The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A browner version of the original weathered fence texture.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A textured orange background pattern with vertical stripes.
Source V. Hartikainen
A free seamless background pattern for use on websites.
Source V. Hartikainen
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso