Columbia Sportswear - Your backpack might be water resistant, but using a rain cover will give an layer of protection between your stuff and the elements. Backpack rain covers are made from
HELD- Adventure Evo Motorcycle Backpack With Rain Cover 28 Litre Black | eBay
OEX Vallo Air 36 Rucksack with Ventilated Back System and Integrated Rain Cover | eBay
Black Diamond Unisex Street Creek 20 Backpack on OnBuy
TECHNICALS Waterproof Tibet 55 Litre Rucksack with an Integrated Raincover and Water Resistant Top Lid, 55L Backpack, Travel Pack, Travel Bag, Hiking on OnBuy
Thule Backpack Rain Cover | Thule | United Kingdom
BOOTSTRAPT 15 in. Contractor's Backpack with Integrated Power Bank Compartment and Waterproof Rain Cover 006-550 - The Home Depot
ABUS Rain Cover for Backpacks - Lumino X-Urban Cover with Integrated USB Rear Light - Waterproof & Visible Backpack Cover - Yellow/Silver : Amazon.co.uk: Fashion
Offroad Hiker backpack 20L Red for DSLR/CSC - MB OR-BP-20RD | Manfrotto Global
BE VISIBL - Universal raincover with LED lighting - Port Designs
oex Vallo Air 36 Rucksack with Ventilated Back System and Integrated Rain Cover, 36 Litre Hiking Rucksack, 36 Litre Hiking Backpack, Blue, One Size : Amazon.co.uk: Sports & Outdoors
OEX Vallo Air 36 Rucksack with Ventilated Back System and Integrated Rain Cover, 36 Litre Hiking Rucksack. 36 Litre Hiking Backpack, Travel Bag, Blue, One Size : Amazon.co.uk: Sports & Outdoors
Creator's Road Mentor – Crumpler UK
Drifter Sport North 14" Laptop / Tablet Backpack with Rain Cover- Black/Grey
OEX Vallo Air 36 Rucksack with Ventilated Back System and Integrated Rain Cover | eBay