Unknown; all Rattata

5 species to catch in 1 area of this location, across 2 game versions.

Data from Pokemon SoulSilver only: exact levels and the encounter rate for each Pokémon.

in tall grass

Conditional slots 3 for 3 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Rattata	radio off	20	10%
Zigzagoon	radio on Hoenn Sound	20	10%
Bidoof	radio on Sinnoh Sound	20	10%

while surfing (Surf)

with the Good Rod

with the Old Rod

with the Super Rod