Hi, please have a look here TFA Dostmann la Crosse 30-32xx Temperature Humidity outdoor sensor rc-switch. The used protocol seems similar to the alecto protocol.
At start I used remote_receiver with a raw dump and a rc_switch dump to see if the bit data are received.
remote_receiver:
pin: GPIO04
# dump: rc_switch
tolerance: # signal receive is very sensitive to this tolerance!
type: percentage
value: 55% # I don't know why?
filter: 100us # rc-switch differs heavily from result, greater 200us no data ??
idle: 4ms # sync is about 4 * 1.7 ms
With this knowledge you have to find your relevant bits in the bit stream. Again the RTL-433 project may be a great help.
Good luck.