Coming to the end of the second rainy day in a row, this rabbi wonders if it might not be sheer coincidence that two nights ago we began the seasonal addition of "veten tal umatar livrakhah" ("and grant dew and rain as a blessing") into the sixth baqashah / request of the weekday Amidah. Of course, says my rational side, God does not really work that way, and anyway the request is for Israel, not here.
Meanwhile, the very idea that we make this request at all is curious. The obligation to do so is described in Mishnah Ta'anit, accompanied by an explanation for its timing:
אין שואלים את הגשמים, אלא סמוך לגשמים
They only ask for rain when it is close to the rainy season. (Ta'anit 1:2)
Israel, though located in the Fertile Crescent of the Middle East, does not receive any rain at all from roughly March to October. One might think that we should ask for rain year-round, because every little bit helps. And given how important rain was to the livelihoods of our agricultural ancestors, it might be expected to be a consistent theme in daily prayer.
But there is also a rabbinic principle that we should only tell others what they are ready or willing to hear, and extending that logic to prayer, we should only make requests are within the realm of possibility. There is no point in asking for rain in the Israeli summer, because it simply isn't going to happen. By the time we start adding this to our weekday tefillot, there is a good chance that rain might fall.
So regardless of how wet it might be in New York, now is absolutely the time to pray for rain. Stay dry!
Rabbi Seth Adelson