El Niño and the UK Winter 2026/27: Prepare Your Garage

If your garage door lets in rain or you can feel a draught around the edges, winter tends to make both problems harder to ignore. Boxes get damp, the floor stays wet and a quick job in the garage becomes something you put off until the weather improves.

 

 

There’s been plenty of attention on what El Niño could mean for winter 2026/27. The forecasts give us a reason to check the garage now, but they don’t tell us exactly what weather your home will get. A few sensible checks will still be useful if the winter turns out milder than expected.

Start with water getting in, then look at draughts and whether the door needs insulation. We’ll take you through those checks below, along with how to choose the right GaraDry products for the gaps you actually have.

What does El Niño mean for the UK this winter?

El Niño is a warming of sea-surface temperatures in parts of the tropical Pacific. It can influence weather patterns well beyond that region, although its effect on the UK is less direct and harder to predict.

The Government Office for Science’s assessment updated on 17 September 2026 describes a significant event as likely towards the end of the year. It points to a slightly increased chance of storms and heavy rain from October to December, followed by a slightly increased risk of cold snaps early in 2027. The UK impacts remain uncertain.

That’s a shift in the chances, rather than a schedule for a wet autumn followed by a freezing January. The Met Office’s autumn outlook also stresses that El Niño is one of several influences on our weather. An unusually strong event doesn’t automatically mean unusually severe conditions here.

For a homeowner, the practical decision is fairly simple. If the garage already leaks or feels draughty, there’s little benefit in waiting for a more certain winter forecast before dealing with it. Use local forecasts and warnings for decisions about approaching weather. Our guide to preparing for UK storms covers the checks around the door in more detail.

Start with the rain: where is it getting in?

Before choosing a seal, find the route the water takes. A puddle by the door might come through the gap underneath, but it could also have travelled around a corner or down the frame. The place it collects isn’t always the place it enters.

Check during ordinary rain if you can do so safely, or look afterwards for wet edges and water marks. Pay attention to the bottom of the door, both corners, the side tracks and the frame above. Check nearby gutters and downpipes too, particularly if water is spilling onto the driveway.

 

Water under the door

Close the door and look along the floor line. Daylight underneath, a worn bottom strip or a dip in the concrete can leave a route for rain. Measure the gap at several points rather than relying on one reading in the middle.

A threshold seal is fixed to the floor behind the door and forms a raised barrier at the opening. It needs a continuous sealed bond underneath and a proper fit at the ends. Otherwise, water can go beneath or around it.

Water at the sides or top

Wind-driven rain can reach gaps around the edges as well as the bottom. Inspect existing seals for cracks, damage or places where they no longer make contact. On an up-and-over door, suitable top and side seals can help close those routes without preventing the door from moving.

For sectional and roller doors, check any open spaces between the wall and the side tracks. These may need foam side blocks so water cannot bypass the threshold. Follow the instructions for the particular installation and keep moving parts clear.

An uneven floor or water pooling outside

Flexible PVC can accommodate some floor unevenness, but a deep dip or damaged concrete may need attention first. The seal needs a sound surface to bond to. Adding more adhesive won’t repair loose concrete or make a badly uneven floor level.

If the driveway slopes towards the garage, look at what happens to the run-off. Clear existing drains and channels, then see whether water still collects at the entrance. Persistent pooling may need a drainage assessment. A taller threshold raises the barrier, but it doesn’t provide an outlet for the water.

A correctly fitted threshold can help with rainwater at the bottom of the door. It cannot protect against every source of flooding: water may overtop the barrier, pass around it or enter through walls or the floor. If your home has flooded or is at risk, use the GOV.UK flood preparation guidance alongside advice on drainage and property protection. The guide also links to the separate services for Scotland, Wales and Northern Ireland.

Before the next wet spell, these are worthwhile jobs:

• Clear leaves and debris from accessible drains and check that gutters and downpipes are working.
• Move cardboard boxes and vulnerable stored items off the floor.
• Inspect the seals and measure any gaps under the closed door.
• Keep air bricks and ventilation openings clear.

Our autumn and winter weatherproofing guide covers the wider seasonal checklist. If water is entering through the building rather than the door, have that defect assessed before buying a door seal.

Next, deal with draughts and heat loss

You may notice the cold most when you use the garage as a workshop, gym or utility space. In an attached or integral garage, the separation between the house and garage matters too. A cold garage can increase heat loss through the adjoining walls and internal door, depending on how well they are insulated.

Start by checking the gaps around the main garage door. Sealing those can reduce unwanted draughts. Then consider the panel itself: a thin metal door can still allow heat to escape even when its edges are well sealed.

Door seals and insulation do different jobs. Seals reduce air movement through gaps around the door; insulation reduces heat transfer through the door panel. Adding insulation alone leaves the gaps open, while sealing the edges doesn’t insulate the metal between them.

If you heat the garage or spend time in it through winter, improving both can be useful. For an unheated detached garage used mainly for storage, the benefit of panel insulation may be smaller. It won’t produce heat or guarantee a frost-free space. Our guide to deciding whether to insulate your garage door helps you weigh that up.

