I have used a magnet on a disabled doorstop, its strength was more than enough to hold the door open in moderate winds. The rubber coating should work well in outdoor weather and also protect the contact point from scratches. I had to laminate the contact point on the door with a disc to make the door contact close more easily with the brake, but that little magnet is strong enough, that's the point.
50Pcs Neodymium Magnets With Countersunk Hole And Stainless Screws - Strong Rare Earth Magnets Disc For Locker, Tool Storage, Crafts By MIKEDE
42 Review
MIKEDE Strong Neodymium Disc Magnets, 16 Pack Powerful Permanent Rare Earth Magnets With Double-Sided Adhesive, Fridge, DIY, Building, Scientific, Craft, And Office Magnets, 1.26 Inch D X 1/8 Inch H
40 Review
Powerful Neodymium Bar Magnets With Double-Sided Adhesive - Ideal For Home, Office & Scientific Uses - Pack Of 16 Magnets
40 Review
16-Pack Powerful Neodymium Bar Magnets | MIKEDE Rare Earth π§² Metal Magnets with Double-Sided Adhesive | 60 x 10 x 3 mm
35 Review