We saw above that predicting the future may be forbidden, this leads to an interesting question. Is one allowed to check the weather forecast?
In Parshas Achrei Mos (Vayikra 19:26) we learn about the issur of ולא תעוננו. Rashi explains: One who says ‘today is a good day to begin work’ or ‘this hour is dangerous to go out’ transgresses on לא תעוננו. The question is, is a meteorologist’s forecast considered to be in the same category?
According to the Rambam (Hilchos Avodas Zorah 11:8–9), the prohibition applies only when grounded in astrology. The weather forecast is based on physical atmospheric science, not astrological divination, therefore, it would clearly be permitted. However, the Beis Yosef (Yoreh Deah 179) understands in the Tur that ‘calculating hours and times’ violates לא תעוננו even without astrology. According to this, seemingly any systematic investigation of future conditions, including meteorology, would be forbidden. If so, what does the world rely on to be lenient with checking the forecast?
Another potential issur could be based on the Gemara in Pesachim (113b) that we mentioned above. The Gemara prohibits gazing at stars due to תמים תהיה עם ה' אלקיך. Rashi explains that תהיה תמים, obligates that one shouldn’t investigate the future, but should rather accept whatever comes his way with wholeness. Checking the forecast even without coming onto astrology would seemingly be included in this issur. Why is one checking, he should accept whatever Hashem sends his way?
Teshuvah from Rav Shamai Gross shlita
Rav Shamai Kehos HaKohen Gross shlita (Shu’t Shevet HaKehosi, Vol. 2, siman 322) writes that checking the weather forecast is perfectly permissible and is not a problem of תמים תהיה, as one is simply clarifying what is already in existence and is not predicting the future.
He cites an interesting proof from the Gemara in Yoma (21b). The Gemara relates that on motzei Yom Tov Achron of Succos everyone would look at the smoke rising from the misbayach. If it tilted northward, the poor rejoiced and homeowners were sad because heavy rainfall was coming. If the smoke tilted southwards etc. It is clear from this Gemara that there is nothing wrong with predicting the future weather. [This case of the Gemara is even worse, as they were predicting the future, whereas the weather forecast predicts things that are already present.]
Further Distinction Between Weather Forecast and Astrology
We can add, that logically it would seem obvious that one may check the weather forecast, as there is a big difference between a forecaster and an astrologer. A forecaster sees current atmospheric conditions — wind currents, air pressure systems, cloud formations — that ordinary people cannot perceive. A regular person sees dark clouds and knows rain is coming this afternoon; a forecaster reads airstreams hundreds of kilometers away and knows snow will fall on Mount Chermon within the week. This is categorically different from astrological predictions, where the future event is not yet in existence at all but is rather something that is going to be created in the near future.
Weather forecasting can be compared to planting a seed in the ground. We don’t call it ‘predicting the future’ to say a fruit tree will grow — the process already exists in potential; we are simply reading what is already present. Weather patterns work the same way.
As we saw above, according to many poskim, the heter to use alternative medicine is only when it works based on the present (such as determining allergies, working out what causes a headache), however, using it to predict the future (such as will this shidduch work well together, how many children will they have, how long will he live) is forbidden. Along these lines, clouds and air currents are present-state phenomena — they exist now, and the forecaster reads them, this is not like astrology which predicts things which are not currently present in the world.
Finally, according to the Ramban (cited in Beis Yosef, Yoreh De’ah 179) and the Gaon (Yoreh De’ah 179:7), the prohibition of astrology is to gaze at the stars to predict the future, however, once a person already possesses that knowledge, he may and should heed to it. Consequently, once meteorologists have already analyzed the atmospheric data and produced a forecast, it is entirely permitted to rely on their findings.
(This week’s write-up was based on Gilyon Oimek HaPeshat #80)
