Updated: July 2025
The UK has seen several unexpected heatwaves in recent years — and July 2025 is no different. For anglers, these temperature spikes can make or break a session. But how exactly do fish behave in extreme heat? Should you change your tactics or avoid fishing altogether?
In this guide, we’ll break down how heatwaves affect fish activity and how you can still catch during the hottest days.
Do Fish Feed Less in Hot Weather?
Yes — but not always.
When water temperatures rise above normal, oxygen levels drop, especially in still waters. This can make fish lethargic, less willing to chase, and more prone to staying near shaded or deeper zones. In canals and lakes, you may notice fewer surface swirls and less movement during midday.
However, certain species like carp, chub, and perch still feed actively — you just have to change your approach.
Signs of Fish Activity During a Heatwave
- Fish cruising just under the surface
- Bubbling near shaded margins (especially early morning)
- Sudden bites right after sunset
- Fish shoaling around deeper features or aerated spots
If you’re seeing nothing on the surface during peak heat (12–4 PM), don’t panic — they’re likely holding deeper or inactive temporarily.
Best Times to Fish During a Heatwave
- Early Morning: 4:30 – 8:00 AM
- Late Evening: 7:30 – 10:00 PM
- Overnight (for carp anglers): Dusk to dawn
Avoid midday unless you’re targeting heavily shaded river swims or deeper gravel pits.
Best Baits to Use in Hot Weather
- Slow-sinking pellets or light groundbait
- Bread flake for surface cruising carp or chub
- Worms or maggots for bottom-feeding fish
- Boilies with high-leakage flavours (for carp)
Go for smaller portions and avoid overfeeding — fish won’t eat as heavily when stressed.
Tactics That Work in a Heatwave
- Stalking Carp in the Margins: Use bread or small pop-ups
- Surface Fishing with Floating Baits: Great for afternoon when fish are cruising
- Feeder Fishing in Deep Water: Reach cooler zones where fish are resting
- Drop Shot for Perch in Shaded Canals: Tight to structure or boats
Final Thoughts
Fishing during a UK heatwave doesn’t mean you’ll blank — but you need to adapt. Focus on timing, location, and lighter baiting. The fish are still there, but they’re picky, pressured, and often sluggish during the hottest hours.
If you fish smart, early, and light — there’s still great sport to be had this summer.
