Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
A seamless background of warped stripes on paper.
Source V. Hartikainen