The journal Impact Factor is the average number of times articles from the journal published in the past two years have been cited in the JCR year. The Impact Factor is calculated by dividing the number of citations in the JCR year by the total number of articles published in the two previous years.
You may be able to find the impact factor of 2016 journals in the year 2018
Another way is to 1st verify if the journal is listed under Thomson reuters from: http://ip-science.thomsonreuters.com/mjl/. And then check the corresponding website or use ISSN number. The impact factor mention there will be listed by JCR, even if they haven't mentioned on website.
Oh yeh, i just discovered the mistake. Of course i was speeking about the 2015/2016 used in conjonction with the JCRfullcoverlist-2016. IF are given through the link w3.scijournal.org for each journal. I'm seeking for the file.
A key question to ask you is: why do you need it? The IF is discredited as a method of ranking journals, or individuals who publish in a particular journal. As a minor fact, fine, but if it is an important component of what you are researching I would be very concerned.
There are several ranking bodies that engaged in identification and publication of high impact factor journal these include; Thomson Reuters, Times Higher Education, etc. so you can their sites.
The impact factor of journals of a particular year is published by Thompson Reuters by mid-next year. The 1916 impact factor will be available around June his year. Nowadays a large number of organizations(>20) are providing impact factors of journals. Still JCR impact factors published by Thompson Reuters are considered to be the best