Does weather forecasting come under the heading of astrology or claiming to know the unseen?
Question

                There are some weather sites on the internet which forecast the weather that is expected in the next 5-10 days. Is it permissible for me to visit them? I am asking this question because I am afraid that they may be claiming to have knowledge of the unseen or it may be a kind of astrology, in which case it is haraam for me to visit them.
Praise be to Allah.Forecasting 
    the weather does not come under the heading of astrology or claiming to have 
    knowledge of the unseen, rather it is based on physical evidence and 
    experience, and study of the natural laws established by Allaah. The same 
    applies to knowing the times of solar and lunar eclipses, or when there are 
    likely to be strong winds and rainfall. 
It says in
    Fataawa al-Lajnah al-Daa’imah: The time of solar and lunar eclipses 
    may be known from calculating the movements of heavenly bodies, from which 
    it may also be known whether the eclipse will be total or partial. There is 
    nothing strange about that, because this is not a matter of the unseen for 
    everyone, rather it is only “unseen” for those who have no knowledge of 
    astronomy and it is not “unseen” for those who have knowledge of this 
    science. That does not mean that solar and lunar eclipses are not among the 
    signs of Allaah with which He instils fear in His slaves so as to bring them 
    back to their Lord and to obedience to Him.
 It also 
    says: 
Forecasting 
    the weather and predicting strong winds and storms or saying where clouds 
    are expected to form or where rain is likely to fall is based on knowledge 
    of the natural laws of Allaah. One who has experience of these laws may say 
    what he expects to happen, without certain knowledge, on the basis of 
    scientific theories or common experience, so he expects that and predicts it 
    on the basis of likelihood, not certain knowledge, and he gets it right 
    sometimes and gets it wrong sometimes. End quote from Fataawa al-Lajnah 
    al-Daa’imah.  
Shaykh Ibn 
    ‘Uthaymeen (may Allaah have mercy on him) said: The one who speaks of that 
    which may be worked out by calculations is not a fortune-teller at all, 
    because there is no element of fortune-telling in that which may be worked 
    out by calculations. If a person predicts a solar or lunar eclipse, this is 
    not fortune-telling because it is worked out by calculations. If he says 
    that the sun will set at a 20-degree angle at such and such a time, this is 
    not knowledge of the unseen, because it is something that may be worked out 
    by calculations, and predicting something that can be worked out by 
    calculation, even if it is in the future, is not regarded as being knowledge 
    of the unseen, or fortune-telling. 
Is 
    twenty-four hour weather reporting such as we have now fortune-telling? 
The answer 
    is no, because it is also based on scientific data which is describing 
    climatic conditions, because climatic conditions have to do with precise 
    measurements that are known to them. Thus they may predict that certain 
    conditions are likely to produce rain or not. That is like the primitive 
    predication that we make when we see clouds forming, and thunder and 
    lightning and thick clouds, and we say: “It is going to rain soon.” 
What matters 
    is that what points to physical phenomena is not knowledge of the unseen, 
    even if some of the common folk think that these things are matters of the 
    unseen and say that believing in them is like believing in fortune-telling. 
End quote 
    from al-Qawl al-Mufeed Sharh Kitaab al-Tawheed. 
See 
    al-Fataawa al-Kubra by Shaykh al-Islam Ibn Taymiyah (4/424) with regard 
    to the knowledge of astronomers about the times of solar and lunar eclipses, 
    the beginning of spring and winter, and other matters that may be known by 
    means of calculations and are not matters of the unseen. 
And Allaah 
    knows best.