Yes, a thwarted view would be disappointing, but there are options and anecdotes to calm your agitated soul.

If your observing site's weather may be marginal, consider traveling to the TROVE celebration near the Michigan-Indiana border.  Multiple attractions will insure a memorable 2012 Transit of Venus experience.  Immerse yourself in art exhibits, historical displays, planetarium programs, webcasts, public lectures, and even a Transit of Venus specialty beer!  At the fourth contact we will seal a Transit of Venus Time Keg, to be opened when the next transit of Venus pair approaches in 2117 and 2125.

If it's cloudy, you can still experience the transit of Venus in real time.  Complement your transit of Venus experience with views and commentary that are broadcast from around the world, including a live webcast from NASA EDGE or from SLOOH.  For more featured destinations, see Where to Be, or find a Sun-Earth Day Event Location through the interactive NASA map.

There is plenty of historical precedence for disappointment because of the vagaries of weather, but, hey, that's the nature of studying nature.  Many global expeditions outright failed due to poor weather.  Consider Henry A. Severn, pictured in New Zealand.  The article notes, "Mr. Severn's very complete and skilful arrangements were unfortunately defeated by cloudy weather occurring at the time of the transit.  Our readers will probably find it easier to sympathise with his disappointment than to realise his feelings on seeing the labour and preparation of years thus rendered useless by circumstances far beyond his own control.  Well might he exclaim, 'L'homme propose--Dieu dispose.'" 

You can still get value out of the transit of Venus experience even if clouds disappoint, as was the case for the team that went to Campbell Island in 1874.  The expedition's value was perhaps its better understanding of Campbell Island itself, an instance of looking around oneself to discover other aspects of the unique environment.

Similarly, in noting the diverse professional interests of his 1769 team--astronomy, geography, physics, and natural history--Chappe d'Auteroche wrote, "Whoever considers the prodigious extent of a passage of several thousand leagues, such as I was going to undertake; and reflects that one unlucky moment, the least intervening cloud , might in one day defeat all our hopes, and render fruitless so much toil and expence, will not wonder at my taking these precautions, to draw other advantages from this voyage: that in case we should be so unfortunate as to fail in our main purpose, we might in some measure make amends to the learned world for this loss."

Just because clouds threaten your viewing doesn't mean you should give up hope of seeing the sun.  Consider the experience of Robert Stawell Ball, who saw snow falling in front of his telescope concurrent with the 1882 transit of Venus.  He wrote, "Still, to have seen even a part of a transit of Venus is an event to remember for a lifetime, and we felt more delight than can be easily expressed at even this slight gleam of success."

In 2004, Becky Lowder, Assistant Director of the Georgia Southern Planetarium, made a move to find better circumstances.  Describing her pictures she wrote, "Wow, what an exciting event to experience!  In Statesboro, GA, our original observing site at Mill Creek Park was socked in thick with fog. After waiting to see the sun for about 25 min, with no luck of the fog burning off, we decided to head into town...to find the bright sunlight waiting for us!...WOW, it was so moving and thrilling to see Venus suspended in space between us and the sun!"

In 2004, this author was challenged with prospect of clouds obscuring the rising sun near the horizon while overhead was wonderfully clear.  Fortunately, the sun broke through in time for the gathered audience to marvel at the solar system in motion. 

Of course, there is always the legendary story of Le Gentil.  Thwarted by the Seven Years War from seeing the 1761 transit of Venus, Le Gentil waited eight years overseas to see the 1769 transit from seemingly idyllic Pondicherry, India.   Le Gentil writes, "During the whole month of May until the third of June, the mornings were very beautiful;  the weather was still of this same fineness the day before [the June 4th transit]."  To his dismay, on the morning of the 1769 transit, clouds rolled in and the wind blew with fury.  "That is the fate which often awaits astronomers.  I had gone more than ten thousand leagues; it seemed that I had crossed such a great expanse of seas, exiling myself from my native land, only to be the spectator of a fatal cloud  which came to place itself before the sun at the precise moment of my observation, to carry off from the the fruits of my pains and of my fatigues..." If an image from the title page of his memoirs is of Le Gentil himself, one can understand why he looks so glum.  May you not suffer from a fatal cloud.  [Image courtesy of University of Oklahoma Libraries, History of Science Collection]

And then there is the hellish weather on Venus.  After reading the meteorology report on our so-called sister planet, a gentle June rain doesn't seem so bad after all.