Mix together flour, parsley, baking powder, salt, thyme, and cumin in a large bowl. Add chopped onion and jalapeño pepper; mix until incorporated. Add salmon and eggs; mash salmon and mix until combined. Add water and stir until a thick batter forms.
Heat 1/4 inch oil in a frying pan just below the medium heat setting.
Working in batches of 3, drop 1 tablespoonful scoops of batter per fritter into hot oil; fry until golden brown, 3 to 5 minutes per side. Drain on a paper towel-lined plate. Repeat with remaining batter for about 16 fritters in total.