Phone wind meter.

I have one of these:

shop.weatherflow.com/collections/meters

It seems pretty accurate but I don't bother with it anymore. I'm usually in a hurry and just rig up and get out there sailing.

If there are white caps... Its windy.

Over the years, I had only seen a handleful of times when people used an anemometer to check for wind speed, I actually bought an antique marine anemometer just out of curiosity. I never get to use it on the beach as I came to the conclusion that it is more of a gimmick than practical.

With the easy access of the Internet, we can access the local weather forecast readily. For a start, the synoptic charts give us a fair idea of the overall weather pattern. Then the more local wind measurements accurate measured in short intervals such as 20 minutes, give us the short-range forecast.

When you are down at the beach, you can use your experience by observing the activities around you. Where I sail, there is a clump of bushes. Further away, is a large tree. When the large tree sways rather moderately, it is going to be for a 5 sq M sail. If that short stubby bush sways wildly, definitely a 4 sq M weather.

Then the next near-precise estimation is the sand movements. If dry seaweeds and debris get blown around, then you need something less than a 5 sq M. If you get sand-basted, then perhaps you want to stay dry and watch the die-hard to strut their stuff. It is the kind of condition where you are no longer in control. The wind dictates you.

My son gave me one of these a couple of birthdays ago. I use it all the time to help choose what sail size to rig. I don't base my decision entirely on the reading, but use it in conjunction with, the water state, what others have rigged, wind readings from nearby wind stations etc. What I find most useful is that it shows how variable the wind is and I can use this info to decide if I want to rig for the gusts or the lulls.