HAHA funniest thing I have heard- its random.Its not random at all.Because of clouds and rain, the signal is weakened and so we can't get a signal.As one person said " have got signals in heavy rains, and got no signal at all under clear skies."First of all, the signals are uplinked to Tata Sky's satellite from a center in Delhi.If the sky is clear in your city but its raining heavily in Delhi, you will have signal problems because the signals cannot be uplinked to the satellite at the center in Delhi.Secondly, there are many factors which affect signal, apart from rain and cloud cover, sun outage is also one factor. Even though proper sun outage only occurs a few times a yr, partial sun outage occurs nearly everyday. On some days, the solar radiation will affect the signals much more than on other days and you'll experience weaker signals.Thirdly, sometimes even though it is raining heavily, you will receive a good signal. I am not sure how or why it happens.