An icy Hudson River
An icy Hudson River
An icy Hudson River

Daf Yomi Insights

By Rabbi Avrohom Sebrow

As the cold snap for our area continues, it might hearten us to know that people elsewhere have it worse. In Chicago, the temperature has already been below zero for 20 days this winter season. The modern record is 25 days, and that was set around a century ago. The current forecast calls for that record to be surpassed by this year’s cold streak. The National Weather Service in Lincoln reports the average temperature so far this winter (December through February 10) is just 19.2 degrees–making it the second-coldest since records have been kept, beginning in 1893. Here in New York, we are also experiencing record cold, just not as severe. On January 7, Central Park set a record for that date. It was the coldest in 118 years, as the temperature fell to just 5 degrees, breaking the record set in 1896 of 6 degrees.

Another sign that it is unusually cold in New York is that the East River Ferry had to suspend service because of ice in the water. Likewise regarding the Hudson River, sailors in Coast Guard icebreakers reported that they had never seen so much ice on the river before.

New York’s rivers were occasionally frozen in the 1800s. The Gothamist reports as follows:

January 1851: The East River was closed “so that both foot passengers and horses and sleighs” could cross the river in safety. The following day it was estimated that 15,000 had crossed the “ice bridge.”

January 1857: An ice bridge formed on the East River “in the space between the Fulton and Wall Street ferry slips . . . over to the Brooklyn piers. When the bridge broke up, a number of people were caught on the floes and were saved only by the tug Rattler, which rushed about and rescued the adventurers.”

Winter of 1867: The East River froze and prevented transit across it; it was at this time that it was decided a bridge needed to be built between Manhattan and Brooklyn, and the Brooklyn Bridge was born.

February 1875: For four days that month, the East River was frozen solid enough for people to walk over. The Hudson, too!

What is the connection between that time and now? Some scientists suggest the connection is the solar minimum. There’s a period referred to by climatologists as the Little Ice Age, a time in the 1600s when winters across the UK and Europe were often severe. The severe cold went hand-in-hand with an exceptionally inactive sun, which they referred to as the Maunder Minimum. NASA defines the Little Ice Age as a cold period between 1550 and 1850 and notes three particularly cold intervals: one beginning about 1650, another about 1770, and the last in 1850, each separated by intervals of slight warming.

In 2011, AccuWeather published an article that stated: “In a recent meeting, solar physicists from the Solar Physics Division of the American Astronomical Society predicted that the sun might enter an extended period of low activity, otherwise known as a ‘grand minimum.’”

Recently, scientists have become more convinced that the sun is becoming less active. The following is from a BBC article published three weeks ago: “‘I’ve been a solar physicist for 30 years, and I’ve never seen anything quite like this,’ says Richard Harrison, head of space physics at the Rutherford Appleton Laboratory in Oxfordshire. There is footage captured by spacecraft that have their sights trained on our star. The sun is revealed in exquisite detail, but its face is strangely featureless. ‘If you want to go back to see when the sun was this inactive . . . you’ve got to go back about 100 years,’ he says.”

Some scientists suggest that any effect of the solar minimum will be offset by global warming. Global warming itself has taken a hiatus and the average global temperature has actually cooled by 0.2 degrees Celsius (0.36 Fahrenheit) since 2001. This is a dirty little secret of the global warming fearmongers: that global temperatures haven’t risen for 15 years despite the record exhaust of greenhouse gases. Various theories have been suggested to explain this phenomenon. Some suggest that massive amounts of pollution particles produced by China reside in the atmosphere and stop some of the sun’s heat from reaching us. Another theory recently put forth is that Pacific winds are causing the oceans to absorb the heat.

With global warming taking a breather and a possible solar minimum, we may be in for some cold winters. Perhaps the cold weather might start a bit earlier in the season. The earliest date that New York City has had snowfall was October 10 (in 1925 and 1979), when trace amounts fell in Central Park. The earliest date that there was measurable snowfall in the city was October 15, 1876, when 0.5 inches fell in Central Park. The earliest date when 1 inch or more of snow has fallen in New York was on October 29, 2011. A total of 2.9 inches of snow fell then in Central Park. That was the first time New York City history that more than 1 inch of snow fell in the city in the months of October.

