If you're trying to learn to sail (on any boat really, but especially a Hobie 16), you will want to stay with windspeed of about the 5 to 10 mph range. Any less than 5 mph, and the wind will likely be too flukey for you to get a good sense of what's going on. Any more than 10mph, and things will likely happen so quickly that you risk capsizing or getting out of control. Tacking and staying upwind also become difficult. As you get better, the wind limit basically depends on you. Top sailors can handle 30mph wind or occasionally more.
The suggestion of starting with a Sunfish or other small dinghy is a good one. These boats are relatively cheap (used), readily available, hold their resale value, and do a good job of teaching you the basics. After a year, you sell the Sunfish and move up to a Hobie.
I concur, but the wind speeds are relatively progressive. When first learning to sail, (I learned to sail on a H16, solo) I used to pray for 5 mph winds. After a while, I use to pray for 10 mph winds but it is at that point, the water gets to be a little rough (white caps begin at about that wind spead). As time went on, I ended up praying for 20 mph winds with the waves and swells. It's all about overcoming your fears.
When I first purchaced my boat, I just wanted to day sail. Then one day, two guys with a boat just like mine went flying by me, one hull out of the water, both trapped out in harnesses. This was the beginning of my addiction. I knew I wanted to do "THAT !!!"
But know that in order for you to make these transitions, you will have to capsize. Once I realized that capsizing was not a "death sentence," I began to push my limits and overcome more fears. If you just want to day sail solo (as "Bodhi" has already mentioned), then look for a smaller boat. However, if you're in good health and/or plan on having a crew, or you want to achieve a level of performance that will make your heart beat about 200 times a minute, get a Hobie 16. Just my 4 cents !!!