Your Website MUST be Mobile-Friendly by April 21st says Google
Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal.
This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high-quality search results that are optimized for their devices.
Bottom line: Your website must be mobile friendly!
Full details here: Mobile friendly search results notice.