You're welcome montoya, the online wind chart at my local shows the average and gust wind speed, so it's easy to see when those two lines are separated by 10kt or more. The conditions become difficult, with the gusts overpowering you and then you need to work the kite to keep going in the lulls. With experience you'll know which size kite to take out for the conditions at your local spot. If not at your local, introduce yourself and ask a local, you never know if you'll soon need their help!
Sometimes it's interesting to watch people new to a spot, they'll arrive and start running lines, pump a kite and gear up without taking 5-10 mins to observe conditions and local behaviours. I'll usually go say hi, have a chat and see if they've been here before, offer a launch even.
Here's an example from today, I was out on my 12m a the time where the gusts peaked just under 30kt. I noticed a few gusts had me letting go of the bar to sheet out and occasionally I needed a little trim/depower but most of the time wind speed was just right to leave the trim/depower fullly out. In the lulls I needed to work the kite to keep speed and full sheet out through the gusts. Had a beginner out, I helped him launch and he handled conditions ok on his 12m, I saw him get overpowered a couple of times, landing face first, but he'd get back up and go. For context, that's about a 7-8kt delta.