mild, dry spell this fall.