If one mistakenly said Visein Tal Umatar between Shemini Atzeres and the 7th of Marcheshvan, is he to repeat Shemoneh Esrei?
Some Poskim rule that one who said Visein Tal Umatar after Sukkos, prior to the 7th of Marcheshvan in Eretz Yisrael or prior to the 5th of December in the Diaspora, is not required to repeat Shemoneh Esrei. This applies whether in Eretz Yisrael or the Diaspora. From majority of Poskim, however, it is evident that one must repeat the prayer if Visein Tal Umatar was recited prior to the 7th of Cheshvan, whether in Eretz Yisrael, and certainly in other lands, and so practically rule some of today’s Poskim. Practically, according to Admur, the prayer is to be repeated.
 Toras Chaim 3/3 [Maharchash-Rav Chaim Shabsi of Salunki, Greece 1600] brought in Rav Akiva Eiger 117; Tehila Ledavid 117/1-2; Toras Chaim Sofer 117/6; Orchos Chaim Spinka 117/1; Rav SZ”A in Halichos Shlomo 8/18; Or Letziyon 2/7-31; Yabia Omer 5/15; 10/10; The following Rishonim rule that one may even initially ask for rain in Eretz Yisrael from after Sukkos: Ritva.
 The reason: As after Sukkos it is no longer a Siman Kelala to have rain, and thus we begin saying Mashiv Haruach, and only when it’s a Siman Kelala do we make one repeat Shemoneh Esrei. [Toras Chaim ibid; Tehila Ledavid ibid; Toras Chaim Sofer ibid]
 Poskim ibid
Does this apply in all countries that don’t need rain before the 7th of Marcheshvan? Some of the Poskim ibid imply that their ruling applies in all countries, as there is no country in which rain is a Siman Kelala after Sukkos. This is also implied from the fact they plainly state that in all the Diaspora there is no need to repeat Shemoneh Esrei without making any differentiation. [See Toras Chaim and Toras Chaim Sofer ibid] However the Tehila Ledavid ibid implies that this ruling only applies to lands that need rain after Sukkos, and not to all lands.
 See Michaber 117/1 and 117/3; Admur 117/1; Mateh Moshe 1/141; Elya Raba 117/3; Radbaz 6/2; Olas Tamid 117/3; Kneses Hagedola 117; Beir Heiytiv 117/6; Biur Halacha 117/1 “Hatzerichim”; Ketzos Hashulchan 21/8
Background: So is implied from Setimas Haposkim who do not state that after Sukkos, before 7th of Cheshvan, has a different status: See Michaber 117/1 “In the rain season one must say Visein Tal Umatar and in…Eretz Yisrael one begins from the 7th of Cheshvan.” Then in Michaber 117/3 “If one asked for rain in the summer months he must repeat”; So also rules without making a differentiation all other Poskim who record this Halacha. In addition, it is clearly evident from the following Poskim that prior to the 7th of Cheshvan one must repeat Shemoneh Esrei, as they rule that in the Diaspora Bedieved one need not repeat Shemoneh Esrei if he said Visein Tal Umatar prior to the 5th of December. However, they stipulate that this only applies after the 7th of Cheshvan, hence implying that if it was said before the 7th of Cheshvan then it needs to be repeated: So rules: Admur 117/1; Mateh Moshe 1/141; Olas Tamid 117/3; Kneses Hagedola 117; Elya Raba 117/3; Beir Heiytiv 117/6; Biur Halacha 117/1 “Hatzerichim”; Ketzos Hashulchan 21/8
 Chazon Ish in Dinim Vehanhagos 4/26; Lehoros Nasan 7/5; Avnei Yishpa 1/16; Koveitz Mibeis Levi 17/99 in name of Rav Wozner
 The reason: Possibly the reason is as follows: a) Once the Sages made their Takana not to say Visein Tal Umatar before the 7th of Cheshvan, Shemoneh Esrei must be repeated if one made a mistake, as although it is not a Siman Kelala, since in majority of the summer it is a Siman Kelala, therefore they did not differentiate in their decree. [See Admur 114/5 for a similar ruling regarding one who said Mashiv Haruach during after Pesach when it is still the rain season] b) Perhaps it is a Siman Kelala to have rain fall on the pilgrims returning from Jerusalem! Now, although we said before that if an entire country needs rain in the summer, then Bedieved if one requested in the summer he does not need to repeat, and the same should seemingly apply here, that if the country needs rain after Sukkos they should not need to repeat, seemingly that was only said regarding countries with a summer rain season, while those with a winter rainseason, must wait unti the 7th of Cheshvan.
 See Admur 117/1; Unedited Sicha of 7th of Cheshvan 1986 [printed in Hisvadyus 1986 1 p. 509] “It is forbidden to ask for rain prior to the 7th of Cheshvan and if one does so he does not fulfill his obligation and must repeat the prayer”; However, in the tape of this Sicha the Rebbe stated that there is a question in what to do if one did so, and did not give a final ruling on the subject.
Background: See Admur 117/1 “The same applies if in these lands an individual made a mistake and asked for rain from the 7th of Cheshvan and onwards he is not required to repeat” Thus, clearly implying that before the 7th he must repeat, unlike the ruling of the former Poskim who say no one has to repeat starting from after Sukkos. This is furthermore implied from the fact Admur ibid limits the ruling of the Mateh Moshe to only “these lands”, hence proving that not being a Siman Kelala is not enough and there has to actually be in need for rain. This defies the entire reason of logic of the lenient Poskim.