Why Gloomy Weather Might Be the Perfect Time to Cast Concrete Outdoors

If you've been holding off on starting your next concrete project using our Cast-In-Place Mix because of the recent grey skies, we’ve got good news: slightly gloomy weather can actually be ideal for casting concrete outdoors. At Concrete Lab, we’re always looking for the perfect balance between craftsmanship and conditions—and this is one of those rare moments when the weather works in your favour.

Mild Conditions = Better Curing

Unlike the peak of summer, where strong sunshine and high temperatures can cause concrete to dry out too quickly, cooler, overcast weather helps concrete cure more effectively. That’s because concrete doesn’t just dry—it cures, a chemical process that requires moisture to strengthen properly.

When the weather is mild and the sun’s not beating down, your mix is less likely to lose moisture too fast. This reduces the risk of cracking and helps the concrete achieve its full strength and durability.

More Time, Less Stress

One of the main challenges with casting concrete in hot weather is timing. Higher temperatures speed up the setting process, which can put you under pressure—especially for larger pours or more intricate moulds.

With cooler weather, you get a longer working time. That means more time to pour and finish your surface without feeling like you’re racing the clock.

But Watch Out for Rain…

Of course, not all gloomy weather is created equal. Rain and wet conditions are not your friends when it comes to casting concrete outdoors. If there’s a chance of rain during your pour—or even shortly after—you’ll want to protect your workspace.

We recommend covering your project area with a popup gazebo, tarpaulin, or similar shelter. This helps prevent rain from disrupting the surface or diluting the mix, which can weaken the final result. It’s especially important to keep water off the surface before the concrete has had a chance to set.

Top Tips for Casting Concrete in Cooler Weather

• Monitor the forecast: A dry, cloudy day is perfect. If rain is due, wait or protect your setup.
• Use high-quality concrete mixes: Our pre-blended mixes at Concrete Lab are ideal for outdoor casting and offer excellent workability in all seasons—no vibration required.
• Don’t skip the prep: Make sure your moulds, tools, and workspace are ready to go before you mix.
• Cover and cure: After pouring, consider lightly covering your concrete with plastic sheeting to retain moisture.

Thinking About Starting a Concrete Project? Now’s the Time.

Whether you’re making a concrete worktop, garden planter, or decorative piece, this cooler spell is a great opportunity to get cracking—without the stress of summer heat.

Need help picking the right mix or tools for your outdoor pour? Get in touch with the team at Concrete Lab, or browse our range of concrete products designed for DIYers, makers, and pros alike.