Shemini Atzeres Mashiv Haruach U’morid Hageshem

If you are davening without a minyan, wait before davening Musaf until you are sure the minyan has already davened Musaf, so you can say morid hageshem.

If you did not yet daven Shacharis and you heard the gabbai announce “Mashiv haruach u’morid hageshem,” say morid hageshem during Shacharis as well (unless you are davening Shacharis with a later minyan).

If you said Morid hatal instead of Mashiv haruach u’morid hageshem, continue as usual and do not go back, even if you have not yet finished the berachah.

The fifth aliyah ends with the words va’achos Tuval Kayin Naamah (4:22), and the sixth aliyah ends with the words ki lakach oso Elokim (5:24).