What does this have to do with the daf? This year Sukkos is rather late in the year, starting the night of October 8. Hoshanna Rabbah will be on October 15. It is conceivable that in New York we may have a covering of snow on our sukkos. The Shulchan Aruch codifies a halachah recorded in the mishnah in Sukkos (11a): A sukkah may be covered with any material that grows from the ground and is not susceptible to tumah. One may use tree branches or bamboo in their natural state as s’chach, as they meet both criteria. However, one may not use branches for s’chach that are still attached to a tree. Moreover, one should not even build a sukkah with detached branches if it is built under a tree. (There may be some instances where it is permissible.)

Water does not grow from the ground and may not be used as s’chach. How would one theoretically use water for s’chach? Perhaps someone could fashion sheets of ice that can be used as a ceiling. Sound far-fetched? There are at least five ice hotels worldwide that, as the name suggests, are fashioned primarily out of ice. You can find them in Japan, Norway, Sweden, Canada, and Romania.

What is the halachah if one has valid s’chach but it was blanketed with snow? Snow is a form of water and is not valid for s’chach. Does the snow covering the s’chach invalidate the sukkah?

The Shu’T Ginas V’radim says the answer may depend on a passage in Sukkah (13b). A person can contract tumah if he is under the same roof as a meis, a source of tumah. However, one does not need to be under a bona fide roof with a source of tumah to contract tumah; even a tree can serve as a halachic roof that conveys tumah. Kohanim are therefore careful not to walk under trees that have their canopies growing over graves in a cemetery. The tree can convey tumah from a grave to a kohen.

There is a dispute among the Rishonim about the following question: If a meis and a person are both under a large leafy vegetable, does the individual contract tumah? Rashi says he does because in its current state the vegetable may serve as a valid roof. The Meiri says on a biblical level the leafy vegetable cannot serve as a roof. Since it will quickly dry out and become minuscule, even when it is robust and lush it is not considered a roof.

Perhaps according to Rashi we should view the snow in its current state as being just like the leafy vegetable. Right now it is solid. The fact that it will melt later does not change its current status. This is similar to the lush vegetable that may serve as a halachic roof though it will wilt later. If that is the case, then the snow is considered an independent covering and invalidates the sukkah. One would not be able to eat in the sukkah until he clears off the snow. However, the Meiri should be unconcerned with the snow. It will melt eventually. Just as the leafy vegetable is of little halachic consequence because it will soon wilt, the snow is insignificant even now in its solid state because it will melt later. One would therefore be able to eat in the sukkah according to the Meiri without removing the snow first.

The Aruch HaShulchan says that one should definitely not recite a berachah of “Leishev Basukkah” when it is covered with snow.

May you add extra s’chach to keep your sukkah warm? The Shulchan Aruch writes that one should initially be able to see the stars through the s’chach. Nevertheless, the sukkah is still valid even if the stars cannot be seen. If the s’chach is layered thick to the point where rain cannot enter the sukkah, Rabbeinu Tam rules that the sukkah is invalid. Nevertheless, if one is unable to remove the s’chach, he may even use that sukkah with thick s’chach in time of need (M.B. 631:6).

The Gemara (8b) says that s’chach should be placed on the sukkah for purposes of shade. The Ritva explains that if someone placed s’chach on the sukkah for privacy, the sukkah is invalid. R’ Elyashiv, zt’l (quoted in Mishnah Berurah Dirshu edition) understood that the Gemara is even excluding s’chach placed for warmth. If someone made a sukkah and then added extra s’chach to keep his sukkah warm, that additional s’chach is not valid. Indeed, it may render the entire sukkah invalid. One can rectify the situation by removing the s’chach and placing it again for the dual purpose of shade and warmth.

Stay warm! v

The author thanks his brother Rabbi Yosef Sebrow for his extensive assistance with this article. Rabbi Avrohom Sebrow leads a daf yomi chaburah at Eitz Chayim of Dogwood Park in West Hempstead and is a rebbi at Mesivta Kesser Yisroel of Willowbrook. He can be contacted at


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