Keep ventilation in mind

There’s a difference between stopping rain blowing through the door and blocking the garage’s ventilation. Leave intended vents and air bricks open. Moisture from a wet car, leaks or other sources still needs somewhere to go.

Condensation depends on moisture, surface temperatures and ventilation, so draught-proofing alone isn’t a guaranteed cure. If tools or windows remain wet, investigate the source of moisture as well as the airflow. A garage can have a well-sealed door and still need better moisture control.

Check anything vulnerable to frost

Look at exposed water pipes and outdoor taps connected through the garage. Appropriate pipe insulation can help reduce freezing risk. If you’re unsure how to protect or isolate a supply, ask a plumber. Don’t assume that insulating the garage door will protect every pipe during a cold spell.

Which GaraDry products suit the job?

Choose products for the opening and the problem you’ve found. For a threshold, measure the width and the gap beneath the closed door in several places. Note the largest gap, any dips in the floor and whether water pools outside.

Our domestic PVC thresholds come in 15mm, 20mm, 25mm, 30mm, 40mm and 50mm heights. A greater height may be useful where a higher barrier is required, but you still need to check the fit, door operation and drainage. There isn’t one height that suits every UK winter.

The product pages have the current prices, sizes and kit contents. For threshold sizing, start with our buying guide. If the opening is awkward, contact us with measurements and photos of the door, floor and tracks. Those details help us give you useful advice before you order.

What does the insulation figure mean?

With the GaraDry insulation kit fitted using 2mm spacers, a garage door’s U-value drops from around 5.88 W/m²K uninsulated to 1.28 W/m²K. A lower U-value means less heat passes through for the same temperature difference.

That’s a reduction of around 78% in heat transfer through the door with 2mm spacers. It is not a 78% saving on household heating bills. The difference you notice depends on the door, other heat-loss routes and whether the garage is heated. Follow the kit’s fitting method rather than assuming any installation will achieve the same result.

Check vehicle suitability too

Domestic PVC thresholds and commercial aluminium thresholds have different uses. If you drive a heavy vehicle through the opening or it sees frequent traffic, check the specific product’s weight and usage limits. Our commercial door seals may be more suitable. Vehicle type alone isn’t enough to decide: weights vary considerably.

Choose a suitable day to fit your seal

It’s easier to do a careful fitting job when the surface is ready and the conditions suit the adhesive. Check the forecast before starting, rather than trying to finish just ahead of a downpour.

GaraDry Adhesive and Sealant has a recommended application range of 5°C to 35°C. Keep the cartridge at room temperature before use. Cure time is affected by conditions, so follow the product instructions rather than assuming the adhesive is ready as soon as it feels firm.

For our domestic PVC threshold fitting instructions, allow 24 hours before driving over the seal or testing it with water. Prepare the floor properly first: remove dirt, oil and loose material, and seal dusty or powdery concrete. Loose concrete or gravel won’t provide a suitable bond.

Position the threshold behind the door and check that the door closes, locks and operates normally before bonding. Pay particular attention to the ends, where a small remaining gap can let water around the barrier. Use the instructions for your chosen product for the full sequence.

Once fitted and ready to test, check for leaks with a gentle flow of water. Keep checking drains and seals through winter too. Leaves build up, and a new seal won’t clear a blocked gully outside.

Frequently asked questions

Will El Niño make winter 2026/27 wetter or colder in the UK?

The outlook suggests increased chances of wet and stormy conditions in autumn and early winter, and a possible greater risk of cold snaps later. These are uncertain seasonal signals, not a prediction for your address. Use current local forecasts and warnings when weather is approaching.

What height garage door threshold do I need?

Measure the gap beneath the closed door at several points and start with the largest reading. Consider water pooling outside, floor condition and whether the door can operate normally with the chosen profile. A sloping drive may need drainage as well as a seal.

Can I drive over a GaraDry threshold?

Check the limits for the particular product and your vehicle. Domestic PVC thresholds are intended for suitable domestic use; heavier vehicles or frequent traffic may call for a commercial aluminium threshold. Allow the specified fitting time before driving over a newly bonded seal.

Can I fit a garage door seal in cold weather?

The recommended application temperature for GaraDry Adhesive and Sealant is 5°C to 35°C. Choose suitable conditions for preparation and fitting, keep the adhesive at room temperature before use and follow the curing guidance. The domestic PVC instructions specify 24 hours before driving over or testing with water.

Will a threshold stop my garage flooding?

It can help stop rainwater entering at the floor line when correctly sized and fitted. Water can still overtop it, pass around it or enter elsewhere. Persistent run-off and wider flood risk need drainage or property protection advice alongside any door seal.

Is insulating my garage door worthwhile?

It may be worthwhile if you heat the garage, use it regularly in winter or want to improve a suitable metal door’s thermal performance. The benefit depends on the rest of the garage too. Insulation won’t close door-edge gaps, and an unheated garage won’t become warm simply because its door is insulated.

Should I make my garage airtight?

Keep intended ventilation openings clear. You can reduce unwanted draughts at the door while retaining ventilation for moisture control. If condensation persists, look for moisture sources and consider whether the existing ventilation is adequate.