Raining animals - such as fish or frogs have often been documented and considered to be due to a meteorological event and there are people who attribute recent examples to such a cause.
This link covers numerous recent events and hypotheses - and with such wide ranging opinion it's hard to reach a sensible conclusion.
Astrologers use information based on connections made by the planets, sun and moon in our known solar system and taking a look at any likely candidates to explain a sequence of events like this you would have to consider Jupiter -the planet resonating with the keywords "mass" or "large" and Uranus - "sudden", "unusual" - and the fact that these two planets are currently moving side by side in outer space - basically sharing their magnetic fields and reinforcing their stand-out qualities - and the zodiac sector they are moving through - is Pisces. The sign of water and fish. Jupiter connects to flocks, swarms as examples of masses. Uranus is the sky energy -connecting to all thing in that domain -hence, birds - so together there is already a signature on one level of species en masse that inhabit the air and the sea. Fish and birds.
The brilliance of astrology is that it describes energy in such a multi-dimensional way - so every combination of energy like Jupiter and Uranus conjunct in Pisces can be expressed in collection of statements, describing how that energy expresses in different contexts.
For example: Jupiter keyword big + Uranus electricity or electromagnetic force + water = electrocution
as noted in these recent news events. Remembering that the bodies of mammals such as humans are primarily composed of water means a hi voltage charge is usually lethal - and the risk is higher throughout January 2011
Recently, globally we have seen the pisces keyword "water" mixed with "sudden"(uranus) and "big" (jupiter) affecting our global weather - ranging from rain to flood to snow - extra big, unusual and unprecedented also apply here to the water, running or frigid as ice and snow, that have affected our world to a great degree in geographically disparate places - such is the power of large planetary effects impacting on planet Earth.
Pisces has another keyword - "gas" which is a term for silent often odourless, often lethal chemicals which we encounter in our daily lives - oxygen being the one vital for survival, carbon dioxide the one we exhale, carbon monoxide the one emitted by your car engine. Another gas we hear about sometimes is methane - you may be interested to know more about this natural gas, a naturally forming product from the earth, which has numerous uses, but one which has a nasty and dangerous side. Though not toxic in itself it is highly flammable and therefore explosive, plus it displaces oxygen and therefore results in death if the level of methane is high.
One current condition applying, due to the mix we have in place, is that high (Jupiter) levels of gas (Pisces) are creating an explosive or sudden shock events (Uranus) just as high (Jupiter) levels of water/snow/ice (Pisces) have been creating sudden/unusual/disruptive/dangerous (Uranus) conditions while this pattern has strengthened during December 2010 into New Year 2011
So it is truly a season of mis-adventure with extra care needed around water/snow/ice, electricity, gases.
Considering the high gas level indicator and sudden shock or explosive events an interesting link is the gas methane as a possible cause of recent seemingly unrelated events: mass bird deaths, mass fish/sea creature deaths as well as the number of methane gas explosions - notably in coal mines where the gas is a high level hazard due to natural emission.
What causes a coal mine explosion?
Trapped Methane gas produced in the ages of carbonization of organic matter in contact with air (oxygen) pumped in the tunnel for ventilation explodes violently when in contact with a spark/flame during tunneling/drilling is the usual cause.( source:Answers.com)
Obviously modern mining takes into account the known chemistry of mines and yet, as in examples like in New Zealand November 19 2010, the Pike River Mine exploded ( Jupiter "big" and Pisces "gas" were strongly accentuated at this date) and a government enquiry is set to determine why. Coal mine explosions in the news in 2010 show this was something to take note of.
The point is: what if the levels of methane have suddenly shot up globally due to changes in the earth's structure, rifts and tearing of the crust, permitting even more methane to burst through breaches. The tested levels of methane globally are known to be on the increase.
This global map from Wikimedia Commons shows the parts per million typical distribution being highest (red) in the upper latitudes
"By 2010, methane levels, at least in the Arctic, were measured at 1850 ppb, a level scientists described as being higher than at any time in the previous 400,000 years" quoted on the Methane site Wikipedia
So we know methane is increasing and an interesting question now is - what if there have been sudden surges causing a string of events we are unaccustomed to? It makes a lot of sense when the current planetary profiles affecting us are examined.